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>
This commit is contained in:
Takuya Yoshikawa 2011-05-02 02:30:48 +09:00 committed by Avi Kivity
parent 51187683cb
commit d2f62766d5
1 changed files with 22 additions and 14 deletions

View File

@ -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: