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KVM: x86: MOVNTI emulation min opsize is not respected

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Commit 3b32004a66 ("KVM: x86: movnti minimum op size of 32-bit is not kept")
did not fully fix the minimum operand size of MONTI emulation. Still, MOVNTI
may be mistakenly performed using 16-bit opsize.

This patch add No16 flag to mark an instruction does not support 16-bits
operand size.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Nadav Amit 2014-11-02 11:55:00 +02:00 committed by Paolo Bonzini
parent 7f187922dd
commit ed9aad215f
1 changed files with 7 additions and 7 deletions
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14
arch/x86/kvm/emulate.c
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@ -167,6 +167,7 @@
#define NoBigReal ((u64)1 << 50) /* No big real mode */
#define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */
#define NearBranch ((u64)1 << 52) /* Near branches */
#define No16 ((u64)1 << 53) /* No 16 bit operand */
#define DstXacc (DstAccLo | SrcAccHi | SrcWrite)
@ -4134,7 +4135,7 @@ static const struct opcode twobyte_table[256] = {
D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
/* 0xC0 - 0xC7 */
F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),
N, D(DstMem | SrcReg | ModRM | Mov),
N, I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov),
N, N, N, GD(0, &group9),
/* 0xC8 - 0xCF */
X8(I(DstReg, em_bswap)),
@ -4571,7 +4572,8 @@ done_prefixes:
return EMULATION_FAILED;
if (unlikely(ctxt->d &
(NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch))) {
(NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch|
No16))) {
/*
* These are copied unconditionally here, and checked unconditionally
* in x86_emulate_insn.
@ -4596,6 +4598,9 @@ done_prefixes:
ctxt->op_bytes = 4;
}
if ((ctxt->d & No16) && ctxt->op_bytes == 2)
ctxt->op_bytes = 4;
if (ctxt->d & Sse)
ctxt->op_bytes = 16;
else if (ctxt->d & Mmx)
@ -5061,11 +5066,6 @@ twobyte_insn:
ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val :
(s16) ctxt->src.val;
break;
case 0xc3: /* movnti */
ctxt->dst.bytes = ctxt->op_bytes;
ctxt->dst.val = (ctxt->op_bytes == 8) ? (u64) ctxt->src.val :
(u32) ctxt->src.val;
break;
default:
goto cannot_emulate;
}