[PATCH 096/104] KVM: Improve emulation failure reporting

Avi Kivity
2007-09-17T08:32:18Z

Report failed opcodes from all locations.

Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm.h | 1 +
drivers/kvm/kvm_main.c | 16 ++++++++--------
drivers/kvm/svm.c | 2 +-
drivers/kvm/vmx.c | 2 +-
4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index d93ab48..ad08138 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -558,6 +558,7 @@ enum emulation_result {

int emulate_instruction(struct kvm_vcpu *vcpu, struct kvm_run *run,
unsigned long cr2, u16 error_code);
+void kvm_report_emulation_failure(struct kvm_vcpu *cvpu, const char *context);
void realmode_lgdt(struct kvm_vcpu *vcpu, u16 size, unsigned long address);
void realmode_lidt(struct kvm_vcpu *vcpu, u16 size, unsigned long address);
void realmode_lmsw(struct kvm_vcpu *vcpu, unsigned long msw,
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index e6301ce..99e4917 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1240,25 +1240,25 @@ int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr, unsigned long value)
return X86EMUL_CONTINUE;
}

-static void report_emulation_failure(struct x86_emulate_ctxt *ctxt)
+void kvm_report_emulation_failure(struct kvm_vcpu *vcpu, const char *context)
{
static int reported;
u8 opcodes[4];
- unsigned long rip = ctxt->vcpu->rip;
+ unsigned long rip = vcpu->rip;
unsigned long rip_linear;

- rip_linear = rip + get_segment_base(ctxt->vcpu, VCPU_SREG_CS);
+ rip_linear = rip + get_segment_base(vcpu, VCPU_SREG_CS);

if (reported)
return;

- emulator_read_std(rip_linear, (void *)opcodes, 4, ctxt->vcpu);
+ emulator_read_std(rip_linear, (void *)opcodes, 4, vcpu);

- printk(KERN_ERR "emulation failed but !mmio_needed?"
- " rip %lx %02x %02x %02x %02x\n",
- rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
+ printk(KERN_ERR "emulation failed (%s) rip %lx %02x %02x %02x %02x\n",
+ context, rip, opcodes[0], opcodes[1], opcodes[2], opcodes[3]);
reported = 1;
}
+EXPORT_SYMBOL_GPL(kvm_report_emulation_failure);

struct x86_emulate_ops emulate_ops = {
.read_std = emulator_read_std,
@@ -1323,7 +1323,7 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
if (kvm_mmu_unprotect_page_virt(vcpu, cr2))
return EMULATE_DONE;
if (!vcpu->mmio_needed) {
- report_emulation_failure(&emulate_ctxt);
+ kvm_report_emulation_failure(vcpu, "mmio");
return EMULATE_FAIL;
}
return EMULATE_DO_MMIO;
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 95681ea..729f1cd 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -960,7 +960,7 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
++svm->vcpu.stat.mmio_exits;
return 0;
case EMULATE_FAIL:
- vcpu_printf(&svm->vcpu, "%s: emulate fail\n", __FUNCTION__);
+ kvm_report_emulation_failure(&svm->vcpu, "pagetable");
break;
default:
BUG();
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index c44c9ac..4f115a8 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1798,7 +1798,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
++vcpu->stat.mmio_exits;
return 0;
case EMULATE_FAIL:
- vcpu_printf(vcpu, "%s: emulate fail\n", __FUNCTION__);
+ kvm_report_emulation_failure(vcpu, "pagetable");
break;
default:
BUG();