KVM: Improve emulation failure reporting

Report failed opcodes from all locations.

Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index d93ab48..ad08138 100644 (file)
--- 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 e17b433..3b04650 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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();