Emulator shouldn't access vcpu directly.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 15 ---------------
arch/x86/kvm/x86.c | 16 +++++++++++++---
2 files changed, 13 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5d786d5..4cc8368 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -941,12 +941,9 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
/* we cannot decode insn before we complete previous rep insn */
WARN_ON(ctxt->restart);
- /* Shadow copy of register state. Committed on successful emulation. */
- memset(c, 0, sizeof(struct decode_cache));
c->eip = ctxt->eip;
c->fetch.start = c->fetch.end = c->eip;
ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS);
- memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
switch (mode) {
case X86EMUL_MODE_REAL:
@@ -2486,16 +2483,13 @@ int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
struct decode_cache *c = &ctxt->decode;
int rc;
- memset(c, 0, sizeof(struct decode_cache));
c->eip = ctxt->eip;
- memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
c->dst.type = OP_NONE;
rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason,
has_error_code, error_code);
if (rc == X86EMUL_CONTINUE) {
- memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
rc = writeback(ctxt, ops);
if (rc == X86EMUL_CONTINUE)
ctxt->eip = c->eip;
@@ -2525,13 +2519,6 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
ctxt->interruptibility = 0;
ctxt->decode.mem_read.pos = 0;
- /* Shadow copy of register state. Committed on successful emulation.
- * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't
- * modify them.
- */
-
- memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
-
if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
goto done;
@@ -3031,8 +3018,6 @@ writeback:
* without decoding
*/
ctxt->decode.mem_read.end = 0;
- /* Commit shadow register state. */
- memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
ctxt->eip = c->eip;
done:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 344d9dd..5fda84e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3782,7 +3782,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
int emulation_type)
{
int r, shadow_mask;
- struct decode_cache *c;
+ struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode;
kvm_clear_exception_queue(vcpu);
vcpu->arch.mmio_fault_cr2 = cr2;
@@ -3807,13 +3807,14 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
? X86EMUL_MODE_VM86 : cs_l
? X86EMUL_MODE_PROT64 : cs_db
? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+ memset(c, 0, sizeof(struct decode_cache));
+ memcpy(c->regs, vcpu->arch.regs, sizeof c->regs);
r = x86_decode_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);
trace_kvm_emulate_insn_start(vcpu);
/* Only allow emulation of specific instructions on #UD
* (namely VMMCALL, sysenter, sysexit, syscall)*/
- c = &vcpu->arch.emulate_ctxt.decode;
if (emulation_type & EMULTYPE_TRAP_UD) {
if (!c->twobyte)
return EMULATE_FAIL;
@@ -3854,6 +3855,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
return EMULATE_DONE;
}
+ /* this is needed for vmware backdor interface to work since it
+ changes registers values during IO operation */
+ memcpy(c->regs, vcpu->arch.regs, sizeof c->regs);
+
restart:
r = x86_emulate_insn(&vcpu->arch.emulate_ctxt, &emulate_ops);
@@ -3874,6 +3879,7 @@ restart:
shadow_mask = vcpu->arch.emulate_ctxt.interruptibility;
kvm_x86_ops->set_interrupt_shadow(vcpu, shadow_mask);
kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
+ memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
if (vcpu->arch.pio.count) {
@@ -4857,6 +4863,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
bool has_error_code, u32 error_code)
{
+ struct decode_cache *c = &vcpu->arch.emulate_ctxt.decode;
int cs_db, cs_l, ret;
cache_all_regs(vcpu);
@@ -4871,6 +4878,8 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
? X86EMUL_MODE_VM86 : cs_l
? X86EMUL_MODE_PROT64 : cs_db
? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
+ memset(c, 0, sizeof(struct decode_cache));
+ memcpy(c->regs, vcpu->arch.regs, sizeof c->regs);
ret = emulator_task_switch(&vcpu->arch.emulate_ctxt, &emulate_ops,
tss_selector, reason, has_error_code,
@@ -4878,7 +4887,8 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason,
if (ret)
return EMULATE_FAIL;
-
+
+ memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
return EMULATE_DONE;
--
1.6.5
--
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