KVM: x86 emulator: Make jmp far emulation into a separate function

We introduce em_jmp_far().

We also call this from em_grp45() to stop treating modrm_reg == 5 case
separately in the group 5 emulation.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d9ebf69..d6e2477 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1687,6 +1687,23 @@ static inline int emulate_iret(struct x86_emulate_ctxt *ctxt,
        }
 }
 
+static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
+{
+       struct decode_cache *c = &ctxt->decode;
+       int rc;
+       unsigned short sel;
+
+       memcpy(&sel, c->src.valptr + c->op_bytes, 2);
+
+       rc = load_segment_descriptor(ctxt, ctxt->ops, sel, VCPU_SREG_CS);
+       if (rc != X86EMUL_CONTINUE)
+               return rc;
+
+       c->eip = 0;
+       memcpy(&c->eip, c->src.valptr, c->op_bytes);
+       return X86EMUL_CONTINUE;
+}
+
 static int em_grp1a(struct x86_emulate_ctxt *ctxt)
 {
        struct decode_cache *c = &ctxt->decode;
@@ -1786,6 +1803,9 @@ static int em_grp45(struct x86_emulate_ctxt *ctxt)
        case 4: /* jmp abs */
                c->eip = c->src.val;
                break;
+       case 5: /* jmp far */
+               rc = em_jmp_far(ctxt);
+               break;
        case 6: /* push */
                rc = em_push(ctxt);
                break;
@@ -3997,19 +4017,9 @@ special_insn:
        }
        case 0xe9: /* jmp rel */
                goto jmp;
-       case 0xea: { /* jmp far */
-               unsigned short sel;
-       jump_far:
-               memcpy(&sel, c->src.valptr + c->op_bytes, 2);
-
-               rc = load_segment_descriptor(ctxt, ops, sel, VCPU_SREG_CS);
-               if (rc != X86EMUL_CONTINUE)
-                       goto done;
-
-               c->eip = 0;
-               memcpy(&c->eip, c->src.valptr, c->op_bytes);
+       case 0xea: /* jmp far */
+               rc = em_jmp_far(ctxt);
                break;
-       }
        case 0xeb:
              jmp:              /* jmp rel short */
                jmp_rel(c, c->src.val);
@@ -4073,8 +4083,6 @@ special_insn:
                rc = em_grp45(ctxt);
                break;
        case 0xff: /* Grp5 */
-               if (c->modrm_reg == 5)
-                       goto jump_far;
                rc = em_grp45(ctxt);
                break;
        default: