KVM: x86 emulator: convert group 3 instructions to direct decode

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 48 insertions, 34 deletions

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index af06539369b4..ed819bdf475d 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1663,37 +1663,49 @@ static int em_grp2(struct x86_emulate_ctxt *ctxt)
         return X86EMUL_CONTINUE;
 }
 
-static int em_grp3(struct x86_emulate_ctxt *ctxt)
+static int em_not(struct x86_emulate_ctxt *ctxt)
+{
+        ctxt->dst.val = ~ctxt->dst.val;
+        return X86EMUL_CONTINUE;
+}
+
+static int em_neg(struct x86_emulate_ctxt *ctxt)
+{
+        emulate_1op(ctxt, "neg");
+        return X86EMUL_CONTINUE;
+}
+
+static int em_mul_ex(struct x86_emulate_ctxt *ctxt)
+{
+        u8 ex = 0;
+
+        emulate_1op_rax_rdx(ctxt, "mul", ex);
+        return X86EMUL_CONTINUE;
+}
+
+static int em_imul_ex(struct x86_emulate_ctxt *ctxt)
+{
+        u8 ex = 0;
+
+        emulate_1op_rax_rdx(ctxt, "imul", ex);
+        return X86EMUL_CONTINUE;
+}
+
+static int em_div_ex(struct x86_emulate_ctxt *ctxt)
 {
         u8 de = 0;
 
-        switch (ctxt->modrm_reg) {
-        case 0 ... 1:   /* test */
-                emulate_2op_SrcV(ctxt, "test");
-                /* Disable writeback. */
-                ctxt->dst.type = OP_NONE;
-                break;
-        case 2: /* not */
-                ctxt->dst.val = ~ctxt->dst.val;
-                break;
-        case 3: /* neg */
-                emulate_1op(ctxt, "neg");
-                break;
-        case 4: /* mul */
-                emulate_1op_rax_rdx(ctxt, "mul", de);
-                break;
-        case 5: /* imul */
-                emulate_1op_rax_rdx(ctxt, "imul", de);
-                break;
-        case 6: /* div */
-                emulate_1op_rax_rdx(ctxt, "div", de);
-                break;
-        case 7: /* idiv */
-                emulate_1op_rax_rdx(ctxt, "idiv", de);
-                break;
-        default:
-                return X86EMUL_UNHANDLEABLE;
-        }
+        emulate_1op_rax_rdx(ctxt, "div", de);
+        if (de)
+                return emulate_de(ctxt);
+        return X86EMUL_CONTINUE;
+}
+
+static int em_idiv_ex(struct x86_emulate_ctxt *ctxt)
+{
+        u8 de = 0;
+
+        emulate_1op_rax_rdx(ctxt, "idiv", de);
         if (de)
                 return emulate_de(ctxt);
         return X86EMUL_CONTINUE;
@@ -2989,9 +3001,14 @@ static struct opcode group1A[] = {
 };
 
 static struct opcode group3[] = {
-        D(DstMem | SrcImm | ModRM), D(DstMem | SrcImm | ModRM),
-        D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock),
-        X4(D(SrcMem | ModRM)),
+        I(DstMem | SrcImm | ModRM, em_test),
+        I(DstMem | SrcImm | ModRM, em_test),
+        I(DstMem | SrcNone | ModRM | Lock, em_not),
+        I(DstMem | SrcNone | ModRM | Lock, em_neg),
+        I(SrcMem | ModRM, em_mul_ex),
+        I(SrcMem | ModRM, em_imul_ex),
+        I(SrcMem | ModRM, em_div_ex),
+        I(SrcMem | ModRM, em_idiv_ex),
 };
 
 static struct opcode group4[] = {
@@ -3917,9 +3934,6 @@ special_insn:
                 /* complement carry flag from eflags reg */
                 ctxt->eflags ^= EFLG_CF;
                 break;
-        case 0xf6 ... 0xf7:     /* Grp3 */
-                rc = em_grp3(ctxt);
-                break;
         case 0xf8: /* clc */
                 ctxt->eflags &= ~EFLG_CF;
                 break;