KVM: inject #UD in 64bit mode from instruction that are not valid there

Some instruction are obsolete in a long mode. Inject #UD.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 4dade6ac082..96d4bef06e1 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1015,11 +1015,6 @@ done_prefixes:
                 }
         }
 
-        if (mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
-                kvm_report_emulation_failure(ctxt->vcpu, "invalid x86/64 instruction");
-                return -1;
-        }
-
         if (c->d & Group) {
                 group = c->d & GroupMask;
                 c->modrm = insn_fetch(u8, 1, c->eip);
@@ -1828,6 +1823,11 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
         memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
         saved_eip = c->eip;
 
+        if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
+                kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+                goto done;
+        }
+
         /* LOCK prefix is allowed only with some instructions */
         if (c->lock_prefix && !(c->d & Lock)) {
                 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);