KVM: x86 emulator: cleanup grp3 return value

When x86_emulate_insn() does not know how to emulate instruction it
exits via cannot_emulate label in all cases except when emulating
grp3. Fix that.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 46a7ee3..d696cbd 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1397,7 +1397,6 @@ static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
                               struct x86_emulate_ops *ops)
 {
        struct decode_cache *c = &ctxt->decode;
-       int rc = X86EMUL_CONTINUE;
 
        switch (c->modrm_reg) {
        case 0 ... 1:   /* test */
@@ -1410,11 +1409,9 @@ static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
                emulate_1op("neg", c->dst, ctxt->eflags);
                break;
        default:
-               DPRINTF("Cannot emulate %02x\n", c->b);
-               rc = X86EMUL_UNHANDLEABLE;
-               break;
+               return 0;
        }
-       return rc;
+       return 1;
 }
 
 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
@@ -2374,9 +2371,8 @@ special_insn:
                c->dst.type = OP_NONE;  /* Disable writeback. */
                break;
        case 0xf6 ... 0xf7:     /* Grp3 */
-               rc = emulate_grp3(ctxt, ops);
-               if (rc != X86EMUL_CONTINUE)
-                       goto done;
+               if (!emulate_grp3(ctxt, ops))
+                       goto cannot_emulate;
                break;
        case 0xf8: /* clc */
                ctxt->eflags &= ~EFLG_CF;