From 5a506b125f1c97c846654ebacc913a136284e42b Mon Sep 17 00:00:00 2001
From: Avi Kivity <avi@redhat.com>
Date: Sun, 1 Aug 2010 15:10:29 +0300
Subject: [PATCH] KVM: x86 emulator: add NoAccess flag for memory instructions
that skip access
Use for INVLPG, which accesses the tlb, not memory.
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 628fb5de6a42..80efe76c1ab8 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -83,6 +83,7 @@
#define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
#define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
/* Misc flags */
+#define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
#define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
#define Undefined (1<<25) /* No Such Instruction */
#define Lock (1<<26) /* lock prefix is allowed for the instruction */
@@ -2067,7 +2068,8 @@ static struct opcode group5[] = {
static struct group_dual group7 = { {
N, N, D(ModRM | SrcMem | Priv), D(ModRM | SrcMem | Priv),
D(SrcNone | ModRM | DstMem | Mov), N,
- D(SrcMem16 | ModRM | Mov | Priv), D(SrcMem | ModRM | ByteOp | Priv),
+ D(SrcMem16 | ModRM | Mov | Priv),
+ D(SrcMem | ModRM | ByteOp | Priv | NoAccess),
}, {
D(SrcNone | ModRM | Priv), N, N, D(SrcNone | ModRM | Priv),
D(SrcNone | ModRM | DstMem | Mov), N,
@@ -2456,7 +2458,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt)
c->src.bytes = (c->d & ByteOp) ? 1 :
c->op_bytes;
/* Don't fetch the address for invlpg: it could be unmapped. */
- if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7)
+ if (c->d & NoAccess)
break;
srcmem_common:
/*