diff options
Diffstat (limited to 'arch/x86/kvm/kvm_cache_regs.h')
-rw-r--r-- | arch/x86/kvm/kvm_cache_regs.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h new file mode 100644 index 0000000000..75eae9c499 --- /dev/null +++ b/arch/x86/kvm/kvm_cache_regs.h @@ -0,0 +1,231 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef ASM_KVM_CACHE_REGS_H +#define ASM_KVM_CACHE_REGS_H + +#include <linux/kvm_host.h> + +#define KVM_POSSIBLE_CR0_GUEST_BITS (X86_CR0_TS | X86_CR0_WP) +#define KVM_POSSIBLE_CR4_GUEST_BITS \ + (X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR \ + | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE) + +#define X86_CR0_PDPTR_BITS (X86_CR0_CD | X86_CR0_NW | X86_CR0_PG) +#define X86_CR4_TLBFLUSH_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP) +#define X86_CR4_PDPTR_BITS (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP) + +static_assert(!(KVM_POSSIBLE_CR0_GUEST_BITS & X86_CR0_PDPTR_BITS)); + +#define BUILD_KVM_GPR_ACCESSORS(lname, uname) \ +static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\ +{ \ + return vcpu->arch.regs[VCPU_REGS_##uname]; \ +} \ +static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu, \ + unsigned long val) \ +{ \ + vcpu->arch.regs[VCPU_REGS_##uname] = val; \ +} +BUILD_KVM_GPR_ACCESSORS(rax, RAX) +BUILD_KVM_GPR_ACCESSORS(rbx, RBX) +BUILD_KVM_GPR_ACCESSORS(rcx, RCX) +BUILD_KVM_GPR_ACCESSORS(rdx, RDX) +BUILD_KVM_GPR_ACCESSORS(rbp, RBP) +BUILD_KVM_GPR_ACCESSORS(rsi, RSI) +BUILD_KVM_GPR_ACCESSORS(rdi, RDI) +#ifdef CONFIG_X86_64 +BUILD_KVM_GPR_ACCESSORS(r8, R8) +BUILD_KVM_GPR_ACCESSORS(r9, R9) +BUILD_KVM_GPR_ACCESSORS(r10, R10) +BUILD_KVM_GPR_ACCESSORS(r11, R11) +BUILD_KVM_GPR_ACCESSORS(r12, R12) +BUILD_KVM_GPR_ACCESSORS(r13, R13) +BUILD_KVM_GPR_ACCESSORS(r14, R14) +BUILD_KVM_GPR_ACCESSORS(r15, R15) +#endif + +/* + * avail dirty + * 0 0 register in VMCS/VMCB + * 0 1 *INVALID* + * 1 0 register in vcpu->arch + * 1 1 register in vcpu->arch, needs to be stored back + */ +static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu, + enum kvm_reg reg) +{ + return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail); +} + +static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu, + enum kvm_reg reg) +{ + return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty); +} + +static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu, + enum kvm_reg reg) +{ + __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail); +} + +static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu, + enum kvm_reg reg) +{ + __set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail); + __set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty); +} + +/* + * kvm_register_test_and_mark_available() is a special snowflake that uses an + * arch bitop directly to avoid the explicit instrumentation that comes with + * the generic bitops. This allows code that cannot be instrumented (noinstr + * functions), e.g. the low level VM-Enter/VM-Exit paths, to cache registers. + */ +static __always_inline bool kvm_register_test_and_mark_available(struct kvm_vcpu *vcpu, + enum kvm_reg reg) +{ + return arch___test_and_set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail); +} + +/* + * The "raw" register helpers are only for cases where the full 64 bits of a + * register are read/written irrespective of current vCPU mode. In other words, + * odds are good you shouldn't be using the raw variants. + */ +static inline unsigned long kvm_register_read_raw(struct kvm_vcpu *vcpu, int reg) +{ + if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS)) + return 0; + + if (!kvm_register_is_available(vcpu, reg)) + static_call(kvm_x86_cache_reg)(vcpu, reg); + + return vcpu->arch.regs[reg]; +} + +static inline void kvm_register_write_raw(struct kvm_vcpu *vcpu, int reg, + unsigned long val) +{ + if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS)) + return; + + vcpu->arch.regs[reg] = val; + kvm_register_mark_dirty(vcpu, reg); +} + +static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu) +{ + return kvm_register_read_raw(vcpu, VCPU_REGS_RIP); +} + +static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val) +{ + kvm_register_write_raw(vcpu, VCPU_REGS_RIP, val); +} + +static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu) +{ + return kvm_register_read_raw(vcpu, VCPU_REGS_RSP); +} + +static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val) +{ + kvm_register_write_raw(vcpu, VCPU_REGS_RSP, val); +} + +static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index) +{ + might_sleep(); /* on svm */ + + if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR)) + static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_PDPTR); + + return vcpu->arch.walk_mmu->pdptrs[index]; +} + +static inline void kvm_pdptr_write(struct kvm_vcpu *vcpu, int index, u64 value) +{ + vcpu->arch.walk_mmu->pdptrs[index] = value; +} + +static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask) +{ + ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS; + if ((tmask & vcpu->arch.cr0_guest_owned_bits) && + !kvm_register_is_available(vcpu, VCPU_EXREG_CR0)) + static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR0); + return vcpu->arch.cr0 & mask; +} + +static __always_inline bool kvm_is_cr0_bit_set(struct kvm_vcpu *vcpu, + unsigned long cr0_bit) +{ + BUILD_BUG_ON(!is_power_of_2(cr0_bit)); + + return !!kvm_read_cr0_bits(vcpu, cr0_bit); +} + +static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu) +{ + return kvm_read_cr0_bits(vcpu, ~0UL); +} + +static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask) +{ + ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS; + if ((tmask & vcpu->arch.cr4_guest_owned_bits) && + !kvm_register_is_available(vcpu, VCPU_EXREG_CR4)) + static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR4); + return vcpu->arch.cr4 & mask; +} + +static __always_inline bool kvm_is_cr4_bit_set(struct kvm_vcpu *vcpu, + unsigned long cr4_bit) +{ + BUILD_BUG_ON(!is_power_of_2(cr4_bit)); + + return !!kvm_read_cr4_bits(vcpu, cr4_bit); +} + +static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu) +{ + if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3)) + static_call(kvm_x86_cache_reg)(vcpu, VCPU_EXREG_CR3); + return vcpu->arch.cr3; +} + +static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu) +{ + return kvm_read_cr4_bits(vcpu, ~0UL); +} + +static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu) +{ + return (kvm_rax_read(vcpu) & -1u) + | ((u64)(kvm_rdx_read(vcpu) & -1u) << 32); +} + +static inline void enter_guest_mode(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hflags |= HF_GUEST_MASK; + vcpu->stat.guest_mode = 1; +} + +static inline void leave_guest_mode(struct kvm_vcpu *vcpu) +{ + vcpu->arch.hflags &= ~HF_GUEST_MASK; + + if (vcpu->arch.load_eoi_exitmap_pending) { + vcpu->arch.load_eoi_exitmap_pending = false; + kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu); + } + + vcpu->stat.guest_mode = 0; +} + +static inline bool is_guest_mode(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.hflags & HF_GUEST_MASK; +} + +#endif |