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path: root/drivers/kvm/x86_emulate.c
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Diffstat (limited to 'drivers/kvm/x86_emulate.c')
-rw-r--r--drivers/kvm/x86_emulate.c98
1 files changed, 52 insertions, 46 deletions
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index be70795b4822..7513cddb929f 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -61,6 +61,7 @@
#define ModRM (1<<6)
/* Destination is only written; never read. */
#define Mov (1<<7)
+#define BitOp (1<<8)
static u8 opcode_table[256] = {
/* 0x00 - 0x07 */
@@ -148,7 +149,7 @@ static u8 opcode_table[256] = {
0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM
};
-static u8 twobyte_table[256] = {
+static u16 twobyte_table[256] = {
/* 0x00 - 0x0F */
0, SrcMem | ModRM | DstReg, 0, 0, 0, 0, ImplicitOps, 0,
0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0,
@@ -180,16 +181,16 @@ static u8 twobyte_table[256] = {
/* 0x90 - 0x9F */
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 0xA0 - 0xA7 */
- 0, 0, 0, DstMem | SrcReg | ModRM, 0, 0, 0, 0,
+ 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0,
/* 0xA8 - 0xAF */
- 0, 0, 0, DstMem | SrcReg | ModRM, 0, 0, 0, 0,
+ 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0,
/* 0xB0 - 0xB7 */
ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0,
- DstMem | SrcReg | ModRM,
+ DstMem | SrcReg | ModRM | BitOp,
0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
DstReg | SrcMem16 | ModRM | Mov,
/* 0xB8 - 0xBF */
- 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM,
+ 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM | BitOp,
0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
DstReg | SrcMem16 | ModRM | Mov,
/* 0xC0 - 0xCF */
@@ -469,7 +470,8 @@ static int read_descriptor(struct x86_emulate_ctxt *ctxt,
int
x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
- u8 b, d, sib, twobyte = 0, rex_prefix = 0;
+ unsigned d;
+ u8 b, sib, twobyte = 0, rex_prefix = 0;
u8 modrm, modrm_mod = 0, modrm_reg = 0, modrm_rm = 0;
unsigned long *override_base = NULL;
unsigned int op_bytes, ad_bytes, lock_prefix = 0, rep_prefix = 0, i;
@@ -726,46 +728,6 @@ done_prefixes:
;
}
- /* Decode and fetch the destination operand: register or memory. */
- switch (d & DstMask) {
- case ImplicitOps:
- /* Special instructions do their own operand decoding. */
- goto special_insn;
- case DstReg:
- dst.type = OP_REG;
- if ((d & ByteOp)
- && !(twobyte_table && (b == 0xb6 || b == 0xb7))) {
- dst.ptr = decode_register(modrm_reg, _regs,
- (rex_prefix == 0));
- dst.val = *(u8 *) dst.ptr;
- dst.bytes = 1;
- } else {
- dst.ptr = decode_register(modrm_reg, _regs, 0);
- switch ((dst.bytes = op_bytes)) {
- case 2:
- dst.val = *(u16 *)dst.ptr;
- break;
- case 4:
- dst.val = *(u32 *)dst.ptr;
- break;
- case 8:
- dst.val = *(u64 *)dst.ptr;
- break;
- }
- }
- break;
- case DstMem:
- dst.type = OP_MEM;
- dst.ptr = (unsigned long *)cr2;
- dst.bytes = (d & ByteOp) ? 1 : op_bytes;
- if (!(d & Mov) && /* optimisation - avoid slow emulated read */
- ((rc = ops->read_emulated((unsigned long)dst.ptr,
- &dst.val, dst.bytes, ctxt)) != 0))
- goto done;
- break;
- }
- dst.orig_val = dst.val;
-
/*
* Decode and fetch the source operand: register, memory
* or immediate.
@@ -838,6 +800,50 @@ done_prefixes:
break;
}
+ /* Decode and fetch the destination operand: register or memory. */
+ switch (d & DstMask) {
+ case ImplicitOps:
+ /* Special instructions do their own operand decoding. */
+ goto special_insn;
+ case DstReg:
+ dst.type = OP_REG;
+ if ((d & ByteOp)
+ && !(twobyte_table && (b == 0xb6 || b == 0xb7))) {
+ dst.ptr = decode_register(modrm_reg, _regs,
+ (rex_prefix == 0));
+ dst.val = *(u8 *) dst.ptr;
+ dst.bytes = 1;
+ } else {
+ dst.ptr = decode_register(modrm_reg, _regs, 0);
+ switch ((dst.bytes = op_bytes)) {
+ case 2:
+ dst.val = *(u16 *)dst.ptr;
+ break;
+ case 4:
+ dst.val = *(u32 *)dst.ptr;
+ break;
+ case 8:
+ dst.val = *(u64 *)dst.ptr;
+ break;
+ }
+ }
+ break;
+ case DstMem:
+ dst.type = OP_MEM;
+ dst.ptr = (unsigned long *)cr2;
+ dst.bytes = (d & ByteOp) ? 1 : op_bytes;
+ if (d & BitOp) {
+ dst.ptr += src.val / BITS_PER_LONG;
+ dst.bytes = sizeof(long);
+ }
+ if (!(d & Mov) && /* optimisation - avoid slow emulated read */
+ ((rc = ops->read_emulated((unsigned long)dst.ptr,
+ &dst.val, dst.bytes, ctxt)) != 0))
+ goto done;
+ break;
+ }
+ dst.orig_val = dst.val;
+
if (twobyte)
goto twobyte_insn;