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>
diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
index 470ac54..1dbd0c7 100644
--- a/arch/x86/include/asm/kvm_emulate.h
+++ b/arch/x86/include/asm/kvm_emulate.h
@@ -331,6 +331,7 @@
#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,
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index c2260e5..a2c31e5 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3592,6 +3592,9 @@
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:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 36786bb..99bed74 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4516,6 +4516,9 @@
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;