KVM: x86 emulator: Remove byte-sized MOVSX/MOVZX hack

[cascardo/linux.git] / arch / x86 / kvm / emulate.c

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 0982507..6eaedac 100644 (file)
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -57,6 +57,7 @@
 #define OpDS              23ull  /* DS */
 #define OpFS              24ull  /* FS */
 #define OpGS              25ull  /* GS */
+#define OpMem8            26ull  /* 8-bit zero extended memory operand */
 
 #define OpBits             5  /* Width of operand field */
 #define OpMask             ((1ull << OpBits) - 1)
@@ -101,6 +102,7 @@
 #define SrcAcc      (OpAcc << SrcShift)
 #define SrcImmU16   (OpImmU16 << SrcShift)
 #define SrcDX       (OpDX << SrcShift)
+#define SrcMem8     (OpMem8 << SrcShift)
 #define SrcMask     (OpMask << SrcShift)
 #define BitOp       (1<<11)
 #define MemAbs      (1<<12)      /* Memory operand is absolute displacement */
@@ -858,8 +860,7 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
 }
 
 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
-                                   struct operand *op,
-                                   int inhibit_bytereg)
+                                   struct operand *op)
 {
        unsigned reg = ctxt->modrm_reg;
        int highbyte_regs = ctxt->rex_prefix == 0;
@@ -876,7 +877,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
        }
 
        op->type = OP_REG;
-       if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
+       if (ctxt->d & ByteOp) {
                op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
                op->bytes = 1;
        } else {
@@ -3514,13 +3515,13 @@ static struct opcode twobyte_table[256] = {
        I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
        I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
        I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
-       D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+       D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
        /* 0xB8 - 0xBF */
        N, N,
        G(BitOp, group8),
        I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
        I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),
-       D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
+       D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
        /* 0xC0 - 0xCF */
        D2bv(DstMem | SrcReg | ModRM | Lock),
        N, D(DstMem | SrcReg | ModRM | Mov),
@@ -3602,9 +3603,7 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
 
        switch (d) {
        case OpReg:
-               decode_register_operand(ctxt, op,
-                        op == &ctxt->dst &&
-                        ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
+               decode_register_operand(ctxt, op);
                break;
        case OpImmUByte:
                rc = decode_imm(ctxt, op, 1, false);
@@ -3656,6 +3655,9 @@ static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
        case OpImm:
                rc = decode_imm(ctxt, op, imm_size(ctxt), true);
                break;
+       case OpMem8:
+               ctxt->memop.bytes = 1;
+               goto mem_common;
        case OpMem16:
                ctxt->memop.bytes = 2;
                goto mem_common;