From 9cd9d5cde7341d5e9de41b1070cea7a98e7d8cc9 Mon Sep 17 00:00:00 2001
From: Sheng Yang <[EMAIL PROTECTED]>
Date: Thu, 15 Nov 2007 15:11:58 +0800
Subject: [PATCH 2/2] KVM: x86 emulator: Discard CR2 in x86 emulator
For CR2 is unreliable and unavailable in many condition, this patch
completely decode memory operand instead of using CR2 in x86 emulator.
Signed-off-by: Sheng Yang <[EMAIL PROTECTED]>
---
drivers/kvm/x86.c | 2 +-
drivers/kvm/x86_emulate.c | 33 +++++++++++++++++++++------------
drivers/kvm/x86_emulate.h | 2 +-
3 files changed, 23 insertions(+), 14 deletions(-)
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index aa6c3d8..85a0776 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -1293,7 +1293,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
vcpu->emulate_ctxt.vcpu = vcpu;
vcpu->emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu);
- vcpu->emulate_ctxt.cr2 = cr2;
+ vcpu->emulate_ctxt.memop = 0;
vcpu->emulate_ctxt.mode =
(vcpu->emulate_ctxt.eflags & X86_EFLAGS_VM)
? X86EMUL_MODE_REAL : cs_l
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index c020010..95536a8 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -880,6 +880,8 @@ done_prefixes:
break;
}
c->src.type = OP_MEM;
+ ctxt->memop = insn_fetch(u32, c->src.bytes, c->eip);
+ c->eip -= c->src.bytes; /* keep the page fault ip */
break;
case SrcImm:
c->src.type = OP_IMM;
@@ -918,14 +920,18 @@ done_prefixes:
c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
break;
case DstMem:
+ c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
/*
* For instructions with a ModR/M byte, switch to register
* access if Mod = 3.
*/
- if ((c->d & ModRM) && c->modrm_mod == 3)
+ if ((c->d & ModRM) && c->modrm_mod == 3) {
c->dst.type = OP_REG;
- else
- c->dst.type = OP_MEM;
+ break;
+ }
+ c->dst.type = OP_MEM;
+ ctxt->memop = insn_fetch(u32, c->dst.bytes, c->eip);
+ c->eip -= c->dst.bytes; /* keep the page fault ip */
break;
}
@@ -1091,13 +1097,13 @@ static inline int emulate_grp45(struct
x86_emulate_ctxt *ctxt,
static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
- unsigned long cr2)
+ unsigned long memop)
{
struct decode_cache *c = &ctxt->decode;
u64 old, new;
int rc;
- rc = ops->read_emulated(cr2, &old, 8, ctxt->vcpu);
+ rc = ops->read_emulated(memop, &old, 8, ctxt->vcpu);
if (rc != 0)
return rc;
@@ -1112,7 +1118,7 @@ static inline int emulate_grp9(struct x86_emulate_ctxt
*ctxt,
new = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
(u32) c->regs[VCPU_REGS_RBX];
- rc = ops->cmpxchg_emulated(cr2, &old, &new, 8, ctxt->vcpu);
+ rc = ops->cmpxchg_emulated(memop, &old, &new, 8, ctxt->vcpu);
if (rc != 0)
return rc;
ctxt->eflags |= EFLG_ZF;
@@ -1175,7 +1181,7 @@ static inline int writeback(struct x86_emulate_ctxt
*ctxt,
int
x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
- unsigned long cr2 = ctxt->cr2;
+ unsigned long memop;
u64 msr_data;
unsigned long saved_eip;
struct decode_cache *c = &ctxt->decode;
@@ -1190,10 +1196,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct
x86_emulate_ops *ops)
saved_eip = c->eip;
if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs))
- cr2 = c->modrm_ea;
+ memop = c->modrm_ea;
+ else if ((c->d & DstMask) != ImplicitOps)
+ memop = ctxt->memop;
+ else memop = 0;
if (c->src.type == OP_MEM) {
- c->src.ptr = (unsigned long *)cr2;
+ c->src.ptr = (unsigned long *)memop;
c->src.val = 0;
rc = ops->read_emulated((unsigned long)c->src.ptr,
&c->src.val,
@@ -1209,7 +1218,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct
x86_emulate_ops *ops)
if (c->dst.type == OP_MEM) {
- c->dst.ptr = (unsigned long *)cr2;
+ c->dst.ptr = (unsigned long *)memop;
c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
c->dst.val = 0;
if (c->d & BitOp) {
@@ -1648,7 +1657,7 @@ twobyte_insn:
&ctxt->eflags);
break;
case 7: /* invlpg*/
- emulate_invlpg(ctxt->vcpu, cr2);
+ emulate_invlpg(ctxt->vcpu, memop);
break;
default:
goto cannot_emulate;
@@ -1819,7 +1828,7 @@ twobyte_special_insn:
break;
}
case 0xc7: /* Grp9 (cmpxchg8b) */
- rc = emulate_grp9(ctxt, ops, cr2);
+ rc = emulate_grp9(ctxt, ops, memop);
if (rc != 0)
goto done;
break;
diff --git a/drivers/kvm/x86_emulate.h b/drivers/kvm/x86_emulate.h
index e34868b..5aacc76 100644
--- a/drivers/kvm/x86_emulate.h
+++ b/drivers/kvm/x86_emulate.h
@@ -149,7 +149,7 @@ struct x86_emulate_ctxt {
/* Linear faulting address (if emulating a page-faulting instruction).
*/
unsigned long eflags;
- unsigned long cr2;
+ unsigned long memop;
/* Emulated execution mode, represented by an X86EMUL_MODE value. */
int mode;
--
1.5.2
From 9cd9d5cde7341d5e9de41b1070cea7a98e7d8cc9 Mon Sep 17 00:00:00 2001
From: Sheng Yang <[EMAIL PROTECTED]>
Date: Thu, 15 Nov 2007 15:11:58 +0800
Subject: [PATCH 2/2] KVM: x86 emulator: Discard CR2 in x86 emulator
For CR2 is unreliable and unavailable in many condition, this patch
completely decode memory operand instead of using CR2 in x86 emulator.
Signed-off-by: Sheng Yang <[EMAIL PROTECTED]>
---
drivers/kvm/x86.c | 2 +-
drivers/kvm/x86_emulate.c | 33 +++++++++++++++++++++------------
drivers/kvm/x86_emulate.h | 2 +-
3 files changed, 23 insertions(+), 14 deletions(-)
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index aa6c3d8..85a0776 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -1293,7 +1293,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
vcpu->emulate_ctxt.vcpu = vcpu;
vcpu->emulate_ctxt.eflags = kvm_x86_ops->get_rflags(vcpu);
- vcpu->emulate_ctxt.cr2 = cr2;
+ vcpu->emulate_ctxt.memop = 0;
vcpu->emulate_ctxt.mode =
(vcpu->emulate_ctxt.eflags & X86_EFLAGS_VM)
? X86EMUL_MODE_REAL : cs_l
diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
index c020010..95536a8 100644
--- a/drivers/kvm/x86_emulate.c
+++ b/drivers/kvm/x86_emulate.c
@@ -880,6 +880,8 @@ done_prefixes:
break;
}
c->src.type = OP_MEM;
+ ctxt->memop = insn_fetch(u32, c->src.bytes, c->eip);
+ c->eip -= c->src.bytes; /* keep the page fault ip */
break;
case SrcImm:
c->src.type = OP_IMM;
@@ -918,14 +920,18 @@ done_prefixes:
c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
break;
case DstMem:
+ c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
/*
* For instructions with a ModR/M byte, switch to register
* access if Mod = 3.
*/
- if ((c->d & ModRM) && c->modrm_mod == 3)
+ if ((c->d & ModRM) && c->modrm_mod == 3) {
c->dst.type = OP_REG;
- else
- c->dst.type = OP_MEM;
+ break;
+ }
+ c->dst.type = OP_MEM;
+ ctxt->memop = insn_fetch(u32, c->dst.bytes, c->eip);
+ c->eip -= c->dst.bytes; /* keep the page fault ip */
break;
}
@@ -1091,13 +1097,13 @@ static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
struct x86_emulate_ops *ops,
- unsigned long cr2)
+ unsigned long memop)
{
struct decode_cache *c = &ctxt->decode;
u64 old, new;
int rc;
- rc = ops->read_emulated(cr2, &old, 8, ctxt->vcpu);
+ rc = ops->read_emulated(memop, &old, 8, ctxt->vcpu);
if (rc != 0)
return rc;
@@ -1112,7 +1118,7 @@ static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
new = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
(u32) c->regs[VCPU_REGS_RBX];
- rc = ops->cmpxchg_emulated(cr2, &old, &new, 8, ctxt->vcpu);
+ rc = ops->cmpxchg_emulated(memop, &old, &new, 8, ctxt->vcpu);
if (rc != 0)
return rc;
ctxt->eflags |= EFLG_ZF;
@@ -1175,7 +1181,7 @@ static inline int writeback(struct x86_emulate_ctxt *ctxt,
int
x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
{
- unsigned long cr2 = ctxt->cr2;
+ unsigned long memop;
u64 msr_data;
unsigned long saved_eip;
struct decode_cache *c = &ctxt->decode;
@@ -1190,10 +1196,13 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
saved_eip = c->eip;
if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs))
- cr2 = c->modrm_ea;
+ memop = c->modrm_ea;
+ else if ((c->d & DstMask) != ImplicitOps)
+ memop = ctxt->memop;
+ else memop = 0;
if (c->src.type == OP_MEM) {
- c->src.ptr = (unsigned long *)cr2;
+ c->src.ptr = (unsigned long *)memop;
c->src.val = 0;
rc = ops->read_emulated((unsigned long)c->src.ptr,
&c->src.val,
@@ -1209,7 +1218,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
if (c->dst.type == OP_MEM) {
- c->dst.ptr = (unsigned long *)cr2;
+ c->dst.ptr = (unsigned long *)memop;
c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
c->dst.val = 0;
if (c->d & BitOp) {
@@ -1648,7 +1657,7 @@ twobyte_insn:
&ctxt->eflags);
break;
case 7: /* invlpg*/
- emulate_invlpg(ctxt->vcpu, cr2);
+ emulate_invlpg(ctxt->vcpu, memop);
break;
default:
goto cannot_emulate;
@@ -1819,7 +1828,7 @@ twobyte_special_insn:
break;
}
case 0xc7: /* Grp9 (cmpxchg8b) */
- rc = emulate_grp9(ctxt, ops, cr2);
+ rc = emulate_grp9(ctxt, ops, memop);
if (rc != 0)
goto done;
break;
diff --git a/drivers/kvm/x86_emulate.h b/drivers/kvm/x86_emulate.h
index e34868b..5aacc76 100644
--- a/drivers/kvm/x86_emulate.h
+++ b/drivers/kvm/x86_emulate.h
@@ -149,7 +149,7 @@ struct x86_emulate_ctxt {
/* Linear faulting address (if emulating a page-faulting instruction). */
unsigned long eflags;
- unsigned long cr2;
+ unsigned long memop;
/* Emulated execution mode, represented by an X86EMUL_MODE value. */
int mode;
--
1.5.2
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