KVM: x86: Return UNHANDLABLE on unsupported SYSENTER

Now that KVM injects #UD on "unhandlable" error, it makes better sense to
return such error on sysenter instead of directly injecting #UD to the guest.
This allows to track more easily the unhandlable cases the emulator does not
support.

Signed-off-by: Nadav Amit <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index bf4d23e0f76e56b62ad07074847d5738439bf2d2..dab9b74c29de9fec4cd305739458ab1a6419c0d6 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2358,11 +2358,9 @@ static int em_sysenter(struct x86_emulate_ctxt *ctxt)
            && !vendor_intel(ctxt))
                return emulate_ud(ctxt);
 
-       /* XXX sysenter/sysexit have not been tested in 64bit mode.
-       * Therefore, we inject an #UD.
-       */
+       /* sysenter/sysexit have not been tested in 64bit mode. */
        if (ctxt->mode == X86EMUL_MODE_PROT64)
-               return emulate_ud(ctxt);
+               return X86EMUL_UNHANDLEABLE;
 
        setup_syscalls_segments(ctxt, &cs, &ss);