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Diffstat (limited to 'arch/x86/kvm/emulate.c')
| -rw-r--r-- | arch/x86/kvm/emulate.c | 5849 |
1 files changed, 5849 insertions, 0 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c new file mode 100644 index 000000000..63754d248 --- /dev/null +++ b/arch/x86/kvm/emulate.c @@ -0,0 +1,5849 @@ +/****************************************************************************** + * emulate.c + * + * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. + * + * Copyright (c) 2005 Keir Fraser + * + * Linux coding style, mod r/m decoder, segment base fixes, real-mode + * privileged instructions: + * + * Copyright (C) 2006 Qumranet + * Copyright 2010 Red Hat, Inc. and/or its affiliates. + * + * Avi Kivity <avi@qumranet.com> + * Yaniv Kamay <yaniv@qumranet.com> + * + * This work is licensed under the terms of the GNU GPL, version 2. See + * the COPYING file in the top-level directory. + * + * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 + */ + +#include <linux/kvm_host.h> +#include "kvm_cache_regs.h" +#include <asm/kvm_emulate.h> +#include <linux/stringify.h> +#include <asm/debugreg.h> +#include <asm/nospec-branch.h> + +#include "x86.h" +#include "tss.h" +#include "mmu.h" +#include "pmu.h" + +/* + * Operand types + */ +#define OpNone 0ull +#define OpImplicit 1ull /* No generic decode */ +#define OpReg 2ull /* Register */ +#define OpMem 3ull /* Memory */ +#define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */ +#define OpDI 5ull /* ES:DI/EDI/RDI */ +#define OpMem64 6ull /* Memory, 64-bit */ +#define OpImmUByte 7ull /* Zero-extended 8-bit immediate */ +#define OpDX 8ull /* DX register */ +#define OpCL 9ull /* CL register (for shifts) */ +#define OpImmByte 10ull /* 8-bit sign extended immediate */ +#define OpOne 11ull /* Implied 1 */ +#define OpImm 12ull /* Sign extended up to 32-bit immediate */ +#define OpMem16 13ull /* Memory operand (16-bit). */ +#define OpMem32 14ull /* Memory operand (32-bit). */ +#define OpImmU 15ull /* Immediate operand, zero extended */ +#define OpSI 16ull /* SI/ESI/RSI */ +#define OpImmFAddr 17ull /* Immediate far address */ +#define OpMemFAddr 18ull /* Far address in memory */ +#define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */ +#define OpES 20ull /* ES */ +#define OpCS 21ull /* CS */ +#define OpSS 22ull /* SS */ +#define OpDS 23ull /* DS */ +#define OpFS 24ull /* FS */ +#define OpGS 25ull /* GS */ +#define OpMem8 26ull /* 8-bit zero extended memory operand */ +#define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */ +#define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */ +#define OpAccLo 29ull /* Low part of extended acc (AX/AX/EAX/RAX) */ +#define OpAccHi 30ull /* High part of extended acc (-/DX/EDX/RDX) */ + +#define OpBits 5 /* Width of operand field */ +#define OpMask ((1ull << OpBits) - 1) + +/* + * Opcode effective-address decode tables. + * Note that we only emulate instructions that have at least one memory + * operand (excluding implicit stack references). We assume that stack + * references and instruction fetches will never occur in special memory + * areas that require emulation. So, for example, 'mov <imm>,<reg>' need + * not be handled. + */ + +/* Operand sizes: 8-bit operands or specified/overridden size. */ +#define ByteOp (1<<0) /* 8-bit operands. */ +/* Destination operand type. */ +#define DstShift 1 +#define ImplicitOps (OpImplicit << DstShift) +#define DstReg (OpReg << DstShift) +#define DstMem (OpMem << DstShift) +#define DstAcc (OpAcc << DstShift) +#define DstDI (OpDI << DstShift) +#define DstMem64 (OpMem64 << DstShift) +#define DstMem16 (OpMem16 << DstShift) +#define DstImmUByte (OpImmUByte << DstShift) +#define DstDX (OpDX << DstShift) +#define DstAccLo (OpAccLo << DstShift) +#define DstMask (OpMask << DstShift) +/* Source operand type. */ +#define SrcShift 6 +#define SrcNone (OpNone << SrcShift) +#define SrcReg (OpReg << SrcShift) +#define SrcMem (OpMem << SrcShift) +#define SrcMem16 (OpMem16 << SrcShift) +#define SrcMem32 (OpMem32 << SrcShift) +#define SrcImm (OpImm << SrcShift) +#define SrcImmByte (OpImmByte << SrcShift) +#define SrcOne (OpOne << SrcShift) +#define SrcImmUByte (OpImmUByte << SrcShift) +#define SrcImmU (OpImmU << SrcShift) +#define SrcSI (OpSI << SrcShift) +#define SrcXLat (OpXLat << SrcShift) +#define SrcImmFAddr (OpImmFAddr << SrcShift) +#define SrcMemFAddr (OpMemFAddr << SrcShift) +#define SrcAcc (OpAcc << SrcShift) +#define SrcImmU16 (OpImmU16 << SrcShift) +#define SrcImm64 (OpImm64 << SrcShift) +#define SrcDX (OpDX << SrcShift) +#define SrcMem8 (OpMem8 << SrcShift) +#define SrcAccHi (OpAccHi << SrcShift) +#define SrcMask (OpMask << SrcShift) +#define BitOp (1<<11) +#define MemAbs (1<<12) /* Memory operand is absolute displacement */ +#define String (1<<13) /* String instruction (rep capable) */ +#define Stack (1<<14) /* Stack instruction (push/pop) */ +#define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */ +#define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */ +#define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ +#define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ +#define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ +#define Escape (5<<15) /* Escape to coprocessor instruction */ +#define InstrDual (6<<15) /* Alternate instruction decoding of mod == 3 */ +#define ModeDual (7<<15) /* Different instruction for 32/64 bit */ +#define Sse (1<<18) /* SSE Vector instruction */ +/* Generic ModRM decode. */ +#define ModRM (1<<19) +/* Destination is only written; never read. */ +#define Mov (1<<20) +/* Misc flags */ +#define Prot (1<<21) /* instruction generates #UD if not in prot-mode */ +#define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */ +#define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ +#define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ +#define Undefined (1<<25) /* No Such Instruction */ +#define Lock (1<<26) /* lock prefix is allowed for the instruction */ +#define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ +#define No64 (1<<28) +#define PageTable (1 << 29) /* instruction used to write page table */ +#define NotImpl (1 << 30) /* instruction is not implemented */ +/* Source 2 operand type */ +#define Src2Shift (31) +#define Src2None (OpNone << Src2Shift) +#define Src2Mem (OpMem << Src2Shift) +#define Src2CL (OpCL << Src2Shift) +#define Src2ImmByte (OpImmByte << Src2Shift) +#define Src2One (OpOne << Src2Shift) +#define Src2Imm (OpImm << Src2Shift) +#define Src2ES (OpES << Src2Shift) +#define Src2CS (OpCS << Src2Shift) +#define Src2SS (OpSS << Src2Shift) +#define Src2DS (OpDS << Src2Shift) +#define Src2FS (OpFS << Src2Shift) +#define Src2GS (OpGS << Src2Shift) +#define Src2Mask (OpMask << Src2Shift) +#define Mmx ((u64)1 << 40) /* MMX Vector instruction */ +#define AlignMask ((u64)7 << 41) +#define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */ +#define Unaligned ((u64)2 << 41) /* Explicitly unaligned (e.g. MOVDQU) */ +#define Avx ((u64)3 << 41) /* Advanced Vector Extensions */ +#define Aligned16 ((u64)4 << 41) /* Aligned to 16 byte boundary (e.g. FXSAVE) */ +#define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ +#define NoWrite ((u64)1 << 45) /* No writeback */ +#define SrcWrite ((u64)1 << 46) /* Write back src operand */ +#define NoMod ((u64)1 << 47) /* Mod field is ignored */ +#define Intercept ((u64)1 << 48) /* Has valid intercept field */ +#define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */ +#define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */ +#define NearBranch ((u64)1 << 52) /* Near branches */ +#define No16 ((u64)1 << 53) /* No 16 bit operand */ +#define IncSP ((u64)1 << 54) /* SP is incremented before ModRM calc */ +#define TwoMemOp ((u64)1 << 55) /* Instruction has two memory operand */ + +#define DstXacc (DstAccLo | SrcAccHi | SrcWrite) + +#define X2(x...) x, x +#define X3(x...) X2(x), x +#define X4(x...) X2(x), X2(x) +#define X5(x...) X4(x), x +#define X6(x...) X4(x), X2(x) +#define X7(x...) X4(x), X3(x) +#define X8(x...) X4(x), X4(x) +#define X16(x...) X8(x), X8(x) + +#define NR_FASTOP (ilog2(sizeof(ulong)) + 1) +#define FASTOP_SIZE 8 + +/* + * fastop functions have a special calling convention: + * + * dst: rax (in/out) + * src: rdx (in/out) + * src2: rcx (in) + * flags: rflags (in/out) + * ex: rsi (in:fastop pointer, out:zero if exception) + * + * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for + * different operand sizes can be reached by calculation, rather than a jump + * table (which would be bigger than the code). + * + * fastop functions are declared as taking a never-defined fastop parameter, + * so they can't be called from C directly. + */ + +struct fastop; + +struct opcode { + u64 flags : 56; + u64 intercept : 8; + union { + int (*execute)(struct x86_emulate_ctxt *ctxt); + const struct opcode *group; + const struct group_dual *gdual; + const struct gprefix *gprefix; + const struct escape *esc; + const struct instr_dual *idual; + const struct mode_dual *mdual; + void (*fastop)(struct fastop *fake); + } u; + int (*check_perm)(struct x86_emulate_ctxt *ctxt); +}; + +struct group_dual { + struct opcode mod012[8]; + struct opcode mod3[8]; +}; + +struct gprefix { + struct opcode pfx_no; + struct opcode pfx_66; + struct opcode pfx_f2; + struct opcode pfx_f3; +}; + +struct escape { + struct opcode op[8]; + struct opcode high[64]; +}; + +struct instr_dual { + struct opcode mod012; + struct opcode mod3; +}; + +struct mode_dual { + struct opcode mode32; + struct opcode mode64; +}; + +#define EFLG_RESERVED_ZEROS_MASK 0xffc0802a + +enum x86_transfer_type { + X86_TRANSFER_NONE, + X86_TRANSFER_CALL_JMP, + X86_TRANSFER_RET, + X86_TRANSFER_TASK_SWITCH, +}; + +static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + if (!(ctxt->regs_valid & (1 << nr))) { + ctxt->regs_valid |= 1 << nr; + ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); + } + return ctxt->_regs[nr]; +} + +static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + ctxt->regs_valid |= 1 << nr; + ctxt->regs_dirty |= 1 << nr; + return &ctxt->_regs[nr]; +} + +static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr) +{ + reg_read(ctxt, nr); + return reg_write(ctxt, nr); +} + +static void writeback_registers(struct x86_emulate_ctxt *ctxt) +{ + unsigned reg; + + for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16) + ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]); +} + +static void invalidate_registers(struct x86_emulate_ctxt *ctxt) +{ + ctxt->regs_dirty = 0; + ctxt->regs_valid = 0; +} + +/* + * These EFLAGS bits are restored from saved value during emulation, and + * any changes are written back to the saved value after emulation. + */ +#define EFLAGS_MASK (X86_EFLAGS_OF|X86_EFLAGS_SF|X86_EFLAGS_ZF|X86_EFLAGS_AF|\ + X86_EFLAGS_PF|X86_EFLAGS_CF) + +#ifdef CONFIG_X86_64 +#define ON64(x) x +#else +#define ON64(x) +#endif + +static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)); + +#define FOP_FUNC(name) \ + ".align " __stringify(FASTOP_SIZE) " \n\t" \ + ".type " name ", @function \n\t" \ + name ":\n\t" + +#define FOP_RET "ret \n\t" + +#define FOP_START(op) \ + extern void em_##op(struct fastop *fake); \ + asm(".pushsection .text, \"ax\" \n\t" \ + ".global em_" #op " \n\t" \ + FOP_FUNC("em_" #op) + +#define FOP_END \ + ".popsection") + +#define FOPNOP() \ + FOP_FUNC(__stringify(__UNIQUE_ID(nop))) \ + FOP_RET + +#define FOP1E(op, dst) \ + FOP_FUNC(#op "_" #dst) \ + "10: " #op " %" #dst " \n\t" FOP_RET + +#define FOP1EEX(op, dst) \ + FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception) + +#define FASTOP1(op) \ + FOP_START(op) \ + FOP1E(op##b, al) \ + FOP1E(op##w, ax) \ + FOP1E(op##l, eax) \ + ON64(FOP1E(op##q, rax)) \ + FOP_END + +/* 1-operand, using src2 (for MUL/DIV r/m) */ +#define FASTOP1SRC2(op, name) \ + FOP_START(name) \ + FOP1E(op, cl) \ + FOP1E(op, cx) \ + FOP1E(op, ecx) \ + ON64(FOP1E(op, rcx)) \ + FOP_END + +/* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */ +#define FASTOP1SRC2EX(op, name) \ + FOP_START(name) \ + FOP1EEX(op, cl) \ + FOP1EEX(op, cx) \ + FOP1EEX(op, ecx) \ + ON64(FOP1EEX(op, rcx)) \ + FOP_END + +#define FOP2E(op, dst, src) \ + FOP_FUNC(#op "_" #dst "_" #src) \ + #op " %" #src ", %" #dst " \n\t" FOP_RET + +#define FASTOP2(op) \ + FOP_START(op) \ + FOP2E(op##b, al, dl) \ + FOP2E(op##w, ax, dx) \ + FOP2E(op##l, eax, edx) \ + ON64(FOP2E(op##q, rax, rdx)) \ + FOP_END + +/* 2 operand, word only */ +#define FASTOP2W(op) \ + FOP_START(op) \ + FOPNOP() \ + FOP2E(op##w, ax, dx) \ + FOP2E(op##l, eax, edx) \ + ON64(FOP2E(op##q, rax, rdx)) \ + FOP_END + +/* 2 operand, src is CL */ +#define FASTOP2CL(op) \ + FOP_START(op) \ + FOP2E(op##b, al, cl) \ + FOP2E(op##w, ax, cl) \ + FOP2E(op##l, eax, cl) \ + ON64(FOP2E(op##q, rax, cl)) \ + FOP_END + +/* 2 operand, src and dest are reversed */ +#define FASTOP2R(op, name) \ + FOP_START(name) \ + FOP2E(op##b, dl, al) \ + FOP2E(op##w, dx, ax) \ + FOP2E(op##l, edx, eax) \ + ON64(FOP2E(op##q, rdx, rax)) \ + FOP_END + +#define FOP3E(op, dst, src, src2) \ + FOP_FUNC(#op "_" #dst "_" #src "_" #src2) \ + #op " %" #src2 ", %" #src ", %" #dst " \n\t" FOP_RET + +/* 3-operand, word-only, src2=cl */ +#define FASTOP3WCL(op) \ + FOP_START(op) \ + FOPNOP() \ + FOP3E(op##w, ax, dx, cl) \ + FOP3E(op##l, eax, edx, cl) \ + ON64(FOP3E(op##q, rax, rdx, cl)) \ + FOP_END + +/* Special case for SETcc - 1 instruction per cc */ +#define FOP_SETCC(op) \ + ".align 4 \n\t" \ + ".type " #op ", @function \n\t" \ + #op ": \n\t" \ + #op " %al \n\t" \ + FOP_RET + +asm(".pushsection .fixup, \"ax\"\n" + ".global kvm_fastop_exception \n" + "kvm_fastop_exception: xor %esi, %esi; ret\n" + ".popsection"); + +FOP_START(setcc) +FOP_SETCC(seto) +FOP_SETCC(setno) +FOP_SETCC(setc) +FOP_SETCC(setnc) +FOP_SETCC(setz) +FOP_SETCC(setnz) +FOP_SETCC(setbe) +FOP_SETCC(setnbe) +FOP_SETCC(sets) +FOP_SETCC(setns) +FOP_SETCC(setp) +FOP_SETCC(setnp) +FOP_SETCC(setl) +FOP_SETCC(setnl) +FOP_SETCC(setle) +FOP_SETCC(setnle) +FOP_END; + +FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET +FOP_END; + +/* + * XXX: inoutclob user must know where the argument is being expanded. + * Relying on CONFIG_CC_HAS_ASM_GOTO would allow us to remove _fault. + */ +#define asm_safe(insn, inoutclob...) \ +({ \ + int _fault = 0; \ + \ + asm volatile("1:" insn "\n" \ + "2:\n" \ + ".pushsection .fixup, \"ax\"\n" \ + "3: movl $1, %[_fault]\n" \ + " jmp 2b\n" \ + ".popsection\n" \ + _ASM_EXTABLE(1b, 3b) \ + : [_fault] "+qm"(_fault) inoutclob ); \ + \ + _fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \ +}) + +static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, + enum x86_intercept intercept, + enum x86_intercept_stage stage) +{ + struct x86_instruction_info info = { + .intercept = intercept, + .rep_prefix = ctxt->rep_prefix, + .modrm_mod = ctxt->modrm_mod, + .modrm_reg = ctxt->modrm_reg, + .modrm_rm = ctxt->modrm_rm, + .src_val = ctxt->src.val64, + .dst_val = ctxt->dst.val64, + .src_bytes = ctxt->src.bytes, + .dst_bytes = ctxt->dst.bytes, + .ad_bytes = ctxt->ad_bytes, + .next_rip = ctxt->eip, + }; + + return ctxt->ops->intercept(ctxt, &info, stage); +} + +static void assign_masked(ulong *dest, ulong src, ulong mask) +{ + *dest = (*dest & ~mask) | (src & mask); +} + +static void assign_register(unsigned long *reg, u64 val, int bytes) +{ + /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ + switch (bytes) { + case 1: + *(u8 *)reg = (u8)val; + break; + case 2: + *(u16 *)reg = (u16)val; + break; + case 4: + *reg = (u32)val; + break; /* 64b: zero-extend */ + case 8: + *reg = val; + break; + } +} + +static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt) +{ + return (1UL << (ctxt->ad_bytes << 3)) - 1; +} + +static ulong stack_mask(struct x86_emulate_ctxt *ctxt) +{ + u16 sel; + struct desc_struct ss; + + if (ctxt->mode == X86EMUL_MODE_PROT64) + return ~0UL; + ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS); + return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */ +} + +static int stack_size(struct x86_emulate_ctxt *ctxt) +{ + return (__fls(stack_mask(ctxt)) + 1) >> 3; +} + +/* Access/update address held in a register, based on addressing mode. */ +static inline unsigned long +address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg) +{ + if (ctxt->ad_bytes == sizeof(unsigned long)) + return reg; + else + return reg & ad_mask(ctxt); +} + +static inline unsigned long +register_address(struct x86_emulate_ctxt *ctxt, int reg) +{ + return address_mask(ctxt, reg_read(ctxt, reg)); +} + +static void masked_increment(ulong *reg, ulong mask, int inc) +{ + assign_masked(reg, *reg + inc, mask); +} + +static inline void +register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc) +{ + ulong *preg = reg_rmw(ctxt, reg); + + assign_register(preg, *preg + inc, ctxt->ad_bytes); +} + +static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc) +{ + masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc); +} + +static u32 desc_limit_scaled(struct desc_struct *desc) +{ + u32 limit = get_desc_limit(desc); + + return desc->g ? (limit << 12) | 0xfff : limit; +} + +static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) +{ + if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) + return 0; + + return ctxt->ops->get_cached_segment_base(ctxt, seg); +} + +static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, + u32 error, bool valid) +{ + WARN_ON(vec > 0x1f); + ctxt->exception.vector = vec; + ctxt->exception.error_code = error; + ctxt->exception.error_code_valid = valid; + return X86EMUL_PROPAGATE_FAULT; +} + +static int emulate_db(struct x86_emulate_ctxt *ctxt) +{ + return emulate_exception(ctxt, DB_VECTOR, 0, false); +} + +static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) +{ + return emulate_exception(ctxt, GP_VECTOR, err, true); +} + +static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err) +{ + return emulate_exception(ctxt, SS_VECTOR, err, true); +} + +static int emulate_ud(struct x86_emulate_ctxt *ctxt) +{ + return emulate_exception(ctxt, UD_VECTOR, 0, false); +} + +static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) +{ + return emulate_exception(ctxt, TS_VECTOR, err, true); +} + +static int emulate_de(struct x86_emulate_ctxt *ctxt) +{ + return emulate_exception(ctxt, DE_VECTOR, 0, false); +} + +static int emulate_nm(struct x86_emulate_ctxt *ctxt) +{ + return emulate_exception(ctxt, NM_VECTOR, 0, false); +} + +static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) +{ + u16 selector; + struct desc_struct desc; + + ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); + return selector; +} + +static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, + unsigned seg) +{ + u16 dummy; + u32 base3; + struct desc_struct desc; + + ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); + ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); +} + +/* + * x86 defines three classes of vector instructions: explicitly + * aligned, explicitly unaligned, and the rest, which change behaviour + * depending on whether they're AVX encoded or not. + * + * Also included is CMPXCHG16B which is not a vector instruction, yet it is + * subject to the same check. FXSAVE and FXRSTOR are checked here too as their + * 512 bytes of data must be aligned to a 16 byte boundary. + */ +static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size) +{ + u64 alignment = ctxt->d & AlignMask; + + if (likely(size < 16)) + return 1; + + switch (alignment) { + case Unaligned: + case Avx: + return 1; + case Aligned16: + return 16; + case Aligned: + default: + return size; + } +} + +static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + unsigned *max_size, unsigned size, + bool write, bool fetch, + enum x86emul_mode mode, ulong *linear) +{ + struct desc_struct desc; + bool usable; + ulong la; + u32 lim; + u16 sel; + u8 va_bits; + + la = seg_base(ctxt, addr.seg) + addr.ea; + *max_size = 0; + switch (mode) { + case X86EMUL_MODE_PROT64: + *linear = la; + va_bits = ctxt_virt_addr_bits(ctxt); + if (get_canonical(la, va_bits) != la) + goto bad; + + *max_size = min_t(u64, ~0u, (1ull << va_bits) - la); + if (size > *max_size) + goto bad; + break; + default: + *linear = la = (u32)la; + usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, + addr.seg); + if (!usable) + goto bad; + /* code segment in protected mode or read-only data segment */ + if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8)) + || !(desc.type & 2)) && write) + goto bad; + /* unreadable code segment */ + if (!fetch && (desc.type & 8) && !(desc.type & 2)) + goto bad; + lim = desc_limit_scaled(&desc); + if (!(desc.type & 8) && (desc.type & 4)) { + /* expand-down segment */ + if (addr.ea <= lim) + goto bad; + lim = desc.d ? 0xffffffff : 0xffff; + } + if (addr.ea > lim) + goto bad; + if (lim == 0xffffffff) + *max_size = ~0u; + else { + *max_size = (u64)lim + 1 - addr.ea; + if (size > *max_size) + goto bad; + } + break; + } + if (la & (insn_alignment(ctxt, size) - 1)) + return emulate_gp(ctxt, 0); + return X86EMUL_CONTINUE; +bad: + if (addr.seg == VCPU_SREG_SS) + return emulate_ss(ctxt, 0); + else + return emulate_gp(ctxt, 0); +} + +static int linearize(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + unsigned size, bool write, + ulong *linear) +{ + unsigned max_size; + return __linearize(ctxt, addr, &max_size, size, write, false, + ctxt->mode, linear); +} + +static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst, + enum x86emul_mode mode) +{ + ulong linear; + int rc; + unsigned max_size; + struct segmented_address addr = { .seg = VCPU_SREG_CS, + .ea = dst }; + + if (ctxt->op_bytes != sizeof(unsigned long)) + addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1); + rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear); + if (rc == X86EMUL_CONTINUE) + ctxt->_eip = addr.ea; + return rc; +} + +static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst) +{ + return assign_eip(ctxt, dst, ctxt->mode); +} + +static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst, + const struct desc_struct *cs_desc) +{ + enum x86emul_mode mode = ctxt->mode; + int rc; + +#ifdef CONFIG_X86_64 + if (ctxt->mode >= X86EMUL_MODE_PROT16) { + if (cs_desc->l) { + u64 efer = 0; + + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + if (efer & EFER_LMA) + mode = X86EMUL_MODE_PROT64; + } else + mode = X86EMUL_MODE_PROT32; /* temporary value */ + } +#endif + if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32) + mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; + rc = assign_eip(ctxt, dst, mode); + if (rc == X86EMUL_CONTINUE) + ctxt->mode = mode; + return rc; +} + +static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) +{ + return assign_eip_near(ctxt, ctxt->_eip + rel); +} + +static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear, + void *data, unsigned size) +{ + return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, true); +} + +static int linear_write_system(struct x86_emulate_ctxt *ctxt, + ulong linear, void *data, + unsigned int size) +{ + return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, true); +} + +static int segmented_read_std(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + void *data, + unsigned size) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, addr, size, false, &linear); + if (rc != X86EMUL_CONTINUE) + return rc; + return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, false); +} + +static int segmented_write_std(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + void *data, + unsigned int size) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, addr, size, true, &linear); + if (rc != X86EMUL_CONTINUE) + return rc; + return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, false); +} + +/* + * Prefetch the remaining bytes of the instruction without crossing page + * boundary if they are not in fetch_cache yet. + */ +static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size) +{ + int rc; + unsigned size, max_size; + unsigned long linear; + int cur_size = ctxt->fetch.end - ctxt->fetch.data; + struct segmented_address addr = { .seg = VCPU_SREG_CS, + .ea = ctxt->eip + cur_size }; + + /* + * We do not know exactly how many bytes will be needed, and + * __linearize is expensive, so fetch as much as possible. We + * just have to avoid going beyond the 15 byte limit, the end + * of the segment, or the end of the page. + * + * __linearize is called with size 0 so that it does not do any + * boundary check itself. Instead, we use max_size to check + * against op_size. + */ + rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode, + &linear); + if (unlikely(rc != X86EMUL_CONTINUE)) + return rc; + + size = min_t(unsigned, 15UL ^ cur_size, max_size); + size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear)); + + /* + * One instruction can only straddle two pages, + * and one has been loaded at the beginning of + * x86_decode_insn. So, if not enough bytes + * still, we must have hit the 15-byte boundary. + */ + if (unlikely(size < op_size)) + return emulate_gp(ctxt, 0); + + rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end, + size, &ctxt->exception); + if (unlikely(rc != X86EMUL_CONTINUE)) + return rc; + ctxt->fetch.end += size; + return X86EMUL_CONTINUE; +} + +static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, + unsigned size) +{ + unsigned done_size = ctxt->fetch.end - ctxt->fetch.ptr; + + if (unlikely(done_size < size)) + return __do_insn_fetch_bytes(ctxt, size - done_size); + else + return X86EMUL_CONTINUE; +} + +/* Fetch next part of the instruction being emulated. */ +#define insn_fetch(_type, _ctxt) \ +({ _type _x; \ + \ + rc = do_insn_fetch_bytes(_ctxt, sizeof(_type)); \ + if (rc != X86EMUL_CONTINUE) \ + goto done; \ + ctxt->_eip += sizeof(_type); \ + memcpy(&_x, ctxt->fetch.ptr, sizeof(_type)); \ + ctxt->fetch.ptr += sizeof(_type); \ + _x; \ +}) + +#define insn_fetch_arr(_arr, _size, _ctxt) \ +({ \ + rc = do_insn_fetch_bytes(_ctxt, _size); \ + if (rc != X86EMUL_CONTINUE) \ + goto done; \ + ctxt->_eip += (_size); \ + memcpy(_arr, ctxt->fetch.ptr, _size); \ + ctxt->fetch.ptr += (_size); \ +}) + +/* + * Given the 'reg' portion of a ModRM byte, and a register block, return a + * pointer into the block that addresses the relevant register. + * @highbyte_regs specifies whether to decode AH,CH,DH,BH. + */ +static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, + int byteop) +{ + void *p; + int highbyte_regs = (ctxt->rex_prefix == 0) && byteop; + + if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) + p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; + else + p = reg_rmw(ctxt, modrm_reg); + return p; +} + +static int read_descriptor(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + u16 *size, unsigned long *address, int op_bytes) +{ + int rc; + + if (op_bytes == 2) + op_bytes = 3; + *address = 0; + rc = segmented_read_std(ctxt, addr, size, 2); + if (rc != X86EMUL_CONTINUE) + return rc; + addr.ea += 2; + rc = segmented_read_std(ctxt, addr, address, op_bytes); + return rc; +} + +FASTOP2(add); +FASTOP2(or); +FASTOP2(adc); +FASTOP2(sbb); +FASTOP2(and); +FASTOP2(sub); +FASTOP2(xor); +FASTOP2(cmp); +FASTOP2(test); + +FASTOP1SRC2(mul, mul_ex); +FASTOP1SRC2(imul, imul_ex); +FASTOP1SRC2EX(div, div_ex); +FASTOP1SRC2EX(idiv, idiv_ex); + +FASTOP3WCL(shld); +FASTOP3WCL(shrd); + +FASTOP2W(imul); + +FASTOP1(not); +FASTOP1(neg); +FASTOP1(inc); +FASTOP1(dec); + +FASTOP2CL(rol); +FASTOP2CL(ror); +FASTOP2CL(rcl); +FASTOP2CL(rcr); +FASTOP2CL(shl); +FASTOP2CL(shr); +FASTOP2CL(sar); + +FASTOP2W(bsf); +FASTOP2W(bsr); +FASTOP2W(bt); +FASTOP2W(bts); +FASTOP2W(btr); +FASTOP2W(btc); + +FASTOP2(xadd); + +FASTOP2R(cmp, cmp_r); + +static int em_bsf_c(struct x86_emulate_ctxt *ctxt) +{ + /* If src is zero, do not writeback, but update flags */ + if (ctxt->src.val == 0) + ctxt->dst.type = OP_NONE; + return fastop(ctxt, em_bsf); +} + +static int em_bsr_c(struct x86_emulate_ctxt *ctxt) +{ + /* If src is zero, do not writeback, but update flags */ + if (ctxt->src.val == 0) + ctxt->dst.type = OP_NONE; + return fastop(ctxt, em_bsr); +} + +static __always_inline u8 test_cc(unsigned int condition, unsigned long flags) +{ + u8 rc; + void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf); + + flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; + asm("push %[flags]; popf; " CALL_NOSPEC + : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags)); + return rc; +} + +static void fetch_register_operand(struct operand *op) +{ + switch (op->bytes) { + case 1: + op->val = *(u8 *)op->addr.reg; + break; + case 2: + op->val = *(u16 *)op->addr.reg; + break; + case 4: + op->val = *(u32 *)op->addr.reg; + break; + case 8: + op->val = *(u64 *)op->addr.reg; + break; + } +} + +static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) +{ + switch (reg) { + case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break; + case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break; + case 2: asm("movdqa %%xmm2, %0" : "=m"(*data)); break; + case 3: asm("movdqa %%xmm3, %0" : "=m"(*data)); break; + case 4: asm("movdqa %%xmm4, %0" : "=m"(*data)); break; + case 5: asm("movdqa %%xmm5, %0" : "=m"(*data)); break; + case 6: asm("movdqa %%xmm6, %0" : "=m"(*data)); break; + case 7: asm("movdqa %%xmm7, %0" : "=m"(*data)); break; +#ifdef CONFIG_X86_64 + case 8: asm("movdqa %%xmm8, %0" : "=m"(*data)); break; + case 9: asm("movdqa %%xmm9, %0" : "=m"(*data)); break; + case 10: asm("movdqa %%xmm10, %0" : "=m"(*data)); break; + case 11: asm("movdqa %%xmm11, %0" : "=m"(*data)); break; + case 12: asm("movdqa %%xmm12, %0" : "=m"(*data)); break; + case 13: asm("movdqa %%xmm13, %0" : "=m"(*data)); break; + case 14: asm("movdqa %%xmm14, %0" : "=m"(*data)); break; + case 15: asm("movdqa %%xmm15, %0" : "=m"(*data)); break; +#endif + default: BUG(); + } +} + +static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, + int reg) +{ + switch (reg) { + case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break; + case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break; + case 2: asm("movdqa %0, %%xmm2" : : "m"(*data)); break; + case 3: asm("movdqa %0, %%xmm3" : : "m"(*data)); break; + case 4: asm("movdqa %0, %%xmm4" : : "m"(*data)); break; + case 5: asm("movdqa %0, %%xmm5" : : "m"(*data)); break; + case 6: asm("movdqa %0, %%xmm6" : : "m"(*data)); break; + case 7: asm("movdqa %0, %%xmm7" : : "m"(*data)); break; +#ifdef CONFIG_X86_64 + case 8: asm("movdqa %0, %%xmm8" : : "m"(*data)); break; + case 9: asm("movdqa %0, %%xmm9" : : "m"(*data)); break; + case 10: asm("movdqa %0, %%xmm10" : : "m"(*data)); break; + case 11: asm("movdqa %0, %%xmm11" : : "m"(*data)); break; + case 12: asm("movdqa %0, %%xmm12" : : "m"(*data)); break; + case 13: asm("movdqa %0, %%xmm13" : : "m"(*data)); break; + case 14: asm("movdqa %0, %%xmm14" : : "m"(*data)); break; + case 15: asm("movdqa %0, %%xmm15" : : "m"(*data)); break; +#endif + default: BUG(); + } +} + +static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) +{ + switch (reg) { + case 0: asm("movq %%mm0, %0" : "=m"(*data)); break; + case 1: asm("movq %%mm1, %0" : "=m"(*data)); break; + case 2: asm("movq %%mm2, %0" : "=m"(*data)); break; + case 3: asm("movq %%mm3, %0" : "=m"(*data)); break; + case 4: asm("movq %%mm4, %0" : "=m"(*data)); break; + case 5: asm("movq %%mm5, %0" : "=m"(*data)); break; + case 6: asm("movq %%mm6, %0" : "=m"(*data)); break; + case 7: asm("movq %%mm7, %0" : "=m"(*data)); break; + default: BUG(); + } +} + +static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg) +{ + switch (reg) { + case 0: asm("movq %0, %%mm0" : : "m"(*data)); break; + case 1: asm("movq %0, %%mm1" : : "m"(*data)); break; + case 2: asm("movq %0, %%mm2" : : "m"(*data)); break; + case 3: asm("movq %0, %%mm3" : : "m"(*data)); break; + case 4: asm("movq %0, %%mm4" : : "m"(*data)); break; + case 5: asm("movq %0, %%mm5" : : "m"(*data)); break; + case 6: asm("movq %0, %%mm6" : : "m"(*data)); break; + case 7: asm("movq %0, %%mm7" : : "m"(*data)); break; + default: BUG(); + } +} + +static int em_fninit(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + asm volatile("fninit"); + return X86EMUL_CONTINUE; +} + +static int em_fnstcw(struct x86_emulate_ctxt *ctxt) +{ + u16 fcw; + + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + asm volatile("fnstcw %0": "+m"(fcw)); + + ctxt->dst.val = fcw; + + return X86EMUL_CONTINUE; +} + +static int em_fnstsw(struct x86_emulate_ctxt *ctxt) +{ + u16 fsw; + + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + asm volatile("fnstsw %0": "+m"(fsw)); + + ctxt->dst.val = fsw; + + return X86EMUL_CONTINUE; +} + +static void decode_register_operand(struct x86_emulate_ctxt *ctxt, + struct operand *op) +{ + unsigned reg = ctxt->modrm_reg; + + if (!(ctxt->d & ModRM)) + reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); + + if (ctxt->d & Sse) { + op->type = OP_XMM; + op->bytes = 16; + op->addr.xmm = reg; + read_sse_reg(ctxt, &op->vec_val, reg); + return; + } + if (ctxt->d & Mmx) { + reg &= 7; + op->type = OP_MM; + op->bytes = 8; + op->addr.mm = reg; + return; + } + + op->type = OP_REG; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp); + + fetch_register_operand(op); + op->orig_val = op->val; +} + +static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg) +{ + if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP) + ctxt->modrm_seg = VCPU_SREG_SS; +} + +static int decode_modrm(struct x86_emulate_ctxt *ctxt, + struct operand *op) +{ + u8 sib; + int index_reg, base_reg, scale; + int rc = X86EMUL_CONTINUE; + ulong modrm_ea = 0; + + ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */ + index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */ + base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */ + + ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6; + ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; + ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07); + ctxt->modrm_seg = VCPU_SREG_DS; + + if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) { + op->type = OP_REG; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, + ctxt->d & ByteOp); + if (ctxt->d & Sse) { + op->type = OP_XMM; + op->bytes = 16; + op->addr.xmm = ctxt->modrm_rm; + read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm); + return rc; + } + if (ctxt->d & Mmx) { + op->type = OP_MM; + op->bytes = 8; + op->addr.mm = ctxt->modrm_rm & 7; + return rc; + } + fetch_register_operand(op); + return rc; + } + + op->type = OP_MEM; + + if (ctxt->ad_bytes == 2) { + unsigned bx = reg_read(ctxt, VCPU_REGS_RBX); + unsigned bp = reg_read(ctxt, VCPU_REGS_RBP); + unsigned si = reg_read(ctxt, VCPU_REGS_RSI); + unsigned di = reg_read(ctxt, VCPU_REGS_RDI); + + /* 16-bit ModR/M decode. */ + switch (ctxt->modrm_mod) { + case 0: + if (ctxt->modrm_rm == 6) + modrm_ea += insn_fetch(u16, ctxt); + break; + case 1: + modrm_ea += insn_fetch(s8, ctxt); + break; + case 2: + modrm_ea += insn_fetch(u16, ctxt); + break; + } + switch (ctxt->modrm_rm) { + case 0: + modrm_ea += bx + si; + break; + case 1: + modrm_ea += bx + di; + break; + case 2: + modrm_ea += bp + si; + break; + case 3: + modrm_ea += bp + di; + break; + case 4: + modrm_ea += si; + break; + case 5: + modrm_ea += di; + break; + case 6: + if (ctxt->modrm_mod != 0) + modrm_ea += bp; + break; + case 7: + modrm_ea += bx; + break; + } + if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 || + (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0)) + ctxt->modrm_seg = VCPU_SREG_SS; + modrm_ea = (u16)modrm_ea; + } else { + /* 32/64-bit ModR/M decode. */ + if ((ctxt->modrm_rm & 7) == 4) { + sib = insn_fetch(u8, ctxt); + index_reg |= (sib >> 3) & 7; + base_reg |= sib & 7; + scale = sib >> 6; + + if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0) + modrm_ea += insn_fetch(s32, ctxt); + else { + modrm_ea += reg_read(ctxt, base_reg); + adjust_modrm_seg(ctxt, base_reg); + /* Increment ESP on POP [ESP] */ + if ((ctxt->d & IncSP) && + base_reg == VCPU_REGS_RSP) + modrm_ea += ctxt->op_bytes; + } + if (index_reg != 4) + modrm_ea += reg_read(ctxt, index_reg) << scale; + } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) { + modrm_ea += insn_fetch(s32, ctxt); + if (ctxt->mode == X86EMUL_MODE_PROT64) + ctxt->rip_relative = 1; + } else { + base_reg = ctxt->modrm_rm; + modrm_ea += reg_read(ctxt, base_reg); + adjust_modrm_seg(ctxt, base_reg); + } + switch (ctxt->modrm_mod) { + case 1: + modrm_ea += insn_fetch(s8, ctxt); + break; + case 2: + modrm_ea += insn_fetch(s32, ctxt); + break; + } + } + op->addr.mem.ea = modrm_ea; + if (ctxt->ad_bytes != 8) + ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea; + +done: + return rc; +} + +static int decode_abs(struct x86_emulate_ctxt *ctxt, + struct operand *op) +{ + int rc = X86EMUL_CONTINUE; + + op->type = OP_MEM; + switch (ctxt->ad_bytes) { + case 2: + op->addr.mem.ea = insn_fetch(u16, ctxt); + break; + case 4: + op->addr.mem.ea = insn_fetch(u32, ctxt); + break; + case 8: + op->addr.mem.ea = insn_fetch(u64, ctxt); + break; + } +done: + return rc; +} + +static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt) +{ + long sv = 0, mask; + + if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) { + mask = ~((long)ctxt->dst.bytes * 8 - 1); + + if (ctxt->src.bytes == 2) + sv = (s16)ctxt->src.val & (s16)mask; + else if (ctxt->src.bytes == 4) + sv = (s32)ctxt->src.val & (s32)mask; + else + sv = (s64)ctxt->src.val & (s64)mask; + + ctxt->dst.addr.mem.ea = address_mask(ctxt, + ctxt->dst.addr.mem.ea + (sv >> 3)); + } + + /* only subword offset */ + ctxt->src.val &= (ctxt->dst.bytes << 3) - 1; +} + +static int read_emulated(struct x86_emulate_ctxt *ctxt, + unsigned long addr, void *dest, unsigned size) +{ + int rc; + struct read_cache *mc = &ctxt->mem_read; + + if (mc->pos < mc->end) + goto read_cached; + + WARN_ON((mc->end + size) >= sizeof(mc->data)); + + rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size, + &ctxt->exception); + if (rc != X86EMUL_CONTINUE) + return rc; + + mc->end += size; + +read_cached: + memcpy(dest, mc->data + mc->pos, size); + mc->pos += size; + return X86EMUL_CONTINUE; +} + +static int segmented_read(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + void *data, + unsigned size) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, addr, size, false, &linear); + if (rc != X86EMUL_CONTINUE) + return rc; + return read_emulated(ctxt, linear, data, size); +} + +static int segmented_write(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + const void *data, + unsigned size) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, addr, size, true, &linear); + if (rc != X86EMUL_CONTINUE) + return rc; + return ctxt->ops->write_emulated(ctxt, linear, data, size, + &ctxt->exception); +} + +static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt, + struct segmented_address addr, + const void *orig_data, const void *data, + unsigned size) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, addr, size, true, &linear); + if (rc != X86EMUL_CONTINUE) + return rc; + return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data, + size, &ctxt->exception); +} + +static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, + unsigned int size, unsigned short port, + void *dest) +{ + struct read_cache *rc = &ctxt->io_read; + + if (rc->pos == rc->end) { /* refill pio read ahead */ + unsigned int in_page, n; + unsigned int count = ctxt->rep_prefix ? + address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1; + in_page = (ctxt->eflags & X86_EFLAGS_DF) ? + offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) : + PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)); + n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count); + if (n == 0) + n = 1; + rc->pos = rc->end = 0; + if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n)) + return 0; + rc->end = n * size; + } + + if (ctxt->rep_prefix && (ctxt->d & String) && + !(ctxt->eflags & X86_EFLAGS_DF)) { + ctxt->dst.data = rc->data + rc->pos; + ctxt->dst.type = OP_MEM_STR; + ctxt->dst.count = (rc->end - rc->pos) / size; + rc->pos = rc->end; + } else { + memcpy(dest, rc->data + rc->pos, size); + rc->pos += size; + } + return 1; +} + +static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt, + u16 index, struct desc_struct *desc) +{ + struct desc_ptr dt; + ulong addr; + + ctxt->ops->get_idt(ctxt, &dt); + + if (dt.size < index * 8 + 7) + return emulate_gp(ctxt, index << 3 | 0x2); + + addr = dt.address + index * 8; + return linear_read_system(ctxt, addr, desc, sizeof *desc); +} + +static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, + u16 selector, struct desc_ptr *dt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + u32 base3 = 0; + + if (selector & 1 << 2) { + struct desc_struct desc; + u16 sel; + + memset (dt, 0, sizeof *dt); + if (!ops->get_segment(ctxt, &sel, &desc, &base3, + VCPU_SREG_LDTR)) + return; + + dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ + dt->address = get_desc_base(&desc) | ((u64)base3 << 32); + } else + ops->get_gdt(ctxt, dt); +} + +static int get_descriptor_ptr(struct x86_emulate_ctxt *ctxt, + u16 selector, ulong *desc_addr_p) +{ + struct desc_ptr dt; + u16 index = selector >> 3; + ulong addr; + + get_descriptor_table_ptr(ctxt, selector, &dt); + + if (dt.size < index * 8 + 7) + return emulate_gp(ctxt, selector & 0xfffc); + + addr = dt.address + index * 8; + +#ifdef CONFIG_X86_64 + if (addr >> 32 != 0) { + u64 efer = 0; + + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + if (!(efer & EFER_LMA)) + addr &= (u32)-1; + } +#endif + + *desc_addr_p = addr; + return X86EMUL_CONTINUE; +} + +/* allowed just for 8 bytes segments */ +static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, + u16 selector, struct desc_struct *desc, + ulong *desc_addr_p) +{ + int rc; + + rc = get_descriptor_ptr(ctxt, selector, desc_addr_p); + if (rc != X86EMUL_CONTINUE) + return rc; + + return linear_read_system(ctxt, *desc_addr_p, desc, sizeof(*desc)); +} + +/* allowed just for 8 bytes segments */ +static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, + u16 selector, struct desc_struct *desc) +{ + int rc; + ulong addr; + + rc = get_descriptor_ptr(ctxt, selector, &addr); + if (rc != X86EMUL_CONTINUE) + return rc; + + return linear_write_system(ctxt, addr, desc, sizeof *desc); +} + +static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, + u16 selector, int seg, u8 cpl, + enum x86_transfer_type transfer, + struct desc_struct *desc) +{ + struct desc_struct seg_desc, old_desc; + u8 dpl, rpl; + unsigned err_vec = GP_VECTOR; + u32 err_code = 0; + bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ + ulong desc_addr; + int ret; + u16 dummy; + u32 base3 = 0; + + memset(&seg_desc, 0, sizeof seg_desc); + + if (ctxt->mode == X86EMUL_MODE_REAL) { + /* set real mode segment descriptor (keep limit etc. for + * unreal mode) */ + ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg); + set_desc_base(&seg_desc, selector << 4); + goto load; + } else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) { + /* VM86 needs a clean new segment descriptor */ + set_desc_base(&seg_desc, selector << 4); + set_desc_limit(&seg_desc, 0xffff); + seg_desc.type = 3; + seg_desc.p = 1; + seg_desc.s = 1; + seg_desc.dpl = 3; + goto load; + } + + rpl = selector & 3; + + /* TR should be in GDT only */ + if (seg == VCPU_SREG_TR && (selector & (1 << 2))) + goto exception; + + /* NULL selector is not valid for TR, CS and (except for long mode) SS */ + if (null_selector) { + if (seg == VCPU_SREG_CS || seg == VCPU_SREG_TR) + goto exception; + + if (seg == VCPU_SREG_SS) { + if (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl) + goto exception; + + /* + * ctxt->ops->set_segment expects the CPL to be in + * SS.DPL, so fake an expand-up 32-bit data segment. + */ + seg_desc.type = 3; + seg_desc.p = 1; + seg_desc.s = 1; + seg_desc.dpl = cpl; + seg_desc.d = 1; + seg_desc.g = 1; + } + + /* Skip all following checks */ + goto load; + } + + ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr); + if (ret != X86EMUL_CONTINUE) + return ret; + + err_code = selector & 0xfffc; + err_vec = (transfer == X86_TRANSFER_TASK_SWITCH) ? TS_VECTOR : + GP_VECTOR; + + /* can't load system descriptor into segment selector */ + if (seg <= VCPU_SREG_GS && !seg_desc.s) { + if (transfer == X86_TRANSFER_CALL_JMP) + return X86EMUL_UNHANDLEABLE; + goto exception; + } + + dpl = seg_desc.dpl; + + switch (seg) { + case VCPU_SREG_SS: + /* + * segment is not a writable data segment or segment + * selector's RPL != CPL or segment selector's RPL != CPL + */ + if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) + goto exception; + break; + case VCPU_SREG_CS: + if (!(seg_desc.type & 8)) + goto exception; + + if (seg_desc.type & 4) { + /* conforming */ + if (dpl > cpl) + goto exception; + } else { + /* nonconforming */ + if (rpl > cpl || dpl != cpl) + goto exception; + } + /* in long-mode d/b must be clear if l is set */ + if (seg_desc.d && seg_desc.l) { + u64 efer = 0; + + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + if (efer & EFER_LMA) + goto exception; + } + + /* CS(RPL) <- CPL */ + selector = (selector & 0xfffc) | cpl; + break; + case VCPU_SREG_TR: + if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) + goto exception; + if (!seg_desc.p) { + err_vec = NP_VECTOR; + goto exception; + } + old_desc = seg_desc; + seg_desc.type |= 2; /* busy */ + ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc, + sizeof(seg_desc), &ctxt->exception); + if (ret != X86EMUL_CONTINUE) + return ret; + break; + case VCPU_SREG_LDTR: + if (seg_desc.s || seg_desc.type != 2) + goto exception; + break; + default: /* DS, ES, FS, or GS */ + /* + * segment is not a data or readable code segment or + * ((segment is a data or nonconforming code segment) + * and (both RPL and CPL > DPL)) + */ + if ((seg_desc.type & 0xa) == 0x8 || + (((seg_desc.type & 0xc) != 0xc) && + (rpl > dpl && cpl > dpl))) + goto exception; + break; + } + + if (!seg_desc.p) { + err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; + goto exception; + } + + if (seg_desc.s) { + /* mark segment as accessed */ + if (!(seg_desc.type & 1)) { + seg_desc.type |= 1; + ret = write_segment_descriptor(ctxt, selector, + &seg_desc); + if (ret != X86EMUL_CONTINUE) + return ret; + } + } else if (ctxt->mode == X86EMUL_MODE_PROT64) { + ret = linear_read_system(ctxt, desc_addr+8, &base3, sizeof(base3)); + if (ret != X86EMUL_CONTINUE) + return ret; + if (emul_is_noncanonical_address(get_desc_base(&seg_desc) | + ((u64)base3 << 32), ctxt)) + return emulate_gp(ctxt, 0); + } +load: + ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg); + if (desc) + *desc = seg_desc; + return X86EMUL_CONTINUE; +exception: + return emulate_exception(ctxt, err_vec, err_code, true); +} + +static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, + u16 selector, int seg) +{ + u8 cpl = ctxt->ops->cpl(ctxt); + + /* + * None of MOV, POP and LSS can load a NULL selector in CPL=3, but + * they can load it at CPL<3 (Intel's manual says only LSS can, + * but it's wrong). + * + * However, the Intel manual says that putting IST=1/DPL=3 in + * an interrupt gate will result in SS=3 (the AMD manual instead + * says it doesn't), so allow SS=3 in __load_segment_descriptor + * and only forbid it here. + */ + if (seg == VCPU_SREG_SS && selector == 3 && + ctxt->mode == X86EMUL_MODE_PROT64) + return emulate_exception(ctxt, GP_VECTOR, 0, true); + + return __load_segment_descriptor(ctxt, selector, seg, cpl, + X86_TRANSFER_NONE, NULL); +} + +static void write_register_operand(struct operand *op) +{ + return assign_register(op->addr.reg, op->val, op->bytes); +} + +static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op) +{ + switch (op->type) { + case OP_REG: + write_register_operand(op); + break; + case OP_MEM: + if (ctxt->lock_prefix) + return segmented_cmpxchg(ctxt, + op->addr.mem, + &op->orig_val, + &op->val, + op->bytes); + else + return segmented_write(ctxt, + op->addr.mem, + &op->val, + op->bytes); + break; + case OP_MEM_STR: + return segmented_write(ctxt, + op->addr.mem, + op->data, + op->bytes * op->count); + break; + case OP_XMM: + write_sse_reg(ctxt, &op->vec_val, op->addr.xmm); + break; + case OP_MM: + write_mmx_reg(ctxt, &op->mm_val, op->addr.mm); + break; + case OP_NONE: + /* no writeback */ + break; + default: + break; + } + return X86EMUL_CONTINUE; +} + +static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes) +{ + struct segmented_address addr; + + rsp_increment(ctxt, -bytes); + addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); + addr.seg = VCPU_SREG_SS; + + return segmented_write(ctxt, addr, data, bytes); +} + +static int em_push(struct x86_emulate_ctxt *ctxt) +{ + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return push(ctxt, &ctxt->src.val, ctxt->op_bytes); +} + +static int emulate_pop(struct x86_emulate_ctxt *ctxt, + void *dest, int len) +{ + int rc; + struct segmented_address addr; + + addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); + addr.seg = VCPU_SREG_SS; + rc = segmented_read(ctxt, addr, dest, len); + if (rc != X86EMUL_CONTINUE) + return rc; + + rsp_increment(ctxt, len); + return rc; +} + +static int em_pop(struct x86_emulate_ctxt *ctxt) +{ + return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); +} + +static int emulate_popf(struct x86_emulate_ctxt *ctxt, + void *dest, int len) +{ + int rc; + unsigned long val, change_mask; + int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; + int cpl = ctxt->ops->cpl(ctxt); + + rc = emulate_pop(ctxt, &val, len); + if (rc != X86EMUL_CONTINUE) + return rc; + + change_mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | + X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF | + X86_EFLAGS_TF | X86_EFLAGS_DF | X86_EFLAGS_NT | + X86_EFLAGS_AC | X86_EFLAGS_ID; + + switch(ctxt->mode) { + case X86EMUL_MODE_PROT64: + case X86EMUL_MODE_PROT32: + case X86EMUL_MODE_PROT16: + if (cpl == 0) + change_mask |= X86_EFLAGS_IOPL; + if (cpl <= iopl) + change_mask |= X86_EFLAGS_IF; + break; + case X86EMUL_MODE_VM86: + if (iopl < 3) + return emulate_gp(ctxt, 0); + change_mask |= X86_EFLAGS_IF; + break; + default: /* real mode */ + change_mask |= (X86_EFLAGS_IOPL | X86_EFLAGS_IF); + break; + } + + *(unsigned long *)dest = + (ctxt->eflags & ~change_mask) | (val & change_mask); + + return rc; +} + +static int em_popf(struct x86_emulate_ctxt *ctxt) +{ + ctxt->dst.type = OP_REG; + ctxt->dst.addr.reg = &ctxt->eflags; + ctxt->dst.bytes = ctxt->op_bytes; + return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes); +} + +static int em_enter(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned frame_size = ctxt->src.val; + unsigned nesting_level = ctxt->src2.val & 31; + ulong rbp; + + if (nesting_level) + return X86EMUL_UNHANDLEABLE; + + rbp = reg_read(ctxt, VCPU_REGS_RBP); + rc = push(ctxt, &rbp, stack_size(ctxt)); + if (rc != X86EMUL_CONTINUE) + return rc; + assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP), + stack_mask(ctxt)); + assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), + reg_read(ctxt, VCPU_REGS_RSP) - frame_size, + stack_mask(ctxt)); + return X86EMUL_CONTINUE; +} + +static int em_leave(struct x86_emulate_ctxt *ctxt) +{ + assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP), + stack_mask(ctxt)); + return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes); +} + +static int em_push_sreg(struct x86_emulate_ctxt *ctxt) +{ + int seg = ctxt->src2.val; + + ctxt->src.val = get_segment_selector(ctxt, seg); + if (ctxt->op_bytes == 4) { + rsp_increment(ctxt, -2); + ctxt->op_bytes = 2; + } + + return em_push(ctxt); +} + +static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) +{ + int seg = ctxt->src2.val; + unsigned long selector; + int rc; + + rc = emulate_pop(ctxt, &selector, 2); + if (rc != X86EMUL_CONTINUE) + return rc; + + if (ctxt->modrm_reg == VCPU_SREG_SS) + ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; + if (ctxt->op_bytes > 2) + rsp_increment(ctxt, ctxt->op_bytes - 2); + + rc = load_segment_descriptor(ctxt, (u16)selector, seg); + return rc; +} + +static int em_pusha(struct x86_emulate_ctxt *ctxt) +{ + unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP); + int rc = X86EMUL_CONTINUE; + int reg = VCPU_REGS_RAX; + + while (reg <= VCPU_REGS_RDI) { + (reg == VCPU_REGS_RSP) ? + (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg)); + + rc = em_push(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + ++reg; + } + + return rc; +} + +static int em_pushf(struct x86_emulate_ctxt *ctxt) +{ + ctxt->src.val = (unsigned long)ctxt->eflags & ~X86_EFLAGS_VM; + return em_push(ctxt); +} + +static int em_popa(struct x86_emulate_ctxt *ctxt) +{ + int rc = X86EMUL_CONTINUE; + int reg = VCPU_REGS_RDI; + u32 val; + + while (reg >= VCPU_REGS_RAX) { + if (reg == VCPU_REGS_RSP) { + rsp_increment(ctxt, ctxt->op_bytes); + --reg; + } + + rc = emulate_pop(ctxt, &val, ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + break; + assign_register(reg_rmw(ctxt, reg), val, ctxt->op_bytes); + --reg; + } + return rc; +} + +static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + int rc; + struct desc_ptr dt; + gva_t cs_addr; + gva_t eip_addr; + u16 cs, eip; + + /* TODO: Add limit checks */ + ctxt->src.val = ctxt->eflags; + rc = em_push(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + ctxt->eflags &= ~(X86_EFLAGS_IF | X86_EFLAGS_TF | X86_EFLAGS_AC); + + ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); + rc = em_push(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + ctxt->src.val = ctxt->_eip; + rc = em_push(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + ops->get_idt(ctxt, &dt); + + eip_addr = dt.address + (irq << 2); + cs_addr = dt.address + (irq << 2) + 2; + + rc = linear_read_system(ctxt, cs_addr, &cs, 2); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = linear_read_system(ctxt, eip_addr, &eip, 2); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS); + if (rc != X86EMUL_CONTINUE) + return rc; + + ctxt->_eip = eip; + + return rc; +} + +int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) +{ + int rc; + + invalidate_registers(ctxt); + rc = __emulate_int_real(ctxt, irq); + if (rc == X86EMUL_CONTINUE) + writeback_registers(ctxt); + return rc; +} + +static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq) +{ + switch(ctxt->mode) { + case X86EMUL_MODE_REAL: + return __emulate_int_real(ctxt, irq); + case X86EMUL_MODE_VM86: + case X86EMUL_MODE_PROT16: + case X86EMUL_MODE_PROT32: + case X86EMUL_MODE_PROT64: + default: + /* Protected mode interrupts unimplemented yet */ + return X86EMUL_UNHANDLEABLE; + } +} + +static int emulate_iret_real(struct x86_emulate_ctxt *ctxt) +{ + int rc = X86EMUL_CONTINUE; + unsigned long temp_eip = 0; + unsigned long temp_eflags = 0; + unsigned long cs = 0; + unsigned long mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | + X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_TF | + X86_EFLAGS_IF | X86_EFLAGS_DF | X86_EFLAGS_OF | + X86_EFLAGS_IOPL | X86_EFLAGS_NT | X86_EFLAGS_RF | + X86_EFLAGS_AC | X86_EFLAGS_ID | + X86_EFLAGS_FIXED; + unsigned long vm86_mask = X86_EFLAGS_VM | X86_EFLAGS_VIF | + X86_EFLAGS_VIP; + + /* TODO: Add stack limit check */ + + rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes); + + if (rc != X86EMUL_CONTINUE) + return rc; + + if (temp_eip & ~0xffff) + return emulate_gp(ctxt, 0); + + rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); + + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes); + + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS); + + if (rc != X86EMUL_CONTINUE) + return rc; + + ctxt->_eip = temp_eip; + + if (ctxt->op_bytes == 4) + ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask)); + else if (ctxt->op_bytes == 2) { + ctxt->eflags &= ~0xffff; + ctxt->eflags |= temp_eflags; + } + + ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */ + ctxt->eflags |= X86_EFLAGS_FIXED; + ctxt->ops->set_nmi_mask(ctxt, false); + + return rc; +} + +static int em_iret(struct x86_emulate_ctxt *ctxt) +{ + switch(ctxt->mode) { + case X86EMUL_MODE_REAL: + return emulate_iret_real(ctxt); + case X86EMUL_MODE_VM86: + case X86EMUL_MODE_PROT16: + case X86EMUL_MODE_PROT32: + case X86EMUL_MODE_PROT64: + default: + /* iret from protected mode unimplemented yet */ + return X86EMUL_UNHANDLEABLE; + } +} + +static int em_jmp_far(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned short sel; + struct desc_struct new_desc; + u8 cpl = ctxt->ops->cpl(ctxt); + + memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); + + rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, + X86_TRANSFER_CALL_JMP, + &new_desc); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); + /* Error handling is not implemented. */ + if (rc != X86EMUL_CONTINUE) + return X86EMUL_UNHANDLEABLE; + + return rc; +} + +static int em_jmp_abs(struct x86_emulate_ctxt *ctxt) +{ + return assign_eip_near(ctxt, ctxt->src.val); +} + +static int em_call_near_abs(struct x86_emulate_ctxt *ctxt) +{ + int rc; + long int old_eip; + + old_eip = ctxt->_eip; + rc = assign_eip_near(ctxt, ctxt->src.val); + if (rc != X86EMUL_CONTINUE) + return rc; + ctxt->src.val = old_eip; + rc = em_push(ctxt); + return rc; +} + +static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) +{ + u64 old = ctxt->dst.orig_val64; + + if (ctxt->dst.bytes == 16) + return X86EMUL_UNHANDLEABLE; + + if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || + ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { + *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); + *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32); + ctxt->eflags &= ~X86_EFLAGS_ZF; + } else { + ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) | + (u32) reg_read(ctxt, VCPU_REGS_RBX); + + ctxt->eflags |= X86_EFLAGS_ZF; + } + return X86EMUL_CONTINUE; +} + +static int em_ret(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned long eip; + + rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + return rc; + + return assign_eip_near(ctxt, eip); +} + +static int em_ret_far(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned long eip, cs; + int cpl = ctxt->ops->cpl(ctxt); + struct desc_struct new_desc; + + rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + return rc; + rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + return rc; + /* Outer-privilege level return is not implemented */ + if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl) + return X86EMUL_UNHANDLEABLE; + rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, cpl, + X86_TRANSFER_RET, + &new_desc); + if (rc != X86EMUL_CONTINUE) + return rc; + rc = assign_eip_far(ctxt, eip, &new_desc); + /* Error handling is not implemented. */ + if (rc != X86EMUL_CONTINUE) + return X86EMUL_UNHANDLEABLE; + + return rc; +} + +static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt) +{ + int rc; + + rc = em_ret_far(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + rsp_increment(ctxt, ctxt->src.val); + return X86EMUL_CONTINUE; +} + +static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) +{ + /* Save real source value, then compare EAX against destination. */ + ctxt->dst.orig_val = ctxt->dst.val; + ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX); + ctxt->src.orig_val = ctxt->src.val; + ctxt->src.val = ctxt->dst.orig_val; + fastop(ctxt, em_cmp); + + if (ctxt->eflags & X86_EFLAGS_ZF) { + /* Success: write back to memory; no update of EAX */ + ctxt->src.type = OP_NONE; + ctxt->dst.val = ctxt->src.orig_val; + } else { + /* Failure: write the value we saw to EAX. */ + ctxt->src.type = OP_REG; + ctxt->src.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); + ctxt->src.val = ctxt->dst.orig_val; + /* Create write-cycle to dest by writing the same value */ + ctxt->dst.val = ctxt->dst.orig_val; + } + return X86EMUL_CONTINUE; +} + +static int em_lseg(struct x86_emulate_ctxt *ctxt) +{ + int seg = ctxt->src2.val; + unsigned short sel; + int rc; + + memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); + + rc = load_segment_descriptor(ctxt, sel, seg); + if (rc != X86EMUL_CONTINUE) + return rc; + + ctxt->dst.val = ctxt->src.val; + return rc; +} + +static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt) +{ +#ifdef CONFIG_X86_64 + u32 eax, ebx, ecx, edx; + + eax = 0x80000001; + ecx = 0; + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); + return edx & bit(X86_FEATURE_LM); +#else + return false; +#endif +} + +#define GET_SMSTATE(type, smbase, offset) \ + ({ \ + type __val; \ + int r = ctxt->ops->read_phys(ctxt, smbase + offset, &__val, \ + sizeof(__val)); \ + if (r != X86EMUL_CONTINUE) \ + return X86EMUL_UNHANDLEABLE; \ + __val; \ + }) + +static void rsm_set_desc_flags(struct desc_struct *desc, u32 flags) +{ + desc->g = (flags >> 23) & 1; + desc->d = (flags >> 22) & 1; + desc->l = (flags >> 21) & 1; + desc->avl = (flags >> 20) & 1; + desc->p = (flags >> 15) & 1; + desc->dpl = (flags >> 13) & 3; + desc->s = (flags >> 12) & 1; + desc->type = (flags >> 8) & 15; +} + +static int rsm_load_seg_32(struct x86_emulate_ctxt *ctxt, u64 smbase, int n) +{ + struct desc_struct desc; + int offset; + u16 selector; + + selector = GET_SMSTATE(u32, smbase, 0x7fa8 + n * 4); + + if (n < 3) + offset = 0x7f84 + n * 12; + else + offset = 0x7f2c + (n - 3) * 12; + + set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8)); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4)); + rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, offset)); + ctxt->ops->set_segment(ctxt, selector, &desc, 0, n); + return X86EMUL_CONTINUE; +} + +#ifdef CONFIG_X86_64 +static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, u64 smbase, int n) +{ + struct desc_struct desc; + int offset; + u16 selector; + u32 base3; + + offset = 0x7e00 + n * 16; + + selector = GET_SMSTATE(u16, smbase, offset); + rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smbase, offset + 2) << 8); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4)); + set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8)); + base3 = GET_SMSTATE(u32, smbase, offset + 12); + + ctxt->ops->set_segment(ctxt, selector, &desc, base3, n); + return X86EMUL_CONTINUE; +} +#endif + +static int rsm_enter_protected_mode(struct x86_emulate_ctxt *ctxt, + u64 cr0, u64 cr3, u64 cr4) +{ + int bad; + u64 pcid; + + /* In order to later set CR4.PCIDE, CR3[11:0] must be zero. */ + pcid = 0; + if (cr4 & X86_CR4_PCIDE) { + pcid = cr3 & 0xfff; + cr3 &= ~0xfff; + } + + bad = ctxt->ops->set_cr(ctxt, 3, cr3); + if (bad) + return X86EMUL_UNHANDLEABLE; + + /* + * First enable PAE, long mode needs it before CR0.PG = 1 is set. + * Then enable protected mode. However, PCID cannot be enabled + * if EFER.LMA=0, so set it separately. + */ + bad = ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); + if (bad) + return X86EMUL_UNHANDLEABLE; + + bad = ctxt->ops->set_cr(ctxt, 0, cr0); + if (bad) + return X86EMUL_UNHANDLEABLE; + + if (cr4 & X86_CR4_PCIDE) { + bad = ctxt->ops->set_cr(ctxt, 4, cr4); + if (bad) + return X86EMUL_UNHANDLEABLE; + if (pcid) { + bad = ctxt->ops->set_cr(ctxt, 3, cr3 | pcid); + if (bad) + return X86EMUL_UNHANDLEABLE; + } + + } + + return X86EMUL_CONTINUE; +} + +static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, u64 smbase) +{ + struct desc_struct desc; + struct desc_ptr dt; + u16 selector; + u32 val, cr0, cr3, cr4; + int i; + + cr0 = GET_SMSTATE(u32, smbase, 0x7ffc); + cr3 = GET_SMSTATE(u32, smbase, 0x7ff8); + ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7ff4) | X86_EFLAGS_FIXED; + ctxt->_eip = GET_SMSTATE(u32, smbase, 0x7ff0); + + for (i = 0; i < 8; i++) + *reg_write(ctxt, i) = GET_SMSTATE(u32, smbase, 0x7fd0 + i * 4); + + val = GET_SMSTATE(u32, smbase, 0x7fcc); + ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1); + val = GET_SMSTATE(u32, smbase, 0x7fc8); + ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1); + + selector = GET_SMSTATE(u32, smbase, 0x7fc4); + set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f64)); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f60)); + rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f5c)); + ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_TR); + + selector = GET_SMSTATE(u32, smbase, 0x7fc0); + set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f80)); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f7c)); + rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f78)); + ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_LDTR); + + dt.address = GET_SMSTATE(u32, smbase, 0x7f74); + dt.size = GET_SMSTATE(u32, smbase, 0x7f70); + ctxt->ops->set_gdt(ctxt, &dt); + + dt.address = GET_SMSTATE(u32, smbase, 0x7f58); + dt.size = GET_SMSTATE(u32, smbase, 0x7f54); + ctxt->ops->set_idt(ctxt, &dt); + + for (i = 0; i < 6; i++) { + int r = rsm_load_seg_32(ctxt, smbase, i); + if (r != X86EMUL_CONTINUE) + return r; + } + + cr4 = GET_SMSTATE(u32, smbase, 0x7f14); + + ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7ef8)); + + return rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); +} + +#ifdef CONFIG_X86_64 +static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase) +{ + struct desc_struct desc; + struct desc_ptr dt; + u64 val, cr0, cr3, cr4; + u32 base3; + u16 selector; + int i, r; + + for (i = 0; i < 16; i++) + *reg_write(ctxt, i) = GET_SMSTATE(u64, smbase, 0x7ff8 - i * 8); + + ctxt->_eip = GET_SMSTATE(u64, smbase, 0x7f78); + ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7f70) | X86_EFLAGS_FIXED; + + val = GET_SMSTATE(u32, smbase, 0x7f68); + ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1); + val = GET_SMSTATE(u32, smbase, 0x7f60); + ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1); + + cr0 = GET_SMSTATE(u64, smbase, 0x7f58); + cr3 = GET_SMSTATE(u64, smbase, 0x7f50); + cr4 = GET_SMSTATE(u64, smbase, 0x7f48); + ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7f00)); + val = GET_SMSTATE(u64, smbase, 0x7ed0); + ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA); + + selector = GET_SMSTATE(u32, smbase, 0x7e90); + rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e92) << 8); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e94)); + set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e98)); + base3 = GET_SMSTATE(u32, smbase, 0x7e9c); + ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR); + + dt.size = GET_SMSTATE(u32, smbase, 0x7e84); + dt.address = GET_SMSTATE(u64, smbase, 0x7e88); + ctxt->ops->set_idt(ctxt, &dt); + + selector = GET_SMSTATE(u32, smbase, 0x7e70); + rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e72) << 8); + set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e74)); + set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e78)); + base3 = GET_SMSTATE(u32, smbase, 0x7e7c); + ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR); + + dt.size = GET_SMSTATE(u32, smbase, 0x7e64); + dt.address = GET_SMSTATE(u64, smbase, 0x7e68); + ctxt->ops->set_gdt(ctxt, &dt); + + r = rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); + if (r != X86EMUL_CONTINUE) + return r; + + for (i = 0; i < 6; i++) { + r = rsm_load_seg_64(ctxt, smbase, i); + if (r != X86EMUL_CONTINUE) + return r; + } + + return X86EMUL_CONTINUE; +} +#endif + +static int em_rsm(struct x86_emulate_ctxt *ctxt) +{ + unsigned long cr0, cr4, efer; + u64 smbase; + int ret; + + if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_MASK) == 0) + return emulate_ud(ctxt); + + /* + * Get back to real mode, to prepare a safe state in which to load + * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU + * supports long mode. + */ + if (emulator_has_longmode(ctxt)) { + struct desc_struct cs_desc; + + /* Zero CR4.PCIDE before CR0.PG. */ + cr4 = ctxt->ops->get_cr(ctxt, 4); + if (cr4 & X86_CR4_PCIDE) + ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); + + /* A 32-bit code segment is required to clear EFER.LMA. */ + memset(&cs_desc, 0, sizeof(cs_desc)); + cs_desc.type = 0xb; + cs_desc.s = cs_desc.g = cs_desc.p = 1; + ctxt->ops->set_segment(ctxt, 0, &cs_desc, 0, VCPU_SREG_CS); + } + + /* For the 64-bit case, this will clear EFER.LMA. */ + cr0 = ctxt->ops->get_cr(ctxt, 0); + if (cr0 & X86_CR0_PE) + ctxt->ops->set_cr(ctxt, 0, cr0 & ~(X86_CR0_PG | X86_CR0_PE)); + + if (emulator_has_longmode(ctxt)) { + /* Clear CR4.PAE before clearing EFER.LME. */ + cr4 = ctxt->ops->get_cr(ctxt, 4); + if (cr4 & X86_CR4_PAE) + ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PAE); + + /* And finally go back to 32-bit mode. */ + efer = 0; + ctxt->ops->set_msr(ctxt, MSR_EFER, efer); + } + + smbase = ctxt->ops->get_smbase(ctxt); + + /* + * Give pre_leave_smm() a chance to make ISA-specific changes to the + * vCPU state (e.g. enter guest mode) before loading state from the SMM + * state-save area. + */ + if (ctxt->ops->pre_leave_smm(ctxt, smbase)) + return X86EMUL_UNHANDLEABLE; + +#ifdef CONFIG_X86_64 + if (emulator_has_longmode(ctxt)) + ret = rsm_load_state_64(ctxt, smbase + 0x8000); + else +#endif + ret = rsm_load_state_32(ctxt, smbase + 0x8000); + + if (ret != X86EMUL_CONTINUE) { + /* FIXME: should triple fault */ + return X86EMUL_UNHANDLEABLE; + } + + if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0) + ctxt->ops->set_nmi_mask(ctxt, false); + + ctxt->ops->set_hflags(ctxt, ctxt->ops->get_hflags(ctxt) & + ~(X86EMUL_SMM_INSIDE_NMI_MASK | X86EMUL_SMM_MASK)); + return X86EMUL_CONTINUE; +} + +static void +setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, + struct desc_struct *cs, struct desc_struct *ss) +{ + cs->l = 0; /* will be adjusted later */ + set_desc_base(cs, 0); /* flat segment */ + cs->g = 1; /* 4kb granularity */ + set_desc_limit(cs, 0xfffff); /* 4GB limit */ + cs->type = 0x0b; /* Read, Execute, Accessed */ + cs->s = 1; + cs->dpl = 0; /* will be adjusted later */ + cs->p = 1; + cs->d = 1; + cs->avl = 0; + + set_desc_base(ss, 0); /* flat segment */ + set_desc_limit(ss, 0xfffff); /* 4GB limit */ + ss->g = 1; /* 4kb granularity */ + ss->s = 1; + ss->type = 0x03; /* Read/Write, Accessed */ + ss->d = 1; /* 32bit stack segment */ + ss->dpl = 0; + ss->p = 1; + ss->l = 0; + ss->avl = 0; +} + +static bool vendor_intel(struct x86_emulate_ctxt *ctxt) +{ + u32 eax, ebx, ecx, edx; + + eax = ecx = 0; + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); + return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx + && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx + && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx; +} + +static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + u32 eax, ebx, ecx, edx; + + /* + * syscall should always be enabled in longmode - so only become + * vendor specific (cpuid) if other modes are active... + */ + if (ctxt->mode == X86EMUL_MODE_PROT64) + return true; + + eax = 0x00000000; + ecx = 0x00000000; + ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); + /* + * Intel ("GenuineIntel") + * remark: Intel CPUs only support "syscall" in 64bit + * longmode. Also an 64bit guest with a + * 32bit compat-app running will #UD !! While this + * behaviour can be fixed (by emulating) into AMD + * response - CPUs of AMD can't behave like Intel. + */ + if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && + ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && + edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx) + return false; + + /* AMD ("AuthenticAMD") */ + if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx && + ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx && + edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx) + return true; + + /* AMD ("AMDisbetter!") */ + if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx && + ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx && + edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx) + return true; + + /* default: (not Intel, not AMD), apply Intel's stricter rules... */ + return false; +} + +static int em_syscall(struct x86_emulate_ctxt *ctxt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + struct desc_struct cs, ss; + u64 msr_data; + u16 cs_sel, ss_sel; + u64 efer = 0; + + /* syscall is not available in real mode */ + if (ctxt->mode == X86EMUL_MODE_REAL || + ctxt->mode == X86EMUL_MODE_VM86) + return emulate_ud(ctxt); + + if (!(em_syscall_is_enabled(ctxt))) + return emulate_ud(ctxt); + + ops->get_msr(ctxt, MSR_EFER, &efer); + setup_syscalls_segments(ctxt, &cs, &ss); + + if (!(efer & EFER_SCE)) + return emulate_ud(ctxt); + + ops->get_msr(ctxt, MSR_STAR, &msr_data); + msr_data >>= 32; + cs_sel = (u16)(msr_data & 0xfffc); + ss_sel = (u16)(msr_data + 8); + + if (efer & EFER_LMA) { + cs.d = 0; + cs.l = 1; + } + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); + + *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip; + if (efer & EFER_LMA) { +#ifdef CONFIG_X86_64 + *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags; + + ops->get_msr(ctxt, + ctxt->mode == X86EMUL_MODE_PROT64 ? + MSR_LSTAR : MSR_CSTAR, &msr_data); + ctxt->_eip = msr_data; + + ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); + ctxt->eflags &= ~msr_data; + ctxt->eflags |= X86_EFLAGS_FIXED; +#endif + } else { + /* legacy mode */ + ops->get_msr(ctxt, MSR_STAR, &msr_data); + ctxt->_eip = (u32)msr_data; + + ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); + } + + ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0; + return X86EMUL_CONTINUE; +} + +static int em_sysenter(struct x86_emulate_ctxt *ctxt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + struct desc_struct cs, ss; + u64 msr_data; + u16 cs_sel, ss_sel; + u64 efer = 0; + + ops->get_msr(ctxt, MSR_EFER, &efer); + /* inject #GP if in real mode */ + if (ctxt->mode == X86EMUL_MODE_REAL) + return emulate_gp(ctxt, 0); + + /* + * Not recognized on AMD in compat mode (but is recognized in legacy + * mode). + */ + if ((ctxt->mode != X86EMUL_MODE_PROT64) && (efer & EFER_LMA) + && !vendor_intel(ctxt)) + return emulate_ud(ctxt); + + /* sysenter/sysexit have not been tested in 64bit mode. */ + if (ctxt->mode == X86EMUL_MODE_PROT64) + return X86EMUL_UNHANDLEABLE; + + setup_syscalls_segments(ctxt, &cs, &ss); + + ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); + if ((msr_data & 0xfffc) == 0x0) + return emulate_gp(ctxt, 0); + + ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); + cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK; + ss_sel = cs_sel + 8; + if (efer & EFER_LMA) { + cs.d = 0; + cs.l = 1; + } + + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); + + ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); + ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data; + + ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); + *reg_write(ctxt, VCPU_REGS_RSP) = (efer & EFER_LMA) ? msr_data : + (u32)msr_data; + + return X86EMUL_CONTINUE; +} + +static int em_sysexit(struct x86_emulate_ctxt *ctxt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + struct desc_struct cs, ss; + u64 msr_data, rcx, rdx; + int usermode; + u16 cs_sel = 0, ss_sel = 0; + + /* inject #GP if in real mode or Virtual 8086 mode */ + if (ctxt->mode == X86EMUL_MODE_REAL || + ctxt->mode == X86EMUL_MODE_VM86) + return emulate_gp(ctxt, 0); + + setup_syscalls_segments(ctxt, &cs, &ss); + + if ((ctxt->rex_prefix & 0x8) != 0x0) + usermode = X86EMUL_MODE_PROT64; + else + usermode = X86EMUL_MODE_PROT32; + + rcx = reg_read(ctxt, VCPU_REGS_RCX); + rdx = reg_read(ctxt, VCPU_REGS_RDX); + + cs.dpl = 3; + ss.dpl = 3; + ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); + switch (usermode) { + case X86EMUL_MODE_PROT32: + cs_sel = (u16)(msr_data + 16); + if ((msr_data & 0xfffc) == 0x0) + return emulate_gp(ctxt, 0); + ss_sel = (u16)(msr_data + 24); + rcx = (u32)rcx; + rdx = (u32)rdx; + break; + case X86EMUL_MODE_PROT64: + cs_sel = (u16)(msr_data + 32); + if (msr_data == 0x0) + return emulate_gp(ctxt, 0); + ss_sel = cs_sel + 8; + cs.d = 0; + cs.l = 1; + if (emul_is_noncanonical_address(rcx, ctxt) || + emul_is_noncanonical_address(rdx, ctxt)) + return emulate_gp(ctxt, 0); + break; + } + cs_sel |= SEGMENT_RPL_MASK; + ss_sel |= SEGMENT_RPL_MASK; + + ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); + ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); + + ctxt->_eip = rdx; + *reg_write(ctxt, VCPU_REGS_RSP) = rcx; + + return X86EMUL_CONTINUE; +} + +static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt) +{ + int iopl; + if (ctxt->mode == X86EMUL_MODE_REAL) + return false; + if (ctxt->mode == X86EMUL_MODE_VM86) + return true; + iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; + return ctxt->ops->cpl(ctxt) > iopl; +} + +#define VMWARE_PORT_VMPORT (0x5658) +#define VMWARE_PORT_VMRPC (0x5659) + +static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, + u16 port, u16 len) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + struct desc_struct tr_seg; + u32 base3; + int r; + u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; + unsigned mask = (1 << len) - 1; + unsigned long base; + + /* + * VMware allows access to these ports even if denied + * by TSS I/O permission bitmap. Mimic behavior. + */ + if (enable_vmware_backdoor && + ((port == VMWARE_PORT_VMPORT) || (port == VMWARE_PORT_VMRPC))) + return true; + + ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); + if (!tr_seg.p) + return false; + if (desc_limit_scaled(&tr_seg) < 103) + return false; + base = get_desc_base(&tr_seg); +#ifdef CONFIG_X86_64 + base |= ((u64)base3) << 32; +#endif + r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL, true); + if (r != X86EMUL_CONTINUE) + return false; + if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) + return false; + r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL, true); + if (r != X86EMUL_CONTINUE) + return false; + if ((perm >> bit_idx) & mask) + return false; + return true; +} + +static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, + u16 port, u16 len) +{ + if (ctxt->perm_ok) + return true; + + if (emulator_bad_iopl(ctxt)) + if (!emulator_io_port_access_allowed(ctxt, port, len)) + return false; + + ctxt->perm_ok = true; + + return true; +} + +static void string_registers_quirk(struct x86_emulate_ctxt *ctxt) +{ + /* + * Intel CPUs mask the counter and pointers in quite strange + * manner when ECX is zero due to REP-string optimizations. + */ +#ifdef CONFIG_X86_64 + if (ctxt->ad_bytes != 4 || !vendor_intel(ctxt)) + return; + + *reg_write(ctxt, VCPU_REGS_RCX) = 0; + + switch (ctxt->b) { + case 0xa4: /* movsb */ + case 0xa5: /* movsd/w */ + *reg_rmw(ctxt, VCPU_REGS_RSI) &= (u32)-1; + /* fall through */ + case 0xaa: /* stosb */ + case 0xab: /* stosd/w */ + *reg_rmw(ctxt, VCPU_REGS_RDI) &= (u32)-1; + } +#endif +} + +static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, + struct tss_segment_16 *tss) +{ + tss->ip = ctxt->_eip; + tss->flag = ctxt->eflags; + tss->ax = reg_read(ctxt, VCPU_REGS_RAX); + tss->cx = reg_read(ctxt, VCPU_REGS_RCX); + tss->dx = reg_read(ctxt, VCPU_REGS_RDX); + tss->bx = reg_read(ctxt, VCPU_REGS_RBX); + tss->sp = reg_read(ctxt, VCPU_REGS_RSP); + tss->bp = reg_read(ctxt, VCPU_REGS_RBP); + tss->si = reg_read(ctxt, VCPU_REGS_RSI); + tss->di = reg_read(ctxt, VCPU_REGS_RDI); + + tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); + tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); + tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); + tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); + tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); +} + +static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, + struct tss_segment_16 *tss) +{ + int ret; + u8 cpl; + + ctxt->_eip = tss->ip; + ctxt->eflags = tss->flag | 2; + *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax; + *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx; + *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx; + *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx; + *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp; + *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp; + *reg_write(ctxt, VCPU_REGS_RSI) = tss->si; + *reg_write(ctxt, VCPU_REGS_RDI) = tss->di; + + /* + * SDM says that segment selectors are loaded before segment + * descriptors + */ + set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); + set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); + set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); + set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); + set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); + + cpl = tss->cs & 3; + + /* + * Now load segment descriptors. If fault happens at this stage + * it is handled in a context of new task + */ + ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + + return X86EMUL_CONTINUE; +} + +static int task_switch_16(struct x86_emulate_ctxt *ctxt, + u16 tss_selector, u16 old_tss_sel, + ulong old_tss_base, struct desc_struct *new_desc) +{ + struct tss_segment_16 tss_seg; + int ret; + u32 new_tss_base = get_desc_base(new_desc); + + ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg); + if (ret != X86EMUL_CONTINUE) + return ret; + + save_state_to_tss16(ctxt, &tss_seg); + + ret = linear_write_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg); + if (ret != X86EMUL_CONTINUE) + return ret; + + ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg); + if (ret != X86EMUL_CONTINUE) + return ret; + + if (old_tss_sel != 0xffff) { + tss_seg.prev_task_link = old_tss_sel; + + ret = linear_write_system(ctxt, new_tss_base, + &tss_seg.prev_task_link, + sizeof tss_seg.prev_task_link); + if (ret != X86EMUL_CONTINUE) + return ret; + } + + return load_state_from_tss16(ctxt, &tss_seg); +} + +static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, + struct tss_segment_32 *tss) +{ + /* CR3 and ldt selector are not saved intentionally */ + tss->eip = ctxt->_eip; + tss->eflags = ctxt->eflags; + tss->eax = reg_read(ctxt, VCPU_REGS_RAX); + tss->ecx = reg_read(ctxt, VCPU_REGS_RCX); + tss->edx = reg_read(ctxt, VCPU_REGS_RDX); + tss->ebx = reg_read(ctxt, VCPU_REGS_RBX); + tss->esp = reg_read(ctxt, VCPU_REGS_RSP); + tss->ebp = reg_read(ctxt, VCPU_REGS_RBP); + tss->esi = reg_read(ctxt, VCPU_REGS_RSI); + tss->edi = reg_read(ctxt, VCPU_REGS_RDI); + + tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); + tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); + tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); + tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); + tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); + tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); +} + +static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, + struct tss_segment_32 *tss) +{ + int ret; + u8 cpl; + + if (ctxt->ops->set_cr(ctxt, 3, tss->cr3)) + return emulate_gp(ctxt, 0); + ctxt->_eip = tss->eip; + ctxt->eflags = tss->eflags | 2; + + /* General purpose registers */ + *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax; + *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx; + *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx; + *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx; + *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp; + *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp; + *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi; + *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi; + + /* + * SDM says that segment selectors are loaded before segment + * descriptors. This is important because CPL checks will + * use CS.RPL. + */ + set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); + set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); + set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); + set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); + set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); + set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); + set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); + + /* + * If we're switching between Protected Mode and VM86, we need to make + * sure to update the mode before loading the segment descriptors so + * that the selectors are interpreted correctly. + */ + if (ctxt->eflags & X86_EFLAGS_VM) { + ctxt->mode = X86EMUL_MODE_VM86; + cpl = 3; + } else { + ctxt->mode = X86EMUL_MODE_PROT32; + cpl = tss->cs & 3; + } + + /* + * Now load segment descriptors. If fault happenes at this stage + * it is handled in a context of new task + */ + ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR, + cpl, X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl, + X86_TRANSFER_TASK_SWITCH, NULL); + + return ret; +} + +static int task_switch_32(struct x86_emulate_ctxt *ctxt, + u16 tss_selector, u16 old_tss_sel, + ulong old_tss_base, struct desc_struct *new_desc) +{ + struct tss_segment_32 tss_seg; + int ret; + u32 new_tss_base = get_desc_base(new_desc); + u32 eip_offset = offsetof(struct tss_segment_32, eip); + u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector); + + ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof tss_seg); + if (ret != X86EMUL_CONTINUE) + return ret; + + save_state_to_tss32(ctxt, &tss_seg); + + /* Only GP registers and segment selectors are saved */ + ret = linear_write_system(ctxt, old_tss_base + eip_offset, &tss_seg.eip, + ldt_sel_offset - eip_offset); + if (ret != X86EMUL_CONTINUE) + return ret; + + ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof tss_seg); + if (ret != X86EMUL_CONTINUE) + return ret; + + if (old_tss_sel != 0xffff) { + tss_seg.prev_task_link = old_tss_sel; + + ret = linear_write_system(ctxt, new_tss_base, + &tss_seg.prev_task_link, + sizeof tss_seg.prev_task_link); + if (ret != X86EMUL_CONTINUE) + return ret; + } + + return load_state_from_tss32(ctxt, &tss_seg); +} + +static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, + u16 tss_selector, int idt_index, int reason, + bool has_error_code, u32 error_code) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + struct desc_struct curr_tss_desc, next_tss_desc; + int ret; + u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); + ulong old_tss_base = + ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); + u32 desc_limit; + ulong desc_addr, dr7; + + /* FIXME: old_tss_base == ~0 ? */ + + ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr); + if (ret != X86EMUL_CONTINUE) + return ret; + ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr); + if (ret != X86EMUL_CONTINUE) + return ret; + + /* FIXME: check that next_tss_desc is tss */ + + /* + * Check privileges. The three cases are task switch caused by... + * + * 1. jmp/call/int to task gate: Check against DPL of the task gate + * 2. Exception/IRQ/iret: No check is performed + * 3. jmp/call to TSS/task-gate: No check is performed since the + * hardware checks it before exiting. + */ + if (reason == TASK_SWITCH_GATE) { + if (idt_index != -1) { + /* Software interrupts */ + struct desc_struct task_gate_desc; + int dpl; + + ret = read_interrupt_descriptor(ctxt, idt_index, + &task_gate_desc); + if (ret != X86EMUL_CONTINUE) + return ret; + + dpl = task_gate_desc.dpl; + if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl) + return emulate_gp(ctxt, (idt_index << 3) | 0x2); + } + } + + desc_limit = desc_limit_scaled(&next_tss_desc); + if (!next_tss_desc.p || + ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || + desc_limit < 0x2b)) { + return emulate_ts(ctxt, tss_selector & 0xfffc); + } + + if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { + curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ + write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc); + } + + if (reason == TASK_SWITCH_IRET) + ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; + + /* set back link to prev task only if NT bit is set in eflags + note that old_tss_sel is not used after this point */ + if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) + old_tss_sel = 0xffff; + + if (next_tss_desc.type & 8) + ret = task_switch_32(ctxt, tss_selector, old_tss_sel, + old_tss_base, &next_tss_desc); + else + ret = task_switch_16(ctxt, tss_selector, old_tss_sel, + old_tss_base, &next_tss_desc); + if (ret != X86EMUL_CONTINUE) + return ret; + + if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) + ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; + + if (reason != TASK_SWITCH_IRET) { + next_tss_desc.type |= (1 << 1); /* set busy flag */ + write_segment_descriptor(ctxt, tss_selector, &next_tss_desc); + } + + ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); + ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); + + if (has_error_code) { + ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; + ctxt->lock_prefix = 0; + ctxt->src.val = (unsigned long) error_code; + ret = em_push(ctxt); + } + + ops->get_dr(ctxt, 7, &dr7); + ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN)); + + return ret; +} + +int emulator_task_switch(struct x86_emulate_ctxt *ctxt, + u16 tss_selector, int idt_index, int reason, + bool has_error_code, u32 error_code) +{ + int rc; + + invalidate_registers(ctxt); + ctxt->_eip = ctxt->eip; + ctxt->dst.type = OP_NONE; + + rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason, + has_error_code, error_code); + + if (rc == X86EMUL_CONTINUE) { + ctxt->eip = ctxt->_eip; + writeback_registers(ctxt); + } + + return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; +} + +static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg, + struct operand *op) +{ + int df = (ctxt->eflags & X86_EFLAGS_DF) ? -op->count : op->count; + + register_address_increment(ctxt, reg, df * op->bytes); + op->addr.mem.ea = register_address(ctxt, reg); +} + +static int em_das(struct x86_emulate_ctxt *ctxt) +{ + u8 al, old_al; + bool af, cf, old_cf; + + cf = ctxt->eflags & X86_EFLAGS_CF; + al = ctxt->dst.val; + + old_al = al; + old_cf = cf; + cf = false; + af = ctxt->eflags & X86_EFLAGS_AF; + if ((al & 0x0f) > 9 || af) { + al -= 6; + cf = old_cf | (al >= 250); + af = true; + } else { + af = false; + } + if (old_al > 0x99 || old_cf) { + al -= 0x60; + cf = true; + } + + ctxt->dst.val = al; + /* Set PF, ZF, SF */ + ctxt->src.type = OP_IMM; + ctxt->src.val = 0; + ctxt->src.bytes = 1; + fastop(ctxt, em_or); + ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); + if (cf) + ctxt->eflags |= X86_EFLAGS_CF; + if (af) + ctxt->eflags |= X86_EFLAGS_AF; + return X86EMUL_CONTINUE; +} + +static int em_aam(struct x86_emulate_ctxt *ctxt) +{ + u8 al, ah; + + if (ctxt->src.val == 0) + return emulate_de(ctxt); + + al = ctxt->dst.val & 0xff; + ah = al / ctxt->src.val; + al %= ctxt->src.val; + + ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8); + + /* Set PF, ZF, SF */ + ctxt->src.type = OP_IMM; + ctxt->src.val = 0; + ctxt->src.bytes = 1; + fastop(ctxt, em_or); + + return X86EMUL_CONTINUE; +} + +static int em_aad(struct x86_emulate_ctxt *ctxt) +{ + u8 al = ctxt->dst.val & 0xff; + u8 ah = (ctxt->dst.val >> 8) & 0xff; + + al = (al + (ah * ctxt->src.val)) & 0xff; + + ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al; + + /* Set PF, ZF, SF */ + ctxt->src.type = OP_IMM; + ctxt->src.val = 0; + ctxt->src.bytes = 1; + fastop(ctxt, em_or); + + return X86EMUL_CONTINUE; +} + +static int em_call(struct x86_emulate_ctxt *ctxt) +{ + int rc; + long rel = ctxt->src.val; + + ctxt->src.val = (unsigned long)ctxt->_eip; + rc = jmp_rel(ctxt, rel); + if (rc != X86EMUL_CONTINUE) + return rc; + return em_push(ctxt); +} + +static int em_call_far(struct x86_emulate_ctxt *ctxt) +{ + u16 sel, old_cs; + ulong old_eip; + int rc; + struct desc_struct old_desc, new_desc; + const struct x86_emulate_ops *ops = ctxt->ops; + int cpl = ctxt->ops->cpl(ctxt); + enum x86emul_mode prev_mode = ctxt->mode; + + old_eip = ctxt->_eip; + ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS); + + memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); + rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, + X86_TRANSFER_CALL_JMP, &new_desc); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); + if (rc != X86EMUL_CONTINUE) + goto fail; + + ctxt->src.val = old_cs; + rc = em_push(ctxt); + if (rc != X86EMUL_CONTINUE) + goto fail; + + ctxt->src.val = old_eip; + rc = em_push(ctxt); + /* If we failed, we tainted the memory, but the very least we should + restore cs */ + if (rc != X86EMUL_CONTINUE) { + pr_warn_once("faulting far call emulation tainted memory\n"); + goto fail; + } + return rc; +fail: + ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS); + ctxt->mode = prev_mode; + return rc; + +} + +static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) +{ + int rc; + unsigned long eip; + + rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + return rc; + rc = assign_eip_near(ctxt, eip); + if (rc != X86EMUL_CONTINUE) + return rc; + rsp_increment(ctxt, ctxt->src.val); + return X86EMUL_CONTINUE; +} + +static int em_xchg(struct x86_emulate_ctxt *ctxt) +{ + /* Write back the register source. */ + ctxt->src.val = ctxt->dst.val; + write_register_operand(&ctxt->src); + + /* Write back the memory destination with implicit LOCK prefix. */ + ctxt->dst.val = ctxt->src.orig_val; + ctxt->lock_prefix = 1; + return X86EMUL_CONTINUE; +} + +static int em_imul_3op(struct x86_emulate_ctxt *ctxt) +{ + ctxt->dst.val = ctxt->src2.val; + return fastop(ctxt, em_imul); +} + +static int em_cwd(struct x86_emulate_ctxt *ctxt) +{ + ctxt->dst.type = OP_REG; + ctxt->dst.bytes = ctxt->src.bytes; + ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); + ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1); + + return X86EMUL_CONTINUE; +} + +static int em_rdpid(struct x86_emulate_ctxt *ctxt) +{ + u64 tsc_aux = 0; + + if (ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux)) + return emulate_ud(ctxt); + ctxt->dst.val = tsc_aux; + return X86EMUL_CONTINUE; +} + +static int em_rdtsc(struct x86_emulate_ctxt *ctxt) +{ + u64 tsc = 0; + + ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc; + *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32; + return X86EMUL_CONTINUE; +} + +static int em_rdpmc(struct x86_emulate_ctxt *ctxt) +{ + u64 pmc; + + if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc)) + return emulate_gp(ctxt, 0); + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc; + *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32; + return X86EMUL_CONTINUE; +} + +static int em_mov(struct x86_emulate_ctxt *ctxt) +{ + memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr)); + return X86EMUL_CONTINUE; +} + +#define FFL(x) bit(X86_FEATURE_##x) + +static int em_movbe(struct x86_emulate_ctxt *ctxt) +{ + u32 ebx, ecx, edx, eax = 1; + u16 tmp; + + /* + * Check MOVBE is set in the guest-visible CPUID leaf. + */ + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); + if (!(ecx & FFL(MOVBE))) + return emulate_ud(ctxt); + + switch (ctxt->op_bytes) { + case 2: + /* + * From MOVBE definition: "...When the operand size is 16 bits, + * the upper word of the destination register remains unchanged + * ..." + * + * Both casting ->valptr and ->val to u16 breaks strict aliasing + * rules so we have to do the operation almost per hand. + */ + tmp = (u16)ctxt->src.val; + ctxt->dst.val &= ~0xffffUL; + ctxt->dst.val |= (unsigned long)swab16(tmp); + break; + case 4: + ctxt->dst.val = swab32((u32)ctxt->src.val); + break; + case 8: + ctxt->dst.val = swab64(ctxt->src.val); + break; + default: + BUG(); + } + return X86EMUL_CONTINUE; +} + +static int em_cr_write(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val)) + return emulate_gp(ctxt, 0); + + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_dr_write(struct x86_emulate_ctxt *ctxt) +{ + unsigned long val; + + if (ctxt->mode == X86EMUL_MODE_PROT64) + val = ctxt->src.val & ~0ULL; + else + val = ctxt->src.val & ~0U; + + /* #UD condition is already handled. */ + if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0) + return emulate_gp(ctxt, 0); + + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_wrmsr(struct x86_emulate_ctxt *ctxt) +{ + u64 msr_data; + + msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) + | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); + if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data)) + return emulate_gp(ctxt, 0); + + return X86EMUL_CONTINUE; +} + +static int em_rdmsr(struct x86_emulate_ctxt *ctxt) +{ + u64 msr_data; + + if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data)) + return emulate_gp(ctxt, 0); + + *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data; + *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32; + return X86EMUL_CONTINUE; +} + +static int em_store_sreg(struct x86_emulate_ctxt *ctxt, int segment) +{ + if (segment > VCPU_SREG_GS && + (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && + ctxt->ops->cpl(ctxt) > 0) + return emulate_gp(ctxt, 0); + + ctxt->dst.val = get_segment_selector(ctxt, segment); + if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM) + ctxt->dst.bytes = 2; + return X86EMUL_CONTINUE; +} + +static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->modrm_reg > VCPU_SREG_GS) + return emulate_ud(ctxt); + + return em_store_sreg(ctxt, ctxt->modrm_reg); +} + +static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt) +{ + u16 sel = ctxt->src.val; + + if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS) + return emulate_ud(ctxt); + + if (ctxt->modrm_reg == VCPU_SREG_SS) + ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; + + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg); +} + +static int em_sldt(struct x86_emulate_ctxt *ctxt) +{ + return em_store_sreg(ctxt, VCPU_SREG_LDTR); +} + +static int em_lldt(struct x86_emulate_ctxt *ctxt) +{ + u16 sel = ctxt->src.val; + + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR); +} + +static int em_str(struct x86_emulate_ctxt *ctxt) +{ + return em_store_sreg(ctxt, VCPU_SREG_TR); +} + +static int em_ltr(struct x86_emulate_ctxt *ctxt) +{ + u16 sel = ctxt->src.val; + + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR); +} + +static int em_invlpg(struct x86_emulate_ctxt *ctxt) +{ + int rc; + ulong linear; + + rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear); + if (rc == X86EMUL_CONTINUE) + ctxt->ops->invlpg(ctxt, linear); + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_clts(struct x86_emulate_ctxt *ctxt) +{ + ulong cr0; + + cr0 = ctxt->ops->get_cr(ctxt, 0); + cr0 &= ~X86_CR0_TS; + ctxt->ops->set_cr(ctxt, 0, cr0); + return X86EMUL_CONTINUE; +} + +static int em_hypercall(struct x86_emulate_ctxt *ctxt) +{ + int rc = ctxt->ops->fix_hypercall(ctxt); + + if (rc != X86EMUL_CONTINUE) + return rc; + + /* Let the processor re-execute the fixed hypercall */ + ctxt->_eip = ctxt->eip; + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt, + void (*get)(struct x86_emulate_ctxt *ctxt, + struct desc_ptr *ptr)) +{ + struct desc_ptr desc_ptr; + + if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && + ctxt->ops->cpl(ctxt) > 0) + return emulate_gp(ctxt, 0); + + if (ctxt->mode == X86EMUL_MODE_PROT64) + ctxt->op_bytes = 8; + get(ctxt, &desc_ptr); + if (ctxt->op_bytes == 2) { + ctxt->op_bytes = 4; + desc_ptr.address &= 0x00ffffff; + } + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return segmented_write_std(ctxt, ctxt->dst.addr.mem, + &desc_ptr, 2 + ctxt->op_bytes); +} + +static int em_sgdt(struct x86_emulate_ctxt *ctxt) +{ + return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt); +} + +static int em_sidt(struct x86_emulate_ctxt *ctxt) +{ + return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt); +} + +static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt) +{ + struct desc_ptr desc_ptr; + int rc; + + if (ctxt->mode == X86EMUL_MODE_PROT64) + ctxt->op_bytes = 8; + rc = read_descriptor(ctxt, ctxt->src.addr.mem, + &desc_ptr.size, &desc_ptr.address, + ctxt->op_bytes); + if (rc != X86EMUL_CONTINUE) + return rc; + if (ctxt->mode == X86EMUL_MODE_PROT64 && + emul_is_noncanonical_address(desc_ptr.address, ctxt)) + return emulate_gp(ctxt, 0); + if (lgdt) + ctxt->ops->set_gdt(ctxt, &desc_ptr); + else + ctxt->ops->set_idt(ctxt, &desc_ptr); + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_lgdt(struct x86_emulate_ctxt *ctxt) +{ + return em_lgdt_lidt(ctxt, true); +} + +static int em_lidt(struct x86_emulate_ctxt *ctxt) +{ + return em_lgdt_lidt(ctxt, false); +} + +static int em_smsw(struct x86_emulate_ctxt *ctxt) +{ + if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && + ctxt->ops->cpl(ctxt) > 0) + return emulate_gp(ctxt, 0); + + if (ctxt->dst.type == OP_MEM) + ctxt->dst.bytes = 2; + ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0); + return X86EMUL_CONTINUE; +} + +static int em_lmsw(struct x86_emulate_ctxt *ctxt) +{ + ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul) + | (ctxt->src.val & 0x0f)); + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_loop(struct x86_emulate_ctxt *ctxt) +{ + int rc = X86EMUL_CONTINUE; + + register_address_increment(ctxt, VCPU_REGS_RCX, -1); + if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) && + (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags))) + rc = jmp_rel(ctxt, ctxt->src.val); + + return rc; +} + +static int em_jcxz(struct x86_emulate_ctxt *ctxt) +{ + int rc = X86EMUL_CONTINUE; + + if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) + rc = jmp_rel(ctxt, ctxt->src.val); + + return rc; +} + +static int em_in(struct x86_emulate_ctxt *ctxt) +{ + if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val, + &ctxt->dst.val)) + return X86EMUL_IO_NEEDED; + + return X86EMUL_CONTINUE; +} + +static int em_out(struct x86_emulate_ctxt *ctxt) +{ + ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val, + &ctxt->src.val, 1); + /* Disable writeback. */ + ctxt->dst.type = OP_NONE; + return X86EMUL_CONTINUE; +} + +static int em_cli(struct x86_emulate_ctxt *ctxt) +{ + if (emulator_bad_iopl(ctxt)) + return emulate_gp(ctxt, 0); + + ctxt->eflags &= ~X86_EFLAGS_IF; + return X86EMUL_CONTINUE; +} + +static int em_sti(struct x86_emulate_ctxt *ctxt) +{ + if (emulator_bad_iopl(ctxt)) + return emulate_gp(ctxt, 0); + + ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; + ctxt->eflags |= X86_EFLAGS_IF; + return X86EMUL_CONTINUE; +} + +static int em_cpuid(struct x86_emulate_ctxt *ctxt) +{ + u32 eax, ebx, ecx, edx; + u64 msr = 0; + + ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr); + if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && + ctxt->ops->cpl(ctxt)) { + return emulate_gp(ctxt, 0); + } + + eax = reg_read(ctxt, VCPU_REGS_RAX); + ecx = reg_read(ctxt, VCPU_REGS_RCX); + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); + *reg_write(ctxt, VCPU_REGS_RAX) = eax; + *reg_write(ctxt, VCPU_REGS_RBX) = ebx; + *reg_write(ctxt, VCPU_REGS_RCX) = ecx; + *reg_write(ctxt, VCPU_REGS_RDX) = edx; + return X86EMUL_CONTINUE; +} + +static int em_sahf(struct x86_emulate_ctxt *ctxt) +{ + u32 flags; + + flags = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF | + X86_EFLAGS_SF; + flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8; + + ctxt->eflags &= ~0xffUL; + ctxt->eflags |= flags | X86_EFLAGS_FIXED; + return X86EMUL_CONTINUE; +} + +static int em_lahf(struct x86_emulate_ctxt *ctxt) +{ + *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL; + *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8; + return X86EMUL_CONTINUE; +} + +static int em_bswap(struct x86_emulate_ctxt *ctxt) +{ + switch (ctxt->op_bytes) { +#ifdef CONFIG_X86_64 + case 8: + asm("bswap %0" : "+r"(ctxt->dst.val)); + break; +#endif + default: + asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val)); + break; + } + return X86EMUL_CONTINUE; +} + +static int em_clflush(struct x86_emulate_ctxt *ctxt) +{ + /* emulating clflush regardless of cpuid */ + return X86EMUL_CONTINUE; +} + +static int em_clflushopt(struct x86_emulate_ctxt *ctxt) +{ + /* emulating clflushopt regardless of cpuid */ + return X86EMUL_CONTINUE; +} + +static int em_movsxd(struct x86_emulate_ctxt *ctxt) +{ + ctxt->dst.val = (s32) ctxt->src.val; + return X86EMUL_CONTINUE; +} + +static int check_fxsr(struct x86_emulate_ctxt *ctxt) +{ + u32 eax = 1, ebx, ecx = 0, edx; + + ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); + if (!(edx & FFL(FXSR))) + return emulate_ud(ctxt); + + if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) + return emulate_nm(ctxt); + + /* + * Don't emulate a case that should never be hit, instead of working + * around a lack of fxsave64/fxrstor64 on old compilers. + */ + if (ctxt->mode >= X86EMUL_MODE_PROT64) + return X86EMUL_UNHANDLEABLE; + + return X86EMUL_CONTINUE; +} + +/* + * Hardware doesn't save and restore XMM 0-7 without CR4.OSFXSR, but does save + * and restore MXCSR. + */ +static size_t __fxstate_size(int nregs) +{ + return offsetof(struct fxregs_state, xmm_space[0]) + nregs * 16; +} + +static inline size_t fxstate_size(struct x86_emulate_ctxt *ctxt) +{ + bool cr4_osfxsr; + if (ctxt->mode == X86EMUL_MODE_PROT64) + return __fxstate_size(16); + + cr4_osfxsr = ctxt->ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR; + return __fxstate_size(cr4_osfxsr ? 8 : 0); +} + +/* + * FXSAVE and FXRSTOR have 4 different formats depending on execution mode, + * 1) 16 bit mode + * 2) 32 bit mode + * - like (1), but FIP and FDP (foo) are only 16 bit. At least Intel CPUs + * preserve whole 32 bit values, though, so (1) and (2) are the same wrt. + * save and restore + * 3) 64-bit mode with REX.W prefix + * - like (2), but XMM 8-15 are being saved and restored + * 4) 64-bit mode without REX.W prefix + * - like (3), but FIP and FDP are 64 bit + * + * Emulation uses (3) for (1) and (2) and preserves XMM 8-15 to reach the + * desired result. (4) is not emulated. + * + * Note: Guest and host CPUID.(EAX=07H,ECX=0H):EBX[bit 13] (deprecate FPU CS + * and FPU DS) should match. + */ +static int em_fxsave(struct x86_emulate_ctxt *ctxt) +{ + struct fxregs_state fx_state; + int rc; + + rc = check_fxsr(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state)); + + if (rc != X86EMUL_CONTINUE) + return rc; + + return segmented_write_std(ctxt, ctxt->memop.addr.mem, &fx_state, + fxstate_size(ctxt)); +} + +/* + * FXRSTOR might restore XMM registers not provided by the guest. Fill + * in the host registers (via FXSAVE) instead, so they won't be modified. + * (preemption has to stay disabled until FXRSTOR). + * + * Use noinline to keep the stack for other functions called by callers small. + */ +static noinline int fxregs_fixup(struct fxregs_state *fx_state, + const size_t used_size) +{ + struct fxregs_state fx_tmp; + int rc; + + rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_tmp)); + memcpy((void *)fx_state + used_size, (void *)&fx_tmp + used_size, + __fxstate_size(16) - used_size); + + return rc; +} + +static int em_fxrstor(struct x86_emulate_ctxt *ctxt) +{ + struct fxregs_state fx_state; + int rc; + size_t size; + + rc = check_fxsr(ctxt); + if (rc != X86EMUL_CONTINUE) + return rc; + + size = fxstate_size(ctxt); + rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, size); + if (rc != X86EMUL_CONTINUE) + return rc; + + if (size < __fxstate_size(16)) { + rc = fxregs_fixup(&fx_state, size); + if (rc != X86EMUL_CONTINUE) + goto out; + } + + if (fx_state.mxcsr >> 16) { + rc = emulate_gp(ctxt, 0); + goto out; + } + + if (rc == X86EMUL_CONTINUE) + rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state)); + +out: + return rc; +} + +static bool valid_cr(int nr) +{ + switch (nr) { + case 0: + case 2 ... 4: + case 8: + return true; + default: + return false; + } +} + +static int check_cr_read(struct x86_emulate_ctxt *ctxt) +{ + if (!valid_cr(ctxt->modrm_reg)) + return emulate_ud(ctxt); + + return X86EMUL_CONTINUE; +} + +static int check_cr_write(struct x86_emulate_ctxt *ctxt) +{ + u64 new_val = ctxt->src.val64; + int cr = ctxt->modrm_reg; + u64 efer = 0; + + static u64 cr_reserved_bits[] = { + 0xffffffff00000000ULL, + 0, 0, 0, /* CR3 checked later */ + CR4_RESERVED_BITS, + 0, 0, 0, + CR8_RESERVED_BITS, + }; + + if (!valid_cr(cr)) + return emulate_ud(ctxt); + + if (new_val & cr_reserved_bits[cr]) + return emulate_gp(ctxt, 0); + + switch (cr) { + case 0: { + u64 cr4; + if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) || + ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD))) + return emulate_gp(ctxt, 0); + + cr4 = ctxt->ops->get_cr(ctxt, 4); + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + + if ((new_val & X86_CR0_PG) && (efer & EFER_LME) && + !(cr4 & X86_CR4_PAE)) + return emulate_gp(ctxt, 0); + + break; + } + case 3: { + u64 rsvd = 0; + + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + if (efer & EFER_LMA) { + u64 maxphyaddr; + u32 eax, ebx, ecx, edx; + + eax = 0x80000008; + ecx = 0; + if (ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, + &edx, false)) + maxphyaddr = eax & 0xff; + else + maxphyaddr = 36; + rsvd = rsvd_bits(maxphyaddr, 63); + if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PCIDE) + rsvd &= ~X86_CR3_PCID_NOFLUSH; + } + + if (new_val & rsvd) + return emulate_gp(ctxt, 0); + + break; + } + case 4: { + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + + if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE)) + return emulate_gp(ctxt, 0); + + break; + } + } + + return X86EMUL_CONTINUE; +} + +static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) +{ + unsigned long dr7; + + ctxt->ops->get_dr(ctxt, 7, &dr7); + + /* Check if DR7.Global_Enable is set */ + return dr7 & (1 << 13); +} + +static int check_dr_read(struct x86_emulate_ctxt *ctxt) +{ + int dr = ctxt->modrm_reg; + u64 cr4; + + if (dr > 7) + return emulate_ud(ctxt); + + cr4 = ctxt->ops->get_cr(ctxt, 4); + if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) + return emulate_ud(ctxt); + + if (check_dr7_gd(ctxt)) { + ulong dr6; + + ctxt->ops->get_dr(ctxt, 6, &dr6); + dr6 &= ~15; + dr6 |= DR6_BD | DR6_RTM; + ctxt->ops->set_dr(ctxt, 6, dr6); + return emulate_db(ctxt); + } + + return X86EMUL_CONTINUE; +} + +static int check_dr_write(struct x86_emulate_ctxt *ctxt) +{ + u64 new_val = ctxt->src.val64; + int dr = ctxt->modrm_reg; + + if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) + return emulate_gp(ctxt, 0); + + return check_dr_read(ctxt); +} + +static int check_svme(struct x86_emulate_ctxt *ctxt) +{ + u64 efer = 0; + + ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); + + if (!(efer & EFER_SVME)) + return emulate_ud(ctxt); + + return X86EMUL_CONTINUE; +} + +static int check_svme_pa(struct x86_emulate_ctxt *ctxt) +{ + u64 rax = reg_read(ctxt, VCPU_REGS_RAX); + + /* Valid physical address? */ + if (rax & 0xffff000000000000ULL) + return emulate_gp(ctxt, 0); + + return check_svme(ctxt); +} + +static int check_rdtsc(struct x86_emulate_ctxt *ctxt) +{ + u64 cr4 = ctxt->ops->get_cr(ctxt, 4); + + if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt)) + return emulate_ud(ctxt); + + return X86EMUL_CONTINUE; +} + +static int check_rdpmc(struct x86_emulate_ctxt *ctxt) +{ + u64 cr4 = ctxt->ops->get_cr(ctxt, 4); + u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); + + /* + * VMware allows access to these Pseduo-PMCs even when read via RDPMC + * in Ring3 when CR4.PCE=0. + */ + if (enable_vmware_backdoor && is_vmware_backdoor_pmc(rcx)) + return X86EMUL_CONTINUE; + + if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || + ctxt->ops->check_pmc(ctxt, rcx)) + return emulate_gp(ctxt, 0); + + return X86EMUL_CONTINUE; +} + +static int check_perm_in(struct x86_emulate_ctxt *ctxt) +{ + ctxt->dst.bytes = min(ctxt->dst.bytes, 4u); + if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes)) + return emulate_gp(ctxt, 0); + + return X86EMUL_CONTINUE; +} + +static int check_perm_out(struct x86_emulate_ctxt *ctxt) +{ + ctxt->src.bytes = min(ctxt->src.bytes, 4u); + if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes)) + return emulate_gp(ctxt, 0); + + return X86EMUL_CONTINUE; +} + +#define D(_y) { .flags = (_y) } +#define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i } +#define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \ + .intercept = x86_intercept_##_i, .check_perm = (_p) } +#define N D(NotImpl) +#define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } +#define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) } +#define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) } +#define ID(_f, _i) { .flags = ((_f) | InstrDual | ModRM), .u.idual = (_i) } +#define MD(_f, _m) { .flags = ((_f) | ModeDual), .u.mdual = (_m) } +#define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) } +#define I(_f, _e) { .flags = (_f), .u.execute = (_e) } +#define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) } +#define II(_f, _e, _i) \ + { .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i } +#define IIP(_f, _e, _i, _p) \ + { .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \ + .intercept = x86_intercept_##_i, .check_perm = (_p) } +#define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) } + +#define D2bv(_f) D((_f) | ByteOp), D(_f) +#define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p) +#define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) +#define F2bv(_f, _e) F((_f) | ByteOp, _e), F(_f, _e) +#define I2bvIP(_f, _e, _i, _p) \ + IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p) + +#define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e), \ + F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ + F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) + +static const struct opcode group7_rm0[] = { + N, + I(SrcNone | Priv | EmulateOnUD, em_hypercall), + N, N, N, N, N, N, +}; + +static const struct opcode group7_rm1[] = { + DI(SrcNone | Priv, monitor), + DI(SrcNone | Priv, mwait), + N, N, N, N, N, N, +}; + +static const struct opcode group7_rm3[] = { + DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa), + II(SrcNone | Prot | EmulateOnUD, em_hypercall, vmmcall), + DIP(SrcNone | Prot | Priv, vmload, check_svme_pa), + DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa), + DIP(SrcNone | Prot | Priv, stgi, check_svme), + DIP(SrcNone | Prot | Priv, clgi, check_svme), + DIP(SrcNone | Prot | Priv, skinit, check_svme), + DIP(SrcNone | Prot | Priv, invlpga, check_svme), +}; + +static const struct opcode group7_rm7[] = { + N, + DIP(SrcNone, rdtscp, check_rdtsc), + N, N, N, N, N, N, +}; + +static const struct opcode group1[] = { + F(Lock, em_add), + F(Lock | PageTable, em_or), + F(Lock, em_adc), + F(Lock, em_sbb), + F(Lock | PageTable, em_and), + F(Lock, em_sub), + F(Lock, em_xor), + F(NoWrite, em_cmp), +}; + +static const struct opcode group1A[] = { + I(DstMem | SrcNone | Mov | Stack | IncSP | TwoMemOp, em_pop), N, N, N, N, N, N, N, +}; + +static const struct opcode group2[] = { + F(DstMem | ModRM, em_rol), + F(DstMem | ModRM, em_ror), + F(DstMem | ModRM, em_rcl), + F(DstMem | ModRM, em_rcr), + F(DstMem | ModRM, em_shl), + F(DstMem | ModRM, em_shr), + F(DstMem | ModRM, em_shl), + F(DstMem | ModRM, em_sar), +}; + +static const struct opcode group3[] = { + F(DstMem | SrcImm | NoWrite, em_test), + F(DstMem | SrcImm | NoWrite, em_test), + F(DstMem | SrcNone | Lock, em_not), + F(DstMem | SrcNone | Lock, em_neg), + F(DstXacc | Src2Mem, em_mul_ex), + F(DstXacc | Src2Mem, em_imul_ex), + F(DstXacc | Src2Mem, em_div_ex), + F(DstXacc | Src2Mem, em_idiv_ex), +}; + +static const struct opcode group4[] = { + F(ByteOp | DstMem | SrcNone | Lock, em_inc), + F(ByteOp | DstMem | SrcNone | Lock, em_dec), + N, N, N, N, N, N, +}; + +static const struct opcode group5[] = { + F(DstMem | SrcNone | Lock, em_inc), + F(DstMem | SrcNone | Lock, em_dec), + I(SrcMem | NearBranch, em_call_near_abs), + I(SrcMemFAddr | ImplicitOps, em_call_far), + I(SrcMem | NearBranch, em_jmp_abs), + I(SrcMemFAddr | ImplicitOps, em_jmp_far), + I(SrcMem | Stack | TwoMemOp, em_push), D(Undefined), +}; + +static const struct opcode group6[] = { + II(Prot | DstMem, em_sldt, sldt), + II(Prot | DstMem, em_str, str), + II(Prot | Priv | SrcMem16, em_lldt, lldt), + II(Prot | Priv | SrcMem16, em_ltr, ltr), + N, N, N, N, +}; + +static const struct group_dual group7 = { { + II(Mov | DstMem, em_sgdt, sgdt), + II(Mov | DstMem, em_sidt, sidt), + II(SrcMem | Priv, em_lgdt, lgdt), + II(SrcMem | Priv, em_lidt, lidt), + II(SrcNone | DstMem | Mov, em_smsw, smsw), N, + II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), + II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg), +}, { + EXT(0, group7_rm0), + EXT(0, group7_rm1), + N, EXT(0, group7_rm3), + II(SrcNone | DstMem | Mov, em_smsw, smsw), N, + II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), + EXT(0, group7_rm7), +} }; + +static const struct opcode group8[] = { + N, N, N, N, + F(DstMem | SrcImmByte | NoWrite, em_bt), + F(DstMem | SrcImmByte | Lock | PageTable, em_bts), + F(DstMem | SrcImmByte | Lock, em_btr), + F(DstMem | SrcImmByte | Lock | PageTable, em_btc), +}; + +/* + * The "memory" destination is actually always a register, since we come + * from the register case of group9. + */ +static const struct gprefix pfx_0f_c7_7 = { + N, N, N, II(DstMem | ModRM | Op3264 | EmulateOnUD, em_rdpid, rdtscp), +}; + + +static const struct group_dual group9 = { { + N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N, +}, { + N, N, N, N, N, N, N, + GP(0, &pfx_0f_c7_7), +} }; + +static const struct opcode group11[] = { + I(DstMem | SrcImm | Mov | PageTable, em_mov), + X7(D(Undefined)), +}; + +static const struct gprefix pfx_0f_ae_7 = { + I(SrcMem | ByteOp, em_clflush), I(SrcMem | ByteOp, em_clflushopt), N, N, +}; + +static const struct group_dual group15 = { { + I(ModRM | Aligned16, em_fxsave), + I(ModRM | Aligned16, em_fxrstor), + N, N, N, N, N, GP(0, &pfx_0f_ae_7), +}, { + N, N, N, N, N, N, N, N, +} }; + +static const struct gprefix pfx_0f_6f_0f_7f = { + I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov), +}; + +static const struct instr_dual instr_dual_0f_2b = { + I(0, em_mov), N +}; + +static const struct gprefix pfx_0f_2b = { + ID(0, &instr_dual_0f_2b), ID(0, &instr_dual_0f_2b), N, N, +}; + +static const struct gprefix pfx_0f_10_0f_11 = { + I(Unaligned, em_mov), I(Unaligned, em_mov), N, N, +}; + +static const struct gprefix pfx_0f_28_0f_29 = { + I(Aligned, em_mov), I(Aligned, em_mov), N, N, +}; + +static const struct gprefix pfx_0f_e7 = { + N, I(Sse, em_mov), N, N, +}; + +static const struct escape escape_d9 = { { + N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstcw), +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, N, N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + +static const struct escape escape_db = { { + N, N, N, N, N, N, N, N, +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, I(ImplicitOps, em_fninit), N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + +static const struct escape escape_dd = { { + N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstsw), +}, { + /* 0xC0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xC8 - 0xCF */ + N, N, N, N, N, N, N, N, + /* 0xD0 - 0xC7 */ + N, N, N, N, N, N, N, N, + /* 0xD8 - 0xDF */ + N, N, N, N, N, N, N, N, + /* 0xE0 - 0xE7 */ + N, N, N, N, N, N, N, N, + /* 0xE8 - 0xEF */ + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xF7 */ + N, N, N, N, N, N, N, N, + /* 0xF8 - 0xFF */ + N, N, N, N, N, N, N, N, +} }; + +static const struct instr_dual instr_dual_0f_c3 = { + I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov), N +}; + +static const struct mode_dual mode_dual_63 = { + N, I(DstReg | SrcMem32 | ModRM | Mov, em_movsxd) +}; + +static const struct opcode opcode_table[256] = { + /* 0x00 - 0x07 */ + F6ALU(Lock, em_add), + I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg), + I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg), + /* 0x08 - 0x0F */ + F6ALU(Lock | PageTable, em_or), + I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg), + N, + /* 0x10 - 0x17 */ + F6ALU(Lock, em_adc), + I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg), + I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg), + /* 0x18 - 0x1F */ + F6ALU(Lock, em_sbb), + I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg), + I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg), + /* 0x20 - 0x27 */ + F6ALU(Lock | PageTable, em_and), N, N, + /* 0x28 - 0x2F */ + F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), + /* 0x30 - 0x37 */ + F6ALU(Lock, em_xor), N, N, + /* 0x38 - 0x3F */ + F6ALU(NoWrite, em_cmp), N, N, + /* 0x40 - 0x4F */ + X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)), + /* 0x50 - 0x57 */ + X8(I(SrcReg | Stack, em_push)), + /* 0x58 - 0x5F */ + X8(I(DstReg | Stack, em_pop)), + /* 0x60 - 0x67 */ + I(ImplicitOps | Stack | No64, em_pusha), + I(ImplicitOps | Stack | No64, em_popa), + N, MD(ModRM, &mode_dual_63), + N, N, N, N, + /* 0x68 - 0x6F */ + I(SrcImm | Mov | Stack, em_push), + I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), + I(SrcImmByte | Mov | Stack, em_push), + I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), + I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ + I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ + /* 0x70 - 0x7F */ + X16(D(SrcImmByte | NearBranch)), + /* 0x80 - 0x87 */ + G(ByteOp | DstMem | SrcImm, group1), + G(DstMem | SrcImm, group1), + G(ByteOp | DstMem | SrcImm | No64, group1), + G(DstMem | SrcImmByte, group1), + F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test), + I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg), + /* 0x88 - 0x8F */ + I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov), + I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), + I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg), + D(ModRM | SrcMem | NoAccess | DstReg), + I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm), + G(0, group1A), + /* 0x90 - 0x97 */ + DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)), + /* 0x98 - 0x9F */ + D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd), + I(SrcImmFAddr | No64, em_call_far), N, + II(ImplicitOps | Stack, em_pushf, pushf), + II(ImplicitOps | Stack, em_popf, popf), + I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf), + /* 0xA0 - 0xA7 */ + I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), + I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov), + I2bv(SrcSI | DstDI | Mov | String | TwoMemOp, em_mov), + F2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r), + /* 0xA8 - 0xAF */ + F2bv(DstAcc | SrcImm | NoWrite, em_test), + I2bv(SrcAcc | DstDI | Mov | String, em_mov), + I2bv(SrcSI | DstAcc | Mov | String, em_mov), + F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r), + /* 0xB0 - 0xB7 */ + X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)), + /* 0xB8 - 0xBF */ + X8(I(DstReg | SrcImm64 | Mov, em_mov)), + /* 0xC0 - 0xC7 */ + G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2), + I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm), + I(ImplicitOps | NearBranch, em_ret), + I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg), + I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), + G(ByteOp, group11), G(0, group11), + /* 0xC8 - 0xCF */ + I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave), + I(ImplicitOps | SrcImmU16, em_ret_far_imm), + I(ImplicitOps, em_ret_far), + D(ImplicitOps), DI(SrcImmByte, intn), + D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret), + /* 0xD0 - 0xD7 */ + G(Src2One | ByteOp, group2), G(Src2One, group2), + G(Src2CL | ByteOp, group2), G(Src2CL, group2), + I(DstAcc | SrcImmUByte | No64, em_aam), + I(DstAcc | SrcImmUByte | No64, em_aad), + F(DstAcc | ByteOp | No64, em_salc), + I(DstAcc | SrcXLat | ByteOp, em_mov), + /* 0xD8 - 0xDF */ + N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, + /* 0xE0 - 0xE7 */ + X3(I(SrcImmByte | NearBranch, em_loop)), + I(SrcImmByte | NearBranch, em_jcxz), + I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in), + I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out), + /* 0xE8 - 0xEF */ + I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch), + I(SrcImmFAddr | No64, em_jmp_far), + D(SrcImmByte | ImplicitOps | NearBranch), + I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in), + I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out), + /* 0xF0 - 0xF7 */ + N, DI(ImplicitOps, icebp), N, N, + DI(ImplicitOps | Priv, hlt), D(ImplicitOps), + G(ByteOp, group3), G(0, group3), + /* 0xF8 - 0xFF */ + D(ImplicitOps), D(ImplicitOps), + I(ImplicitOps, em_cli), I(ImplicitOps, em_sti), + D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5), +}; + +static const struct opcode twobyte_table[256] = { + /* 0x00 - 0x0F */ + G(0, group6), GD(0, &group7), N, N, + N, I(ImplicitOps | EmulateOnUD, em_syscall), + II(ImplicitOps | Priv, em_clts, clts), N, + DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, + N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, + /* 0x10 - 0x1F */ + GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_10_0f_11), + GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_10_0f_11), + N, N, N, N, N, N, + D(ImplicitOps | ModRM | SrcMem | NoAccess), + N, N, N, N, N, N, D(ImplicitOps | ModRM | SrcMem | NoAccess), + /* 0x20 - 0x2F */ + DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read), + DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read), + IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write, + check_cr_write), + IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write, + check_dr_write), + N, N, N, N, + GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29), + GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29), + N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b), + N, N, N, N, + /* 0x30 - 0x3F */ + II(ImplicitOps | Priv, em_wrmsr, wrmsr), + IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc), + II(ImplicitOps | Priv, em_rdmsr, rdmsr), + IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc), + I(ImplicitOps | EmulateOnUD, em_sysenter), + I(ImplicitOps | Priv | EmulateOnUD, em_sysexit), + N, N, + N, N, N, N, N, N, N, N, + /* 0x40 - 0x4F */ + X16(D(DstReg | SrcMem | ModRM)), + /* 0x50 - 0x5F */ + N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, + /* 0x60 - 0x6F */ + N, N, N, N, + N, N, N, N, + N, N, N, N, + N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f), + /* 0x70 - 0x7F */ + N, N, N, N, + N, N, N, N, + N, N, N, N, + N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f), + /* 0x80 - 0x8F */ + X16(D(SrcImm | NearBranch)), + /* 0x90 - 0x9F */ + X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)), + /* 0xA0 - 0xA7 */ + I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg), + II(ImplicitOps, em_cpuid, cpuid), + F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt), + F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld), + F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N, + /* 0xA8 - 0xAF */ + I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg), + II(EmulateOnUD | ImplicitOps, em_rsm, rsm), + F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts), + F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd), + F(DstMem | SrcReg | Src2CL | ModRM, em_shrd), + GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul), + /* 0xB0 - 0xB7 */ + I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg), + I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), + F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr), + I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg), + I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg), + D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), + /* 0xB8 - 0xBF */ + N, N, + G(BitOp, group8), + F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc), + I(DstReg | SrcMem | ModRM, em_bsf_c), + I(DstReg | SrcMem | ModRM, em_bsr_c), + D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), + /* 0xC0 - 0xC7 */ + F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd), + N, ID(0, &instr_dual_0f_c3), + N, N, N, GD(0, &group9), + /* 0xC8 - 0xCF */ + X8(I(DstReg, em_bswap)), + /* 0xD0 - 0xDF */ + N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, + /* 0xE0 - 0xEF */ + N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7), + N, N, N, N, N, N, N, N, + /* 0xF0 - 0xFF */ + N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N +}; + +static const struct instr_dual instr_dual_0f_38_f0 = { + I(DstReg | SrcMem | Mov, em_movbe), N +}; + +static const struct instr_dual instr_dual_0f_38_f1 = { + I(DstMem | SrcReg | Mov, em_movbe), N +}; + +static const struct gprefix three_byte_0f_38_f0 = { + ID(0, &instr_dual_0f_38_f0), N, N, N +}; + +static const struct gprefix three_byte_0f_38_f1 = { + ID(0, &instr_dual_0f_38_f1), N, N, N +}; + +/* + * Insns below are selected by the prefix which indexed by the third opcode + * byte. + */ +static const struct opcode opcode_map_0f_38[256] = { + /* 0x00 - 0x7f */ + X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), + /* 0x80 - 0xef */ + X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), + /* 0xf0 - 0xf1 */ + GP(EmulateOnUD | ModRM, &three_byte_0f_38_f0), + GP(EmulateOnUD | ModRM, &three_byte_0f_38_f1), + /* 0xf2 - 0xff */ + N, N, X4(N), X8(N) +}; + +#undef D +#undef N +#undef G +#undef GD +#undef I +#undef GP +#undef EXT +#undef MD +#undef ID + +#undef D2bv +#undef D2bvIP +#undef I2bv +#undef I2bvIP +#undef I6ALU + +static unsigned imm_size(struct x86_emulate_ctxt *ctxt) +{ + unsigned size; + + size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + if (size == 8) + size = 4; + return size; +} + +static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op, + unsigned size, bool sign_extension) +{ + int rc = X86EMUL_CONTINUE; + + op->type = OP_IMM; + op->bytes = size; + op->addr.mem.ea = ctxt->_eip; + /* NB. Immediates are sign-extended as necessary. */ + switch (op->bytes) { + case 1: + op->val = insn_fetch(s8, ctxt); + break; + case 2: + op->val = insn_fetch(s16, ctxt); + break; + case 4: + op->val = insn_fetch(s32, ctxt); + break; + case 8: + op->val = insn_fetch(s64, ctxt); + break; + } + if (!sign_extension) { + switch (op->bytes) { + case 1: + op->val &= 0xff; + break; + case 2: + op->val &= 0xffff; + break; + case 4: + op->val &= 0xffffffff; + break; + } + } +done: + return rc; +} + +static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, + unsigned d) +{ + int rc = X86EMUL_CONTINUE; + + switch (d) { + case OpReg: + decode_register_operand(ctxt, op); + break; + case OpImmUByte: + rc = decode_imm(ctxt, op, 1, false); + break; + case OpMem: + ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + mem_common: + *op = ctxt->memop; + ctxt->memopp = op; + if (ctxt->d & BitOp) + fetch_bit_operand(ctxt); + op->orig_val = op->val; + break; + case OpMem64: + ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8; + goto mem_common; + case OpAcc: + op->type = OP_REG; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); + fetch_register_operand(op); + op->orig_val = op->val; + break; + case OpAccLo: + op->type = OP_REG; + op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); + fetch_register_operand(op); + op->orig_val = op->val; + break; + case OpAccHi: + if (ctxt->d & ByteOp) { + op->type = OP_NONE; + break; + } + op->type = OP_REG; + op->bytes = ctxt->op_bytes; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); + fetch_register_operand(op); + op->orig_val = op->val; + break; + case OpDI: + op->type = OP_MEM; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.mem.ea = + register_address(ctxt, VCPU_REGS_RDI); + op->addr.mem.seg = VCPU_SREG_ES; + op->val = 0; + op->count = 1; + break; + case OpDX: + op->type = OP_REG; + op->bytes = 2; + op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); + fetch_register_operand(op); + break; + case OpCL: + op->type = OP_IMM; + op->bytes = 1; + op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; + break; + case OpImmByte: + rc = decode_imm(ctxt, op, 1, true); + break; + case OpOne: + op->type = OP_IMM; + op->bytes = 1; + op->val = 1; + break; + case OpImm: + rc = decode_imm(ctxt, op, imm_size(ctxt), true); + break; + case OpImm64: + rc = decode_imm(ctxt, op, ctxt->op_bytes, true); + break; + case OpMem8: + ctxt->memop.bytes = 1; + if (ctxt->memop.type == OP_REG) { + ctxt->memop.addr.reg = decode_register(ctxt, + ctxt->modrm_rm, true); + fetch_register_operand(&ctxt->memop); + } + goto mem_common; + case OpMem16: + ctxt->memop.bytes = 2; + goto mem_common; + case OpMem32: + ctxt->memop.bytes = 4; + goto mem_common; + case OpImmU16: + rc = decode_imm(ctxt, op, 2, false); + break; + case OpImmU: + rc = decode_imm(ctxt, op, imm_size(ctxt), false); + break; + case OpSI: + op->type = OP_MEM; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.mem.ea = + register_address(ctxt, VCPU_REGS_RSI); + op->addr.mem.seg = ctxt->seg_override; + op->val = 0; + op->count = 1; + break; + case OpXLat: + op->type = OP_MEM; + op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; + op->addr.mem.ea = + address_mask(ctxt, + reg_read(ctxt, VCPU_REGS_RBX) + + (reg_read(ctxt, VCPU_REGS_RAX) & 0xff)); + op->addr.mem.seg = ctxt->seg_override; + op->val = 0; + break; + case OpImmFAddr: + op->type = OP_IMM; + op->addr.mem.ea = ctxt->_eip; + op->bytes = ctxt->op_bytes + 2; + insn_fetch_arr(op->valptr, op->bytes, ctxt); + break; + case OpMemFAddr: + ctxt->memop.bytes = ctxt->op_bytes + 2; + goto mem_common; + case OpES: + op->type = OP_IMM; + op->val = VCPU_SREG_ES; + break; + case OpCS: + op->type = OP_IMM; + op->val = VCPU_SREG_CS; + break; + case OpSS: + op->type = OP_IMM; + op->val = VCPU_SREG_SS; + break; + case OpDS: + op->type = OP_IMM; + op->val = VCPU_SREG_DS; + break; + case OpFS: + op->type = OP_IMM; + op->val = VCPU_SREG_FS; + break; + case OpGS: + op->type = OP_IMM; + op->val = VCPU_SREG_GS; + break; + case OpImplicit: + /* Special instructions do their own operand decoding. */ + default: + op->type = OP_NONE; /* Disable writeback. */ + break; + } + +done: + return rc; +} + +int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) +{ + int rc = X86EMUL_CONTINUE; + int mode = ctxt->mode; + int def_op_bytes, def_ad_bytes, goffset, simd_prefix; + bool op_prefix = false; + bool has_seg_override = false; + struct opcode opcode; + u16 dummy; + struct desc_struct desc; + + ctxt->memop.type = OP_NONE; + ctxt->memopp = NULL; + ctxt->_eip = ctxt->eip; + ctxt->fetch.ptr = ctxt->fetch.data; + ctxt->fetch.end = ctxt->fetch.data + insn_len; + ctxt->opcode_len = 1; + ctxt->intercept = x86_intercept_none; + if (insn_len > 0) + memcpy(ctxt->fetch.data, insn, insn_len); + else { + rc = __do_insn_fetch_bytes(ctxt, 1); + if (rc != X86EMUL_CONTINUE) + return rc; + } + + switch (mode) { + case X86EMUL_MODE_REAL: + case X86EMUL_MODE_VM86: + def_op_bytes = def_ad_bytes = 2; + ctxt->ops->get_segment(ctxt, &dummy, &desc, NULL, VCPU_SREG_CS); + if (desc.d) + def_op_bytes = def_ad_bytes = 4; + break; + case X86EMUL_MODE_PROT16: + def_op_bytes = def_ad_bytes = 2; + break; + case X86EMUL_MODE_PROT32: + def_op_bytes = def_ad_bytes = 4; + break; +#ifdef CONFIG_X86_64 + case X86EMUL_MODE_PROT64: + def_op_bytes = 4; + def_ad_bytes = 8; + break; +#endif + default: + return EMULATION_FAILED; + } + + ctxt->op_bytes = def_op_bytes; + ctxt->ad_bytes = def_ad_bytes; + + /* Legacy prefixes. */ + for (;;) { + switch (ctxt->b = insn_fetch(u8, ctxt)) { + case 0x66: /* operand-size override */ + op_prefix = true; + /* switch between 2/4 bytes */ + ctxt->op_bytes = def_op_bytes ^ 6; + break; + case 0x67: /* address-size override */ + if (mode == X86EMUL_MODE_PROT64) + /* switch between 4/8 bytes */ + ctxt->ad_bytes = def_ad_bytes ^ 12; + else + /* switch between 2/4 bytes */ + ctxt->ad_bytes = def_ad_bytes ^ 6; + break; + case 0x26: /* ES override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_ES; + break; + case 0x2e: /* CS override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_CS; + break; + case 0x36: /* SS override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_SS; + break; + case 0x3e: /* DS override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_DS; + break; + case 0x64: /* FS override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_FS; + break; + case 0x65: /* GS override */ + has_seg_override = true; + ctxt->seg_override = VCPU_SREG_GS; + break; + case 0x40 ... 0x4f: /* REX */ + if (mode != X86EMUL_MODE_PROT64) + goto done_prefixes; + ctxt->rex_prefix = ctxt->b; + continue; + case 0xf0: /* LOCK */ + ctxt->lock_prefix = 1; + break; + case 0xf2: /* REPNE/REPNZ */ + case 0xf3: /* REP/REPE/REPZ */ + ctxt->rep_prefix = ctxt->b; + break; + default: + goto done_prefixes; + } + + /* Any legacy prefix after a REX prefix nullifies its effect. */ + + ctxt->rex_prefix = 0; + } + +done_prefixes: + + /* REX prefix. */ + if (ctxt->rex_prefix & 8) + ctxt->op_bytes = 8; /* REX.W */ + + /* Opcode byte(s). */ + opcode = opcode_table[ctxt->b]; + /* Two-byte opcode? */ + if (ctxt->b == 0x0f) { + ctxt->opcode_len = 2; + ctxt->b = insn_fetch(u8, ctxt); + opcode = twobyte_table[ctxt->b]; + + /* 0F_38 opcode map */ + if (ctxt->b == 0x38) { + ctxt->opcode_len = 3; + ctxt->b = insn_fetch(u8, ctxt); + opcode = opcode_map_0f_38[ctxt->b]; + } + } + ctxt->d = opcode.flags; + + if (ctxt->d & ModRM) + ctxt->modrm = insn_fetch(u8, ctxt); + + /* vex-prefix instructions are not implemented */ + if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) && + (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) { + ctxt->d = NotImpl; + } + + while (ctxt->d & GroupMask) { + switch (ctxt->d & GroupMask) { + case Group: + goffset = (ctxt->modrm >> 3) & 7; + opcode = opcode.u.group[goffset]; + break; + case GroupDual: + goffset = (ctxt->modrm >> 3) & 7; + if ((ctxt->modrm >> 6) == 3) + opcode = opcode.u.gdual->mod3[goffset]; + else + opcode = opcode.u.gdual->mod012[goffset]; + break; + case RMExt: + goffset = ctxt->modrm & 7; + opcode = opcode.u.group[goffset]; + break; + case Prefix: + if (ctxt->rep_prefix && op_prefix) + return EMULATION_FAILED; + simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix; + switch (simd_prefix) { + case 0x00: opcode = opcode.u.gprefix->pfx_no; break; + case 0x66: opcode = opcode.u.gprefix->pfx_66; break; + case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break; + case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; + } + break; + case Escape: + if (ctxt->modrm > 0xbf) { + size_t size = ARRAY_SIZE(opcode.u.esc->high); + u32 index = array_index_nospec( + ctxt->modrm - 0xc0, size); + + opcode = opcode.u.esc->high[index]; + } else { + opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7]; + } + break; + case InstrDual: + if ((ctxt->modrm >> 6) == 3) + opcode = opcode.u.idual->mod3; + else + opcode = opcode.u.idual->mod012; + break; + case ModeDual: + if (ctxt->mode == X86EMUL_MODE_PROT64) + opcode = opcode.u.mdual->mode64; + else + opcode = opcode.u.mdual->mode32; + break; + default: + return EMULATION_FAILED; + } + + ctxt->d &= ~(u64)GroupMask; + ctxt->d |= opcode.flags; + } + + /* Unrecognised? */ + if (ctxt->d == 0) + return EMULATION_FAILED; + + ctxt->execute = opcode.u.execute; + + if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD))) + return EMULATION_FAILED; + + if (unlikely(ctxt->d & + (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch| + No16))) { + /* + * These are copied unconditionally here, and checked unconditionally + * in x86_emulate_insn. + */ + ctxt->check_perm = opcode.check_perm; + ctxt->intercept = opcode.intercept; + + if (ctxt->d & NotImpl) + return EMULATION_FAILED; + + if (mode == X86EMUL_MODE_PROT64) { + if (ctxt->op_bytes == 4 && (ctxt->d & Stack)) + ctxt->op_bytes = 8; + else if (ctxt->d & NearBranch) + ctxt->op_bytes = 8; + } + + if (ctxt->d & Op3264) { + if (mode == X86EMUL_MODE_PROT64) + ctxt->op_bytes = 8; + else + ctxt->op_bytes = 4; + } + + if ((ctxt->d & No16) && ctxt->op_bytes == 2) + ctxt->op_bytes = 4; + + if (ctxt->d & Sse) + ctxt->op_bytes = 16; + else if (ctxt->d & Mmx) + ctxt->op_bytes = 8; + } + + /* ModRM and SIB bytes. */ + if (ctxt->d & ModRM) { + rc = decode_modrm(ctxt, &ctxt->memop); + if (!has_seg_override) { + has_seg_override = true; + ctxt->seg_override = ctxt->modrm_seg; + } + } else if (ctxt->d & MemAbs) + rc = decode_abs(ctxt, &ctxt->memop); + if (rc != X86EMUL_CONTINUE) + goto done; + + if (!has_seg_override) + ctxt->seg_override = VCPU_SREG_DS; + + ctxt->memop.addr.mem.seg = ctxt->seg_override; + + /* + * Decode and fetch the source operand: register, memory + * or immediate. + */ + rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask); + if (rc != X86EMUL_CONTINUE) + goto done; + + /* + * Decode and fetch the second source operand: register, memory + * or immediate. + */ + rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask); + if (rc != X86EMUL_CONTINUE) + goto done; + + /* Decode and fetch the destination operand: register or memory. */ + rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); + + if (ctxt->rip_relative && likely(ctxt->memopp)) + ctxt->memopp->addr.mem.ea = address_mask(ctxt, + ctxt->memopp->addr.mem.ea + ctxt->_eip); + +done: + if (rc == X86EMUL_PROPAGATE_FAULT) + ctxt->have_exception = true; + return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK; +} + +bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt) +{ + return ctxt->d & PageTable; +} + +static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) +{ + /* The second termination condition only applies for REPE + * and REPNE. Test if the repeat string operation prefix is + * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the + * corresponding termination condition according to: + * - if REPE/REPZ and ZF = 0 then done + * - if REPNE/REPNZ and ZF = 1 then done + */ + if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) || + (ctxt->b == 0xae) || (ctxt->b == 0xaf)) + && (((ctxt->rep_prefix == REPE_PREFIX) && + ((ctxt->eflags & X86_EFLAGS_ZF) == 0)) + || ((ctxt->rep_prefix == REPNE_PREFIX) && + ((ctxt->eflags & X86_EFLAGS_ZF) == X86_EFLAGS_ZF)))) + return true; + + return false; +} + +static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) +{ + int rc; + + rc = asm_safe("fwait"); + + if (unlikely(rc != X86EMUL_CONTINUE)) + return emulate_exception(ctxt, MF_VECTOR, 0, false); + + return X86EMUL_CONTINUE; +} + +static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt, + struct operand *op) +{ + if (op->type == OP_MM) + read_mmx_reg(ctxt, &op->mm_val, op->addr.mm); +} + +static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *)) +{ + ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; + + if (!(ctxt->d & ByteOp)) + fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; + + asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n" + : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), + [thunk_target]"+S"(fop), ASM_CALL_CONSTRAINT + : "c"(ctxt->src2.val)); + + ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); + if (!fop) /* exception is returned in fop variable */ + return emulate_de(ctxt); + return X86EMUL_CONTINUE; +} + +void init_decode_cache(struct x86_emulate_ctxt *ctxt) +{ + memset(&ctxt->rip_relative, 0, + (void *)&ctxt->modrm - (void *)&ctxt->rip_relative); + + ctxt->io_read.pos = 0; + ctxt->io_read.end = 0; + ctxt->mem_read.end = 0; +} + +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) +{ + const struct x86_emulate_ops *ops = ctxt->ops; + int rc = X86EMUL_CONTINUE; + int saved_dst_type = ctxt->dst.type; + unsigned emul_flags; + + ctxt->mem_read.pos = 0; + + /* LOCK prefix is allowed only with some instructions */ + if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) { + rc = emulate_ud(ctxt); + goto done; + } + + if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) { + rc = emulate_ud(ctxt); + goto done; + } + + emul_flags = ctxt->ops->get_hflags(ctxt); + if (unlikely(ctxt->d & + (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) { + if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) || + (ctxt->d & Undefined)) { + rc = emulate_ud(ctxt); + goto done; + } + + if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM))) + || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) { + rc = emulate_ud(ctxt); + goto done; + } + + if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) { + rc = emulate_nm(ctxt); + goto done; + } + + if (ctxt->d & Mmx) { + rc = flush_pending_x87_faults(ctxt); + if (rc != X86EMUL_CONTINUE) + goto done; + /* + * Now that we know the fpu is exception safe, we can fetch + * operands from it. + */ + fetch_possible_mmx_operand(ctxt, &ctxt->src); + fetch_possible_mmx_operand(ctxt, &ctxt->src2); + if (!(ctxt->d & Mov)) + fetch_possible_mmx_operand(ctxt, &ctxt->dst); + } + + if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) { + rc = emulator_check_intercept(ctxt, ctxt->intercept, + X86_ICPT_PRE_EXCEPT); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + /* Instruction can only be executed in protected mode */ + if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) { + rc = emulate_ud(ctxt); + goto done; + } + + /* Privileged instruction can be executed only in CPL=0 */ + if ((ctxt->d & Priv) && ops->cpl(ctxt)) { + if (ctxt->d & PrivUD) + rc = emulate_ud(ctxt); + else + rc = emulate_gp(ctxt, 0); + goto done; + } + + /* Do instruction specific permission checks */ + if (ctxt->d & CheckPerm) { + rc = ctxt->check_perm(ctxt); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { + rc = emulator_check_intercept(ctxt, ctxt->intercept, + X86_ICPT_POST_EXCEPT); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + if (ctxt->rep_prefix && (ctxt->d & String)) { + /* All REP prefixes have the same first termination condition */ + if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) { + string_registers_quirk(ctxt); + ctxt->eip = ctxt->_eip; + ctxt->eflags &= ~X86_EFLAGS_RF; + goto done; + } + } + } + + if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) { + rc = segmented_read(ctxt, ctxt->src.addr.mem, + ctxt->src.valptr, ctxt->src.bytes); + if (rc != X86EMUL_CONTINUE) + goto done; + ctxt->src.orig_val64 = ctxt->src.val64; + } + + if (ctxt->src2.type == OP_MEM) { + rc = segmented_read(ctxt, ctxt->src2.addr.mem, + &ctxt->src2.val, ctxt->src2.bytes); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + if ((ctxt->d & DstMask) == ImplicitOps) + goto special_insn; + + + if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) { + /* optimisation - avoid slow emulated read if Mov */ + rc = segmented_read(ctxt, ctxt->dst.addr.mem, + &ctxt->dst.val, ctxt->dst.bytes); + if (rc != X86EMUL_CONTINUE) { + if (!(ctxt->d & NoWrite) && + rc == X86EMUL_PROPAGATE_FAULT && + ctxt->exception.vector == PF_VECTOR) + ctxt->exception.error_code |= PFERR_WRITE_MASK; + goto done; + } + } + /* Copy full 64-bit value for CMPXCHG8B. */ + ctxt->dst.orig_val64 = ctxt->dst.val64; + +special_insn: + + if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { + rc = emulator_check_intercept(ctxt, ctxt->intercept, + X86_ICPT_POST_MEMACCESS); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + if (ctxt->rep_prefix && (ctxt->d & String)) + ctxt->eflags |= X86_EFLAGS_RF; + else + ctxt->eflags &= ~X86_EFLAGS_RF; + + if (ctxt->execute) { + if (ctxt->d & Fastop) { + void (*fop)(struct fastop *) = (void *)ctxt->execute; + rc = fastop(ctxt, fop); + if (rc != X86EMUL_CONTINUE) + goto done; + goto writeback; + } + rc = ctxt->execute(ctxt); + if (rc != X86EMUL_CONTINUE) + goto done; + goto writeback; + } + + if (ctxt->opcode_len == 2) + goto twobyte_insn; + else if (ctxt->opcode_len == 3) + goto threebyte_insn; + + switch (ctxt->b) { + case 0x70 ... 0x7f: /* jcc (short) */ + if (test_cc(ctxt->b, ctxt->eflags)) + rc = jmp_rel(ctxt, ctxt->src.val); + break; + case 0x8d: /* lea r16/r32, m */ + ctxt->dst.val = ctxt->src.addr.mem.ea; + break; + case 0x90 ... 0x97: /* nop / xchg reg, rax */ + if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) + ctxt->dst.type = OP_NONE; + else + rc = em_xchg(ctxt); + break; + case 0x98: /* cbw/cwde/cdqe */ + switch (ctxt->op_bytes) { + case 2: ctxt->dst.val = (s8)ctxt->dst.val; break; + case 4: ctxt->dst.val = (s16)ctxt->dst.val; break; + case 8: ctxt->dst.val = (s32)ctxt->dst.val; break; + } + break; + case 0xcc: /* int3 */ + rc = emulate_int(ctxt, 3); + break; + case 0xcd: /* int n */ + rc = emulate_int(ctxt, ctxt->src.val); + break; + case 0xce: /* into */ + if (ctxt->eflags & X86_EFLAGS_OF) + rc = emulate_int(ctxt, 4); + break; + case 0xe9: /* jmp rel */ + case 0xeb: /* jmp rel short */ + rc = jmp_rel(ctxt, ctxt->src.val); + ctxt->dst.type = OP_NONE; /* Disable writeback. */ + break; + case 0xf4: /* hlt */ + ctxt->ops->halt(ctxt); + break; + case 0xf5: /* cmc */ + /* complement carry flag from eflags reg */ + ctxt->eflags ^= X86_EFLAGS_CF; + break; + case 0xf8: /* clc */ + ctxt->eflags &= ~X86_EFLAGS_CF; + break; + case 0xf9: /* stc */ + ctxt->eflags |= X86_EFLAGS_CF; + break; + case 0xfc: /* cld */ + ctxt->eflags &= ~X86_EFLAGS_DF; + break; + case 0xfd: /* std */ + ctxt->eflags |= X86_EFLAGS_DF; + break; + default: + goto cannot_emulate; + } + + if (rc != X86EMUL_CONTINUE) + goto done; + +writeback: + if (ctxt->d & SrcWrite) { + BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR); + rc = writeback(ctxt, &ctxt->src); + if (rc != X86EMUL_CONTINUE) + goto done; + } + if (!(ctxt->d & NoWrite)) { + rc = writeback(ctxt, &ctxt->dst); + if (rc != X86EMUL_CONTINUE) + goto done; + } + + /* + * restore dst type in case the decoding will be reused + * (happens for string instruction ) + */ + ctxt->dst.type = saved_dst_type; + + if ((ctxt->d & SrcMask) == SrcSI) + string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src); + + if ((ctxt->d & DstMask) == DstDI) + string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst); + + if (ctxt->rep_prefix && (ctxt->d & String)) { + unsigned int count; + struct read_cache *r = &ctxt->io_read; + if ((ctxt->d & SrcMask) == SrcSI) + count = ctxt->src.count; + else + count = ctxt->dst.count; + register_address_increment(ctxt, VCPU_REGS_RCX, -count); + + if (!string_insn_completed(ctxt)) { + /* + * Re-enter guest when pio read ahead buffer is empty + * or, if it is not used, after each 1024 iteration. + */ + if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) && + (r->end == 0 || r->end != r->pos)) { + /* + * Reset read cache. Usually happens before + * decode, but since instruction is restarted + * we have to do it here. + */ + ctxt->mem_read.end = 0; + writeback_registers(ctxt); + return EMULATION_RESTART; + } + goto done; /* skip rip writeback */ + } + ctxt->eflags &= ~X86_EFLAGS_RF; + } + + ctxt->eip = ctxt->_eip; + +done: + if (rc == X86EMUL_PROPAGATE_FAULT) { + WARN_ON(ctxt->exception.vector > 0x1f); + ctxt->have_exception = true; + } + if (rc == X86EMUL_INTERCEPTED) + return EMULATION_INTERCEPTED; + + if (rc == X86EMUL_CONTINUE) + writeback_registers(ctxt); + + return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; + +twobyte_insn: + switch (ctxt->b) { + case 0x09: /* wbinvd */ + (ctxt->ops->wbinvd)(ctxt); + break; + case 0x08: /* invd */ + case 0x0d: /* GrpP (prefetch) */ + case 0x18: /* Grp16 (prefetch/nop) */ + case 0x1f: /* nop */ + break; + case 0x20: /* mov cr, reg */ + ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg); + break; + case 0x21: /* mov from dr to reg */ + ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val); + break; + case 0x40 ... 0x4f: /* cmov */ + if (test_cc(ctxt->b, ctxt->eflags)) + ctxt->dst.val = ctxt->src.val; + else if (ctxt->op_bytes != 4) + ctxt->dst.type = OP_NONE; /* no writeback */ + break; + case 0x80 ... 0x8f: /* jnz rel, etc*/ + if (test_cc(ctxt->b, ctxt->eflags)) + rc = jmp_rel(ctxt, ctxt->src.val); + break; + case 0x90 ... 0x9f: /* setcc r/m8 */ + ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags); + break; + case 0xb6 ... 0xb7: /* movzx */ + ctxt->dst.bytes = ctxt->op_bytes; + ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val + : (u16) ctxt->src.val; + break; + case 0xbe ... 0xbf: /* movsx */ + ctxt->dst.bytes = ctxt->op_bytes; + ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val : + (s16) ctxt->src.val; + break; + default: + goto cannot_emulate; + } + +threebyte_insn: + + if (rc != X86EMUL_CONTINUE) + goto done; + + goto writeback; + +cannot_emulate: + return EMULATION_FAILED; +} + +void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt) +{ + invalidate_registers(ctxt); +} + +void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt) +{ + writeback_registers(ctxt); +} + +bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt) +{ + if (ctxt->rep_prefix && (ctxt->d & String)) + return false; + + if (ctxt->d & TwoMemOp) + return false; + + return true; +} |