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From: Gleb Natapov <gleb@redhat.com>
To: avi@redhat.com, mtosatti@redhat.com
Cc: kvm@vger.kernel.org
Subject: [PATCH v2 8/8] KVM: Add LOCK prefix validity checking.
Date: Wed, 10 Feb 2010 14:21:36 +0200	[thread overview]
Message-ID: <1265804496-18102-9-git-send-email-gleb@redhat.com> (raw)
In-Reply-To: <1265804496-18102-1-git-send-email-gleb@redhat.com>

Instructions which are not allowed to have LOCK prefix should
generate #UD if one is used.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
 arch/x86/kvm/emulate.c |   85 +++++++++++++++++++++++++++---------------------
 1 files changed, 48 insertions(+), 37 deletions(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 43565b7..9e0d95a 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -76,6 +76,7 @@
 #define GroupDual   (1<<15)     /* Alternate decoding of mod == 3 */
 #define GroupMask   0xff        /* Group number stored in bits 0:7 */
 /* Misc flags */
+#define Lock        (1<<26) /* lock prefix is allowed for the instruction */
 #define Priv        (1<<27) /* instruction generates #GP if current CPL != 0 */
 #define No64	    (1<<28)
 /* Source 2 operand type */
@@ -94,35 +95,35 @@ enum {
 
 static u32 opcode_table[256] = {
 	/* 0x00 - 0x07 */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
 	ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
 	/* 0x08 - 0x0F */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
 	ImplicitOps | Stack | No64, 0,
 	/* 0x10 - 0x17 */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
 	ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
 	/* 0x18 - 0x1F */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
 	ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
 	/* 0x20 - 0x27 */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	DstAcc | SrcImmByte, DstAcc | SrcImm, 0, 0,
 	/* 0x28 - 0x2F */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	0, 0, 0, 0,
 	/* 0x30 - 0x37 */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
 	0, 0, 0, 0,
 	/* 0x38 - 0x3F */
@@ -158,7 +159,7 @@ static u32 opcode_table[256] = {
 	Group | Group1_80, Group | Group1_81,
 	Group | Group1_82, Group | Group1_83,
 	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
 	/* 0x88 - 0x8F */
 	ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov,
 	ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
@@ -263,17 +264,18 @@ static u32 twobyte_table[256] = {
 	DstMem | SrcReg | Src2CL | ModRM, 0, 0,
 	/* 0xA8 - 0xAF */
 	ImplicitOps | Stack, ImplicitOps | Stack,
-	0, DstMem | SrcReg | ModRM | BitOp,
+	0, DstMem | SrcReg | ModRM | BitOp | Lock,
 	DstMem | SrcReg | Src2ImmByte | ModRM,
 	DstMem | SrcReg | Src2CL | ModRM,
 	ModRM, 0,
 	/* 0xB0 - 0xB7 */
-	ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0,
-	    DstMem | SrcReg | ModRM | BitOp,
+	ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
+	0, DstMem | SrcReg | ModRM | BitOp | Lock,
 	0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
 	    DstReg | SrcMem16 | ModRM | Mov,
 	/* 0xB8 - 0xBF */
-	0, 0, Group | Group8, DstMem | SrcReg | ModRM | BitOp,
+	0, 0,
+	Group | Group8, DstMem | SrcReg | ModRM | BitOp | Lock,
 	0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
 	    DstReg | SrcMem16 | ModRM | Mov,
 	/* 0xC0 - 0xCF */
@@ -290,25 +292,37 @@ static u32 twobyte_table[256] = {
 
 static u32 group_table[] = {
 	[Group1_80*8] =
-	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
-	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
-	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
-	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM | Lock,
+	ByteOp | DstMem | SrcImm | ModRM,
 	[Group1_81*8] =
-	DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
-	DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
-	DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
-	DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM | Lock,
+	DstMem | SrcImm | ModRM,
 	[Group1_82*8] =
 	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
 	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
 	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
 	ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
 	[Group1_83*8] =
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM,
 	[Group1A*8] =
 	DstMem | SrcNone | ModRM | Mov | Stack, 0, 0, 0, 0, 0, 0, 0,
 	[Group3_Byte*8] =
@@ -332,10 +346,10 @@ static u32 group_table[] = {
 	SrcMem16 | ModRM | Mov | Priv, SrcMem | ModRM | ByteOp | Priv,
 	[Group8*8] =
 	0, 0, 0, 0,
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
-	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
+	DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM | Lock,
+	DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock,
 	[Group9*8] =
-	0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0,
+	0, ImplicitOps | ModRM | Lock, 0, 0, 0, 0, 0, 0,
 };
 
 static u32 group2_table[] = {
@@ -1580,8 +1594,7 @@ emulate_syscall(struct x86_emulate_ctxt *ctxt)
 	u64 msr_data;
 
 	/* syscall is not available in real mode */
-	if (c->lock_prefix || ctxt->mode == X86EMUL_MODE_REAL
-	    || ctxt->mode == X86EMUL_MODE_VM86)
+	if (ctxt->mode == X86EMUL_MODE_REAL || ctxt->mode == X86EMUL_MODE_VM86)
 		return -1;
 
 	setup_syscalls_segments(ctxt, &cs, &ss);
@@ -1629,10 +1642,6 @@ emulate_sysenter(struct x86_emulate_ctxt *ctxt)
 	struct kvm_segment cs, ss;
 	u64 msr_data;
 
-	/* inject #UD if LOCK prefix is used */
-	if (c->lock_prefix)
-		return -1;
-
 	/* inject #GP if in real mode */
 	if (ctxt->mode == X86EMUL_MODE_REAL) {
 		kvm_inject_gp(ctxt->vcpu, 0);
@@ -1694,10 +1703,6 @@ emulate_sysexit(struct x86_emulate_ctxt *ctxt)
 	u64 msr_data;
 	int usermode;
 
-	/* inject #UD if LOCK prefix is used */
-	if (c->lock_prefix)
-		return -1;
-
 	/* inject #GP if in real mode or Virtual 8086 mode */
 	if (ctxt->mode == X86EMUL_MODE_REAL ||
 	    ctxt->mode == X86EMUL_MODE_VM86) {
@@ -1819,6 +1824,12 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
 	memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
 	saved_eip = c->eip;
 
+	/* LOCK prefix is allowed only with some instructions */
+	if (c->lock_prefix && !(c->d & Lock)) {
+		kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
+		goto done;
+	}
+
 	/* Privileged instruction can be executed only in CPL=0 */
 	if ((c->d & Priv) && kvm_x86_ops->get_cpl(ctxt->vcpu)) {
 		kvm_inject_gp(ctxt->vcpu, 0);
-- 
1.6.5


  parent reply	other threads:[~2010-02-10 12:21 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-10 12:21 [PATCH v2 0/8] Miscellaneous x86 emulator fixes Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 1/8] KVM: Add group8 instruction decoding Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 2/8] KVM: Add group9 " Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 3/8] KVM: Add Virtual-8086 mode of emulation Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 4/8] KVM: fix memory access during x86 emulation Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 5/8] KVM: Check IOPL level during io instruction emulation Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 6/8] KVM: Fix popf emulation Gleb Natapov
2010-02-10 12:21 ` [PATCH v2 7/8] KVM: Check CPL level during privilege instruction emulation Gleb Natapov
2010-02-10 12:21 ` Gleb Natapov [this message]
2010-02-10 12:45 ` [PATCH v2 0/8] Miscellaneous x86 emulator fixes Avi Kivity
2010-03-22 15:48 ` Alexander Graf
2010-03-22 15:51   ` Alexander Graf

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