From ed9aad215ff3374ffd720b83d26fda91e4367090 Mon Sep 17 00:00:00 2001 From: Nadav Amit Date: Sun, 2 Nov 2014 11:55:00 +0200 Subject: [PATCH] KVM: x86: MOVNTI emulation min opsize is not respected Commit 3b32004a66e9 ("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 Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index dab9b74c29de..e020fed0b019 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -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 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 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 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 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 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 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; } -- GitLab