Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 696 insertions, 0 deletions

diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c
new file mode 100644
index 0000000000..ce8de3fa47
--- /dev/null
+++ b/arch/loongarch/kvm/exit.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/preempt.h>
+#include <linux/vmalloc.h>
+#include <asm/fpu.h>
+#include <asm/inst.h>
+#include <asm/loongarch.h>
+#include <asm/mmzone.h>
+#include <asm/numa.h>
+#include <asm/time.h>
+#include <asm/tlb.h>
+#include <asm/kvm_csr.h>
+#include <asm/kvm_vcpu.h>
+#include "trace.h"
+
+static unsigned long kvm_emu_read_csr(struct kvm_vcpu *vcpu, int csrid)
+{
+	unsigned long val = 0;
+	struct loongarch_csrs *csr = vcpu->arch.csr;
+
+	/*
+	 * From LoongArch Reference Manual Volume 1 Chapter 4.2.1
+	 * For undefined CSR id, return value is 0
+	 */
+	if (get_gcsr_flag(csrid) & SW_GCSR)
+		val = kvm_read_sw_gcsr(csr, csrid);
+	else
+		pr_warn_once("Unsupported csrrd 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
+
+	return val;
+}
+
+static unsigned long kvm_emu_write_csr(struct kvm_vcpu *vcpu, int csrid, unsigned long val)
+{
+	unsigned long old = 0;
+	struct loongarch_csrs *csr = vcpu->arch.csr;
+
+	if (get_gcsr_flag(csrid) & SW_GCSR) {
+		old = kvm_read_sw_gcsr(csr, csrid);
+		kvm_write_sw_gcsr(csr, csrid, val);
+	} else
+		pr_warn_once("Unsupported csrwr 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
+
+	return old;
+}
+
+static unsigned long kvm_emu_xchg_csr(struct kvm_vcpu *vcpu, int csrid,
+				unsigned long csr_mask, unsigned long val)
+{
+	unsigned long old = 0;
+	struct loongarch_csrs *csr = vcpu->arch.csr;
+
+	if (get_gcsr_flag(csrid) & SW_GCSR) {
+		old = kvm_read_sw_gcsr(csr, csrid);
+		val = (old & ~csr_mask) | (val & csr_mask);
+		kvm_write_sw_gcsr(csr, csrid, val);
+		old = old & csr_mask;
+	} else
+		pr_warn_once("Unsupported csrxchg 0x%x with pc %lx\n", csrid, vcpu->arch.pc);
+
+	return old;
+}
+
+static int kvm_handle_csr(struct kvm_vcpu *vcpu, larch_inst inst)
+{
+	unsigned int rd, rj, csrid;
+	unsigned long csr_mask, val = 0;
+
+	/*
+	 * CSR value mask imm
+	 * rj = 0 means csrrd
+	 * rj = 1 means csrwr
+	 * rj != 0,1 means csrxchg
+	 */
+	rd = inst.reg2csr_format.rd;
+	rj = inst.reg2csr_format.rj;
+	csrid = inst.reg2csr_format.csr;
+
+	/* Process CSR ops */
+	switch (rj) {
+	case 0: /* process csrrd */
+		val = kvm_emu_read_csr(vcpu, csrid);
+		vcpu->arch.gprs[rd] = val;
+		break;
+	case 1: /* process csrwr */
+		val = vcpu->arch.gprs[rd];
+		val = kvm_emu_write_csr(vcpu, csrid, val);
+		vcpu->arch.gprs[rd] = val;
+		break;
+	default: /* process csrxchg */
+		val = vcpu->arch.gprs[rd];
+		csr_mask = vcpu->arch.gprs[rj];
+		val = kvm_emu_xchg_csr(vcpu, csrid, csr_mask, val);
+		vcpu->arch.gprs[rd] = val;
+	}
+
+	return EMULATE_DONE;
+}
+
+int kvm_emu_iocsr(larch_inst inst, struct kvm_run *run, struct kvm_vcpu *vcpu)
+{
+	int ret;
+	unsigned long val;
+	u32 addr, rd, rj, opcode;
+
+	/*
+	 * Each IOCSR with different opcode
+	 */
+	rd = inst.reg2_format.rd;
+	rj = inst.reg2_format.rj;
+	opcode = inst.reg2_format.opcode;
+	addr = vcpu->arch.gprs[rj];
+	ret = EMULATE_DO_IOCSR;
+	run->iocsr_io.phys_addr = addr;
+	run->iocsr_io.is_write = 0;
+
+	/* LoongArch is Little endian */
+	switch (opcode) {
+	case iocsrrdb_op:
+		run->iocsr_io.len = 1;
+		break;
+	case iocsrrdh_op:
+		run->iocsr_io.len = 2;
+		break;
+	case iocsrrdw_op:
+		run->iocsr_io.len = 4;
+		break;
+	case iocsrrdd_op:
+		run->iocsr_io.len = 8;
+		break;
+	case iocsrwrb_op:
+		run->iocsr_io.len = 1;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrh_op:
+		run->iocsr_io.len = 2;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrw_op:
+		run->iocsr_io.len = 4;
+		run->iocsr_io.is_write = 1;
+		break;
+	case iocsrwrd_op:
+		run->iocsr_io.len = 8;
+		run->iocsr_io.is_write = 1;
+		break;
+	default:
+		ret = EMULATE_FAIL;
+		break;
+	}
+
+	if (ret == EMULATE_DO_IOCSR) {
+		if (run->iocsr_io.is_write) {
+			val = vcpu->arch.gprs[rd];
+			memcpy(run->iocsr_io.data, &val, run->iocsr_io.len);
+		}
+		vcpu->arch.io_gpr = rd;
+	}
+
+	return ret;
+}
+
+int kvm_complete_iocsr_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	enum emulation_result er = EMULATE_DONE;
+	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
+
+	switch (run->iocsr_io.len) {
+	case 1:
+		*gpr = *(s8 *)run->iocsr_io.data;
+		break;
+	case 2:
+		*gpr = *(s16 *)run->iocsr_io.data;
+		break;
+	case 4:
+		*gpr = *(s32 *)run->iocsr_io.data;
+		break;
+	case 8:
+		*gpr = *(s64 *)run->iocsr_io.data;
+		break;
+	default:
+		kvm_err("Bad IOCSR length: %d, addr is 0x%lx\n",
+				run->iocsr_io.len, vcpu->arch.badv);
+		er = EMULATE_FAIL;
+		break;
+	}
+
+	return er;
+}
+
+int kvm_emu_idle(struct kvm_vcpu *vcpu)
+{
+	++vcpu->stat.idle_exits;
+	trace_kvm_exit_idle(vcpu, KVM_TRACE_EXIT_IDLE);
+
+	if (!kvm_arch_vcpu_runnable(vcpu)) {
+		/*
+		 * Switch to the software timer before halt-polling/blocking as
+		 * the guest's timer may be a break event for the vCPU, and the
+		 * hypervisor timer runs only when the CPU is in guest mode.
+		 * Switch before halt-polling so that KVM recognizes an expired
+		 * timer before blocking.
+		 */
+		kvm_save_timer(vcpu);
+		kvm_vcpu_block(vcpu);
+	}
+
+	return EMULATE_DONE;
+}
+
+static int kvm_trap_handle_gspr(struct kvm_vcpu *vcpu)
+{
+	int rd, rj;
+	unsigned int index;
+	unsigned long curr_pc;
+	larch_inst inst;
+	enum emulation_result er = EMULATE_DONE;
+	struct kvm_run *run = vcpu->run;
+
+	/* Fetch the instruction */
+	inst.word = vcpu->arch.badi;
+	curr_pc = vcpu->arch.pc;
+	update_pc(&vcpu->arch);
+
+	trace_kvm_exit_gspr(vcpu, inst.word);
+	er = EMULATE_FAIL;
+	switch (((inst.word >> 24) & 0xff)) {
+	case 0x0: /* CPUCFG GSPR */
+		if (inst.reg2_format.opcode == 0x1B) {
+			rd = inst.reg2_format.rd;
+			rj = inst.reg2_format.rj;
+			++vcpu->stat.cpucfg_exits;
+			index = vcpu->arch.gprs[rj];
+			er = EMULATE_DONE;
+			/*
+			 * By LoongArch Reference Manual 2.2.10.5
+			 * return value is 0 for undefined cpucfg index
+			 */
+			if (index < KVM_MAX_CPUCFG_REGS)
+				vcpu->arch.gprs[rd] = vcpu->arch.cpucfg[index];
+			else
+				vcpu->arch.gprs[rd] = 0;
+		}
+		break;
+	case 0x4: /* CSR{RD,WR,XCHG} GSPR */
+		er = kvm_handle_csr(vcpu, inst);
+		break;
+	case 0x6: /* Cache, Idle and IOCSR GSPR */
+		switch (((inst.word >> 22) & 0x3ff)) {
+		case 0x18: /* Cache GSPR */
+			er = EMULATE_DONE;
+			trace_kvm_exit_cache(vcpu, KVM_TRACE_EXIT_CACHE);
+			break;
+		case 0x19: /* Idle/IOCSR GSPR */
+			switch (((inst.word >> 15) & 0x1ffff)) {
+			case 0xc90: /* IOCSR GSPR */
+				er = kvm_emu_iocsr(inst, run, vcpu);
+				break;
+			case 0xc91: /* Idle GSPR */
+				er = kvm_emu_idle(vcpu);
+				break;
+			default:
+				er = EMULATE_FAIL;
+				break;
+			}
+			break;
+		default:
+			er = EMULATE_FAIL;
+			break;
+		}
+		break;
+	default:
+		er = EMULATE_FAIL;
+		break;
+	}
+
+	/* Rollback PC only if emulation was unsuccessful */
+	if (er == EMULATE_FAIL) {
+		kvm_err("[%#lx]%s: unsupported gspr instruction 0x%08x\n",
+			curr_pc, __func__, inst.word);
+
+		kvm_arch_vcpu_dump_regs(vcpu);
+		vcpu->arch.pc = curr_pc;
+	}
+
+	return er;
+}
+
+/*
+ * Trigger GSPR:
+ * 1) Execute CPUCFG instruction;
+ * 2) Execute CACOP/IDLE instructions;
+ * 3) Access to unimplemented CSRs/IOCSRs.
+ */
+static int kvm_handle_gspr(struct kvm_vcpu *vcpu)
+{
+	int ret = RESUME_GUEST;
+	enum emulation_result er = EMULATE_DONE;
+
+	er = kvm_trap_handle_gspr(vcpu);
+
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else if (er == EMULATE_DO_MMIO) {
+		vcpu->run->exit_reason = KVM_EXIT_MMIO;
+		ret = RESUME_HOST;
+	} else if (er == EMULATE_DO_IOCSR) {
+		vcpu->run->exit_reason = KVM_EXIT_LOONGARCH_IOCSR;
+		ret = RESUME_HOST;
+	} else {
+		kvm_queue_exception(vcpu, EXCCODE_INE, 0);
+		ret = RESUME_GUEST;
+	}
+
+	return ret;
+}
+
+int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
+{
+	int ret;
+	unsigned int op8, opcode, rd;
+	struct kvm_run *run = vcpu->run;
+
+	run->mmio.phys_addr = vcpu->arch.badv;
+	vcpu->mmio_needed = 2;	/* signed */
+	op8 = (inst.word >> 24) & 0xff;
+	ret = EMULATE_DO_MMIO;
+
+	switch (op8) {
+	case 0x24 ... 0x27:	/* ldptr.w/d process */
+		rd = inst.reg2i14_format.rd;
+		opcode = inst.reg2i14_format.opcode;
+
+		switch (opcode) {
+		case ldptrw_op:
+			run->mmio.len = 4;
+			break;
+		case ldptrd_op:
+			run->mmio.len = 8;
+			break;
+		default:
+			break;
+		}
+		break;
+	case 0x28 ... 0x2e:	/* ld.b/h/w/d, ld.bu/hu/wu process */
+		rd = inst.reg2i12_format.rd;
+		opcode = inst.reg2i12_format.opcode;
+
+		switch (opcode) {
+		case ldb_op:
+			run->mmio.len = 1;
+			break;
+		case ldbu_op:
+			vcpu->mmio_needed = 1;	/* unsigned */
+			run->mmio.len = 1;
+			break;
+		case ldh_op:
+			run->mmio.len = 2;
+			break;
+		case ldhu_op:
+			vcpu->mmio_needed = 1;	/* unsigned */
+			run->mmio.len = 2;
+			break;
+		case ldw_op:
+			run->mmio.len = 4;
+			break;
+		case ldwu_op:
+			vcpu->mmio_needed = 1;	/* unsigned */
+			run->mmio.len = 4;
+			break;
+		case ldd_op:
+			run->mmio.len = 8;
+			break;
+		default:
+			ret = EMULATE_FAIL;
+			break;
+		}
+		break;
+	case 0x38:	/* ldx.b/h/w/d, ldx.bu/hu/wu process */
+		rd = inst.reg3_format.rd;
+		opcode = inst.reg3_format.opcode;
+
+		switch (opcode) {
+		case ldxb_op:
+			run->mmio.len = 1;
+			break;
+		case ldxbu_op:
+			run->mmio.len = 1;
+			vcpu->mmio_needed = 1;	/* unsigned */
+			break;
+		case ldxh_op:
+			run->mmio.len = 2;
+			break;
+		case ldxhu_op:
+			run->mmio.len = 2;
+			vcpu->mmio_needed = 1;	/* unsigned */
+			break;
+		case ldxw_op:
+			run->mmio.len = 4;
+			break;
+		case ldxwu_op:
+			run->mmio.len = 4;
+			vcpu->mmio_needed = 1;	/* unsigned */
+			break;
+		case ldxd_op:
+			run->mmio.len = 8;
+			break;
+		default:
+			ret = EMULATE_FAIL;
+			break;
+		}
+		break;
+	default:
+		ret = EMULATE_FAIL;
+	}
+
+	if (ret == EMULATE_DO_MMIO) {
+		/* Set for kvm_complete_mmio_read() use */
+		vcpu->arch.io_gpr = rd;
+		run->mmio.is_write = 0;
+		vcpu->mmio_is_write = 0;
+	} else {
+		kvm_err("Read not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
+			inst.word, vcpu->arch.pc, vcpu->arch.badv);
+		kvm_arch_vcpu_dump_regs(vcpu);
+		vcpu->mmio_needed = 0;
+	}
+
+	return ret;
+}
+
+int kvm_complete_mmio_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	enum emulation_result er = EMULATE_DONE;
+	unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
+
+	/* Update with new PC */
+	update_pc(&vcpu->arch);
+	switch (run->mmio.len) {
+	case 1:
+		if (vcpu->mmio_needed == 2)
+			*gpr = *(s8 *)run->mmio.data;
+		else
+			*gpr = *(u8 *)run->mmio.data;
+		break;
+	case 2:
+		if (vcpu->mmio_needed == 2)
+			*gpr = *(s16 *)run->mmio.data;
+		else
+			*gpr = *(u16 *)run->mmio.data;
+		break;
+	case 4:
+		if (vcpu->mmio_needed == 2)
+			*gpr = *(s32 *)run->mmio.data;
+		else
+			*gpr = *(u32 *)run->mmio.data;
+		break;
+	case 8:
+		*gpr = *(s64 *)run->mmio.data;
+		break;
+	default:
+		kvm_err("Bad MMIO length: %d, addr is 0x%lx\n",
+				run->mmio.len, vcpu->arch.badv);
+		er = EMULATE_FAIL;
+		break;
+	}
+
+	return er;
+}
+
+int kvm_emu_mmio_write(struct kvm_vcpu *vcpu, larch_inst inst)
+{
+	int ret;
+	unsigned int rd, op8, opcode;
+	unsigned long curr_pc, rd_val = 0;
+	struct kvm_run *run = vcpu->run;
+	void *data = run->mmio.data;
+
+	/*
+	 * Update PC and hold onto current PC in case there is
+	 * an error and we want to rollback the PC
+	 */
+	curr_pc = vcpu->arch.pc;
+	update_pc(&vcpu->arch);
+
+	op8 = (inst.word >> 24) & 0xff;
+	run->mmio.phys_addr = vcpu->arch.badv;
+	ret = EMULATE_DO_MMIO;
+	switch (op8) {
+	case 0x24 ... 0x27:	/* stptr.w/d process */
+		rd = inst.reg2i14_format.rd;
+		opcode = inst.reg2i14_format.opcode;
+
+		switch (opcode) {
+		case stptrw_op:
+			run->mmio.len = 4;
+			*(unsigned int *)data = vcpu->arch.gprs[rd];
+			break;
+		case stptrd_op:
+			run->mmio.len = 8;
+			*(unsigned long *)data = vcpu->arch.gprs[rd];
+			break;
+		default:
+			ret = EMULATE_FAIL;
+			break;
+		}
+		break;
+	case 0x28 ... 0x2e:	/* st.b/h/w/d  process */
+		rd = inst.reg2i12_format.rd;
+		opcode = inst.reg2i12_format.opcode;
+		rd_val = vcpu->arch.gprs[rd];
+
+		switch (opcode) {
+		case stb_op:
+			run->mmio.len = 1;
+			*(unsigned char *)data = rd_val;
+			break;
+		case sth_op:
+			run->mmio.len = 2;
+			*(unsigned short *)data = rd_val;
+			break;
+		case stw_op:
+			run->mmio.len = 4;
+			*(unsigned int *)data = rd_val;
+			break;
+		case std_op:
+			run->mmio.len = 8;
+			*(unsigned long *)data = rd_val;
+			break;
+		default:
+			ret = EMULATE_FAIL;
+			break;
+		}
+		break;
+	case 0x38:	/* stx.b/h/w/d process */
+		rd = inst.reg3_format.rd;
+		opcode = inst.reg3_format.opcode;
+
+		switch (opcode) {
+		case stxb_op:
+			run->mmio.len = 1;
+			*(unsigned char *)data = vcpu->arch.gprs[rd];
+			break;
+		case stxh_op:
+			run->mmio.len = 2;
+			*(unsigned short *)data = vcpu->arch.gprs[rd];
+			break;
+		case stxw_op:
+			run->mmio.len = 4;
+			*(unsigned int *)data = vcpu->arch.gprs[rd];
+			break;
+		case stxd_op:
+			run->mmio.len = 8;
+			*(unsigned long *)data = vcpu->arch.gprs[rd];
+			break;
+		default:
+			ret = EMULATE_FAIL;
+			break;
+		}
+		break;
+	default:
+		ret = EMULATE_FAIL;
+	}
+
+	if (ret == EMULATE_DO_MMIO) {
+		run->mmio.is_write = 1;
+		vcpu->mmio_needed = 1;
+		vcpu->mmio_is_write = 1;
+	} else {
+		vcpu->arch.pc = curr_pc;
+		kvm_err("Write not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
+			inst.word, vcpu->arch.pc, vcpu->arch.badv);
+		kvm_arch_vcpu_dump_regs(vcpu);
+		/* Rollback PC if emulation was unsuccessful */
+	}
+
+	return ret;
+}
+
+static int kvm_handle_rdwr_fault(struct kvm_vcpu *vcpu, bool write)
+{
+	int ret;
+	larch_inst inst;
+	enum emulation_result er = EMULATE_DONE;
+	struct kvm_run *run = vcpu->run;
+	unsigned long badv = vcpu->arch.badv;
+
+	ret = kvm_handle_mm_fault(vcpu, badv, write);
+	if (ret) {
+		/* Treat as MMIO */
+		inst.word = vcpu->arch.badi;
+		if (write) {
+			er = kvm_emu_mmio_write(vcpu, inst);
+		} else {
+			/* A code fetch fault doesn't count as an MMIO */
+			if (kvm_is_ifetch_fault(&vcpu->arch)) {
+				kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEF);
+				return RESUME_GUEST;
+			}
+
+			er = kvm_emu_mmio_read(vcpu, inst);
+		}
+	}
+
+	if (er == EMULATE_DONE) {
+		ret = RESUME_GUEST;
+	} else if (er == EMULATE_DO_MMIO) {
+		run->exit_reason = KVM_EXIT_MMIO;
+		ret = RESUME_HOST;
+	} else {
+		kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEM);
+		ret = RESUME_GUEST;
+	}
+
+	return ret;
+}
+
+static int kvm_handle_read_fault(struct kvm_vcpu *vcpu)
+{
+	return kvm_handle_rdwr_fault(vcpu, false);
+}
+
+static int kvm_handle_write_fault(struct kvm_vcpu *vcpu)
+{
+	return kvm_handle_rdwr_fault(vcpu, true);
+}
+
+/**
+ * kvm_handle_fpu_disabled() - Guest used fpu however it is disabled at host
+ * @vcpu:	Virtual CPU context.
+ *
+ * Handle when the guest attempts to use fpu which hasn't been allowed
+ * by the root context.
+ */
+static int kvm_handle_fpu_disabled(struct kvm_vcpu *vcpu)
+{
+	struct kvm_run *run = vcpu->run;
+
+	/*
+	 * If guest FPU not present, the FPU operation should have been
+	 * treated as a reserved instruction!
+	 * If FPU already in use, we shouldn't get this at all.
+	 */
+	if (WARN_ON(vcpu->arch.aux_inuse & KVM_LARCH_FPU)) {
+		kvm_err("%s internal error\n", __func__);
+		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		return RESUME_HOST;
+	}
+
+	kvm_own_fpu(vcpu);
+
+	return RESUME_GUEST;
+}
+
+/*
+ * LoongArch KVM callback handling for unimplemented guest exiting
+ */
+static int kvm_fault_ni(struct kvm_vcpu *vcpu)
+{
+	unsigned int ecode, inst;
+	unsigned long estat, badv;
+
+	/* Fetch the instruction */
+	inst = vcpu->arch.badi;
+	badv = vcpu->arch.badv;
+	estat = vcpu->arch.host_estat;
+	ecode = (estat & CSR_ESTAT_EXC) >> CSR_ESTAT_EXC_SHIFT;
+	kvm_err("ECode: %d PC=%#lx Inst=0x%08x BadVaddr=%#lx ESTAT=%#lx\n",
+			ecode, vcpu->arch.pc, inst, badv, read_gcsr_estat());
+	kvm_arch_vcpu_dump_regs(vcpu);
+	kvm_queue_exception(vcpu, EXCCODE_INE, 0);
+
+	return RESUME_GUEST;
+}
+
+static exit_handle_fn kvm_fault_tables[EXCCODE_INT_START] = {
+	[0 ... EXCCODE_INT_START - 1]	= kvm_fault_ni,
+	[EXCCODE_TLBI]			= kvm_handle_read_fault,
+	[EXCCODE_TLBL]			= kvm_handle_read_fault,
+	[EXCCODE_TLBS]			= kvm_handle_write_fault,
+	[EXCCODE_TLBM]			= kvm_handle_write_fault,
+	[EXCCODE_FPDIS]			= kvm_handle_fpu_disabled,
+	[EXCCODE_GSPR]			= kvm_handle_gspr,
+};
+
+int kvm_handle_fault(struct kvm_vcpu *vcpu, int fault)
+{
+	return kvm_fault_tables[fault](vcpu);
+}