KVM: emulator: Do not fail on emulation of undefined opcode
Emulation of undefined opcode should inject #UD instead of causing
emulation failure. Do that by moving Undefined flag check to emulation
stage and injection #UD there.
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index ab6fda4..77b56d5 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4383,7 +4383,7 @@
ctxt->intercept = opcode.intercept;
/* Unrecognised? */
- if (ctxt->d == 0 || (ctxt->d & NotImpl) || (ctxt->d & Undefined))
+ if (ctxt->d == 0 || (ctxt->d & NotImpl))
return EMULATION_FAILED;
if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn)
@@ -4521,7 +4521,8 @@
ctxt->mem_read.pos = 0;
- if (ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) {
+ if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) ||
+ (ctxt->d & Undefined)) {
rc = emulate_ud(ctxt);
goto done;
}