KVM: x86 emulator: re-implementing 'mov AL,moffs' instruction decoding

This patch change to use DstAcc for decoding 'mov AL, moffs'
and introduced SrcAcc for decoding 'mov moffs, AL'.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 286572a5675b03f612bc00202f4140c96cda7177..255473f974abfc0150b0c626a6dc740b10634006 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -70,6 +70,7 @@
 #define SrcSI       (0xa<<4)   /* Source is in the DS:RSI */
 #define SrcImmFAddr (0xb<<4)   /* Source is immediate far address */
 #define SrcMemFAddr (0xc<<4)   /* Source is far address in memory */
+#define SrcAcc      (0xd<<4)   /* Source Accumulator */
 #define SrcMask     (0xf<<4)
 /* Generic ModRM decode. */
 #define ModRM       (1<<8)
@@ -177,8 +178,8 @@ static u32 opcode_table[256] = {
        0, 0, SrcImmFAddr | No64, 0,
        ImplicitOps | Stack, ImplicitOps | Stack, 0, 0,
        /* 0xA0 - 0xA7 */
-       ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs,
-       ByteOp | DstMem | SrcReg | Mov | MemAbs, DstMem | SrcReg | Mov | MemAbs,
+       ByteOp | DstAcc | SrcMem | Mov | MemAbs, DstAcc | SrcMem | Mov | MemAbs,
+       ByteOp | DstMem | SrcAcc | Mov | MemAbs, DstMem | SrcAcc | Mov | MemAbs,
        ByteOp | SrcSI | DstDI | Mov | String, SrcSI | DstDI | Mov | String,
        ByteOp | SrcSI | DstDI | String, SrcSI | DstDI | String,
        /* 0xA8 - 0xAF */
@@ -1186,6 +1187,25 @@ done_prefixes:
                else
                        c->src.val = insn_fetch(u8, 1, c->eip);
                break;
+       case SrcAcc:
+               c->src.type = OP_REG;
+               c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
+               c->src.ptr = &c->regs[VCPU_REGS_RAX];
+               switch (c->src.bytes) {
+                       case 1:
+                               c->src.val = *(u8 *)c->src.ptr;
+                               break;
+                       case 2:
+                               c->src.val = *(u16 *)c->src.ptr;
+                               break;
+                       case 4:
+                               c->src.val = *(u32 *)c->src.ptr;
+                               break;
+                       case 8:
+                               c->src.val = *(u64 *)c->src.ptr;
+                               break;
+               }
+               break;
        case SrcOne:
                c->src.bytes = 1;
                c->src.val = 1;
@@ -2854,13 +2874,7 @@ special_insn:
                if (rc != X86EMUL_CONTINUE)
                        goto done;
                break;
-       case 0xa0 ... 0xa1:     /* mov */
-               c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
-               c->dst.val = c->src.val;
-               break;
-       case 0xa2 ... 0xa3:     /* mov */
-               c->dst.val = (unsigned long)c->regs[VCPU_REGS_RAX];
-               break;
+       case 0xa0 ... 0xa3:     /* mov */
        case 0xa4 ... 0xa5:     /* movs */
                goto mov;
        case 0xa6 ... 0xa7:     /* cmps */