KVM: x86 emulator: Implement emulation of instruction: inc & dec

Instructions:
	inc r16/r32 (opcode 0x40-0x47)
	dec r16/r32 (opcode 0x48-0x4f)

Signed-off-by: Nitin A Kamble <nitin.a.kamble@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 18 insertions, 2 deletions

diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index 75fd23bade9c..988c6498640f 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -96,8 +96,12 @@ static u8 opcode_table[256] = {
         ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
         ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
         0, 0, 0, 0,
-        /* 0x40 - 0x4F */
-        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        /* 0x40 - 0x47 */
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
+        /* 0x48 - 0x4F */
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
+        ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
         /* 0x50 - 0x57 */
         ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
         ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
@@ -1376,6 +1380,18 @@ special_insn:
         if (c->twobyte)
                 goto twobyte_special_insn;
         switch (c->b) {
+        case 0x40 ... 0x47: /* inc r16/r32 */
+                c->dst.bytes = c->op_bytes;
+                c->dst.ptr = (unsigned long *)&c->regs[c->b & 0x7];
+                c->dst.val = *c->dst.ptr;
+                emulate_1op("inc", c->dst, ctxt->eflags);
+                break;
+        case 0x48 ... 0x4f: /* dec r16/r32 */
+                c->dst.bytes = c->op_bytes;
+                c->dst.ptr = (unsigned long *)&c->regs[c->b & 0x7];
+                c->dst.val = *c->dst.ptr;
+                emulate_1op("dec", c->dst, ctxt->eflags);
+                break;
         case 0x50 ... 0x57:  /* push reg */
                 if (c->op_bytes == 2)
                         c->src.val = (u16) c->regs[c->b & 0x7];