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KVM: x86 emulator: introduce struct x86_exception to communicate faults

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Introduce a structure that can contain an exception to be passed back
to main kvm code.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Avi Kivity 2010-11-22 17:53:21 +02:00
parent a4ee1ca4a3
commit da9cb575b1
3 changed files with 38 additions and 12 deletions
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11
arch/x86/include/asm/kvm_emulate.h
View File

@ -15,6 +15,12 @@
struct x86_emulate_ctxt;
struct x86_exception {
u8 vector;
bool error_code_valid;
u16 error_code;
};
/*
* x86_emulate_ops:
*
@ -229,9 +235,8 @@ struct x86_emulate_ctxt {
bool perm_ok; /* do not check permissions if true */
int exception; /* exception that happens during emulation or -1 */
u32 error_code; /* error code for exception */
bool error_code_valid;
bool have_exception;
struct x86_exception exception;
/* decode cache */
struct decode_cache decode;

26
arch/x86/kvm/emulate.c
View File

@ -469,9 +469,9 @@ static ulong linear(struct x86_emulate_ctxt *ctxt,
static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
u32 error, bool valid)
{
ctxt->exception = vec;
ctxt->error_code = error;
ctxt->error_code_valid = valid;
ctxt->exception.vector = vec;
ctxt->exception.error_code = error;
ctxt->exception.error_code_valid = valid;
}
static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
@ -3015,23 +3015,27 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
/* LOCK prefix is allowed only with some instructions */
if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
/* Privileged instruction can be executed only in CPL=0 */
if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
@ -3210,6 +3214,7 @@ special_insn:
case 0x8c: /* mov r/m, sreg */
if (c->modrm_reg > VCPU_SREG_GS) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu);
@ -3225,6 +3230,7 @@ special_insn:
if (c->modrm_reg == VCPU_SREG_CS ||
c->modrm_reg > VCPU_SREG_GS) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
@ -3357,6 +3363,7 @@ special_insn:
c->dst.bytes = min(c->dst.bytes, 4u);
if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,
@ -3371,6 +3378,7 @@ special_insn:
if (!emulator_io_permited(ctxt, ops, c->dst.val,
c->src.bytes)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
ops->pio_out_emulated(c->src.bytes, c->dst.val,
@ -3396,6 +3404,7 @@ special_insn:
case 0xfa: /* cli */
if (emulator_bad_iopl(ctxt, ops)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
} else
ctxt->eflags &= ~X86_EFLAGS_IF;
@ -3403,6 +3412,7 @@ special_insn:
case 0xfb: /* sti */
if (emulator_bad_iopl(ctxt, ops)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
} else {
ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
@ -3475,6 +3485,8 @@ writeback:
ctxt->eip = c->eip;
done:
if (rc == X86EMUL_PROPAGATE_FAULT)
ctxt->have_exception = true;
return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
twobyte_insn:
@ -3537,6 +3549,7 @@ twobyte_insn:
break;
case 5: /* not defined */
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
case 7: /* invlpg*/
emulate_invlpg(ctxt->vcpu,
@ -3567,6 +3580,7 @@ twobyte_insn:
case 5 ... 7:
case 9 ... 15:
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
c->dst.val = ops->get_cr(c->modrm_reg, ctxt->vcpu);
@ -3575,6 +3589,7 @@ twobyte_insn:
if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
(c->modrm_reg == 4 || c->modrm_reg == 5)) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
ops->get_dr(c->modrm_reg, &c->dst.val, ctxt->vcpu);
@ -3582,6 +3597,7 @@ twobyte_insn:
case 0x22: /* mov reg, cr */
if (ops->set_cr(c->modrm_reg, c->src.val, ctxt->vcpu)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
c->dst.type = OP_NONE;
@ -3590,6 +3606,7 @@ twobyte_insn:
if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
(c->modrm_reg == 4 || c->modrm_reg == 5)) {
emulate_ud(ctxt);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
@ -3598,6 +3615,7 @@ twobyte_insn:
~0ULL : ~0U), ctxt->vcpu) < 0) {
/* #UD condition is already handled by the code above */
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
@ -3609,6 +3627,7 @@ twobyte_insn:
| ((u64)c->regs[VCPU_REGS_RDX] << 32);
if (ops->set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
}
rc = X86EMUL_CONTINUE;
@ -3617,6 +3636,7 @@ twobyte_insn:
/* rdmsr */
if (ops->get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) {
emulate_gp(ctxt, 0);
rc = X86EMUL_PROPAGATE_FAULT;
goto done;
} else {
c->regs[VCPU_REGS_RAX] = (u32)msr_data;

13
arch/x86/kvm/x86.c
View File

@ -4254,12 +4254,13 @@ static void toggle_interruptibility(struct kvm_vcpu *vcpu, u32 mask)
static void inject_emulated_exception(struct kvm_vcpu *vcpu)
{
struct x86_emulate_ctxt *ctxt = &vcpu->arch.emulate_ctxt;
if (ctxt->exception == PF_VECTOR)
if (ctxt->exception.vector == PF_VECTOR)
kvm_propagate_fault(vcpu);
else if (ctxt->error_code_valid)
kvm_queue_exception_e(vcpu, ctxt->exception, ctxt->error_code);
else if (ctxt->exception.error_code_valid)
kvm_queue_exception_e(vcpu, ctxt->exception.vector,
ctxt->exception.error_code);
else
kvm_queue_exception(vcpu, ctxt->exception);
kvm_queue_exception(vcpu, ctxt->exception.vector);
}
static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
@ -4371,7 +4372,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
if (!(emulation_type & EMULTYPE_NO_DECODE)) {
init_emulate_ctxt(vcpu);
vcpu->arch.emulate_ctxt.interruptibility = 0;
vcpu->arch.emulate_ctxt.exception = -1;
vcpu->arch.emulate_ctxt.have_exception = false;
vcpu->arch.emulate_ctxt.perm_ok = false;
r = x86_decode_insn(&vcpu->arch.emulate_ctxt);
@ -4437,7 +4438,7 @@ restart:
}
done:
if (vcpu->arch.emulate_ctxt.exception >= 0) {
if (vcpu->arch.emulate_ctxt.have_exception) {
inject_emulated_exception(vcpu);
r = EMULATE_DONE;
} else if (vcpu->arch.pio.count) {