KVM: x86 emulator: Don't write-back cpu-state on X86EMUL_INTERCEPTED

This patch prevents the changed CPU state to be written back
when the emulator detected that the instruction was
intercepted by the guest.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Joerg Roedel 2011-04-04 12:39:24 +02:00 committed by Avi Kivity
parent 3c6e276f22
commit 775fde8648
3 changed files with 7 additions and 0 deletions

View file

@ -331,6 +331,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len);
#define EMULATION_FAILED -1
#define EMULATION_OK 0
#define EMULATION_RESTART 1
#define EMULATION_INTERCEPTED 2
int x86_emulate_insn(struct x86_emulate_ctxt *ctxt);
int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
u16 tss_selector, int reason,

View file

@ -3592,6 +3592,9 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
done:
if (rc == X86EMUL_PROPAGATE_FAULT)
ctxt->have_exception = true;
if (rc == X86EMUL_INTERCEPTED)
return EMULATION_INTERCEPTED;
return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
twobyte_insn:

View file

@ -4516,6 +4516,9 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
restart:
r = x86_emulate_insn(&vcpu->arch.emulate_ctxt);
if (r == EMULATION_INTERCEPTED)
return EMULATE_DONE;
if (r == EMULATION_FAILED) {
if (reexecute_instruction(vcpu, cr2))
return EMULATE_DONE;