KVM: x86 emulator: Use opcode::execute for LOOP/JCXZ

  LOOP/LOOPcc      : E0-E2
  JCXZ/JECXZ/JRCXZ : E3

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 24 insertions, 11 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index d7df7ba17b89..e9dbbc91ce8e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2824,6 +2824,28 @@ static int em_lmsw(struct x86_emulate_ctxt *ctxt)
         return X86EMUL_CONTINUE;
 }
 
+static int em_loop(struct x86_emulate_ctxt *ctxt)
+{
+        struct decode_cache *c = &ctxt->decode;
+
+        register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
+        if ((address_mask(c, c->regs[VCPU_REGS_RCX]) != 0) &&
+            (c->b == 0xe2 || test_cc(c->b ^ 0x5, ctxt->eflags)))
+                jmp_rel(c, c->src.val);
+
+        return X86EMUL_CONTINUE;
+}
+
+static int em_jcxz(struct x86_emulate_ctxt *ctxt)
+{
+        struct decode_cache *c = &ctxt->decode;
+
+        if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0)
+                jmp_rel(c, c->src.val);
+
+        return X86EMUL_CONTINUE;
+}
+
 static bool valid_cr(int nr)
 {
         switch (nr) {
@@ -3240,7 +3262,8 @@ static struct opcode opcode_table[256] = {
         /* 0xD8 - 0xDF */
         N, N, N, N, N, N, N, N,
         /* 0xE0 - 0xE7 */
-        X4(D(SrcImmByte)),
+        X3(I(SrcImmByte, em_loop)),
+        I(SrcImmByte, em_jcxz),
         D2bvIP(SrcImmUByte | DstAcc, in,  check_perm_in),
         D2bvIP(SrcAcc | DstImmUByte, out, check_perm_out),
         /* 0xE8 - 0xEF */
@@ -3978,16 +4001,6 @@ special_insn:
                 c->src.val = c->regs[VCPU_REGS_RCX];
                 rc = em_grp2(ctxt);
                 break;
-        case 0xe0 ... 0xe2:     /* loop/loopz/loopnz */
-                register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
-                if (address_mask(c, c->regs[VCPU_REGS_RCX]) != 0 &&
-                    (c->b == 0xe2 || test_cc(c->b ^ 0x5, ctxt->eflags)))
-                        jmp_rel(c, c->src.val);
-                break;
-        case 0xe3:      /* jcxz/jecxz/jrcxz */
-                if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0)
-                        jmp_rel(c, c->src.val);
-                break;
         case 0xe4:      /* inb */
         case 0xe5:      /* in */
                 goto do_io_in;