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>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 4dade6a..96d4bef 100644 (file)
--- 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);