Such messages in the system log very often cause confusion because users
understand the "kvm: unhandled MSR" messages as errors.
Switch to trace points, making the information available on demand.
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index fe5e00e..c461368 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -318,6 +318,40 @@ TRACE_EVENT(kvm_msr,
#define trace_kvm_msr_write_ex(ecx, data) trace_kvm_msr(1, ecx, data, true)
/*
+ * Tracepoint for unhandled guest MSR access.
+ */
+TRACE_EVENT(kvm_msr_unhandled,
+ TP_PROTO(bool write, u32 ecx, u64 data, bool unhandled),
+ TP_ARGS(write, ecx, data, unhandled),
+
+ TP_STRUCT__entry(
+ __field( u32, ecx )
+ __field( u64, data )
+ __field( bool, write )
+ __field( bool, unhandled )
+ ),
+
+ TP_fast_assign(
+ __entry->ecx = ecx;
+ __entry->data = data;
+ __entry->write = write;
+ __entry->unhandled = unhandled;
+ ),
+
+ TP_printk("unhandled MSR %s %x = 0x%llx (%s)",
+ __entry->write ? "write" : "read",
+ __entry->ecx, __entry->data,
+ __entry->unhandled ? "injected #GP" : "ignored")
+);
+
+#define trace_kvm_msr_unhandled_read(ecx) trace_kvm_msr(0, ecx, 0, false)
+#define trace_kvm_msr_unhandled_read_ex(ecx) trace_kvm_msr(0, ecx, 0, true)
+#define trace_kvm_msr_unhandled_write(ecx, data) \
+ trace_kvm_msr(1, ecx, data, false)
+#define trace_kvm_msr_unhandled_write_ex(ecx, data) \
+ trace_kvm_msr(1, ecx, data, true)
+
+/*
* Tracepoint for guest CR access.
*/
TRACE_EVENT(kvm_cr,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c243b81..f5abcce 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1772,8 +1772,7 @@ static int set_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32
msr, u64 data)
break;
}
default:
- vcpu_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
- "data 0x%llx\n", msr, data);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
}
return 0;
@@ -1805,8 +1804,7 @@ static int set_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr,
u64 data)
case HV_X64_MSR_TPR:
return kvm_hv_vapic_msr_write(vcpu, APIC_TASKPRI, data);
default:
- vcpu_unimpl(vcpu, "HYPER-V unimplemented wrmsr: 0x%x "
- "data 0x%llx\n", msr, data);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
}
@@ -1888,15 +1886,13 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
data &= ~(u64)0x100; /* ignore ignne emulation enable */
data &= ~(u64)0x8; /* ignore TLB cache disable */
if (data != 0) {
- vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
- data);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
}
break;
case MSR_FAM10H_MMIO_CONF_BASE:
if (data != 0) {
- vcpu_unimpl(vcpu, "unimplemented MMIO_CONF_BASE wrmsr: "
- "0x%llx\n", data);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
}
break;
@@ -1911,8 +1907,8 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
thus reserved and should throw a #GP */
return 1;
}
- vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
- __func__, data);
+
+ trace_kvm_msr_unhandled_write(msr, data);
break;
case MSR_IA32_UCODE_REV:
case MSR_IA32_UCODE_WRITE:
@@ -2020,8 +2016,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
case MSR_K7_EVNTSEL2:
case MSR_K7_EVNTSEL3:
if (data != 0)
- vcpu_unimpl(vcpu, "unimplemented perfctr wrmsr: "
- "0x%x data 0x%llx\n", msr, data);
+ trace_kvm_msr_unhandled_write(msr, data);
break;
/* at least RHEL 4 unconditionally writes to the perfctr registers,
* so we ignore writes to make it happy.
@@ -2030,8 +2025,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
case MSR_K7_PERFCTR1:
case MSR_K7_PERFCTR2:
case MSR_K7_PERFCTR3:
- vcpu_unimpl(vcpu, "unimplemented perfctr wrmsr: "
- "0x%x data 0x%llx\n", msr, data);
+ trace_kvm_msr_unhandled_write(msr, data);
break;
case MSR_P6_PERFCTR0:
case MSR_P6_PERFCTR1:
@@ -2042,8 +2036,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
return kvm_pmu_set_msr(vcpu, msr, data);
if (pr || data != 0)
- vcpu_unimpl(vcpu, "disabled perfctr wrmsr: "
- "0x%x data 0x%llx\n", msr, data);
+ trace_kvm_msr_unhandled_write(msr, data);
break;
case MSR_K7_CLK_CTL:
/*
@@ -2069,7 +2062,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
/* Drop writes to this legacy MSR -- see rdmsr
* counterpart for further detail.
*/
- vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n", msr, data);
+ trace_kvm_msr_unhandled_write(msr, data);
break;
case MSR_AMD64_OSVW_ID_LENGTH:
if (!guest_cpuid_has_osvw(vcpu))
@@ -2087,12 +2080,10 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct
msr_data *msr_info)
if (kvm_pmu_msr(vcpu, msr))
return kvm_pmu_set_msr(vcpu, msr, data);
if (!ignore_msrs) {
- vcpu_unimpl(vcpu, "unhandled wrmsr: 0x%x data %llx\n",
- msr, data);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
} else {
- vcpu_unimpl(vcpu, "ignored wrmsr: 0x%x data %llx\n",
- msr, data);
+ trace_kvm_msr_unhandled_write(msr, data);
break;
}
}
@@ -2195,7 +2186,7 @@ static int get_msr_hyperv_pw(struct kvm_vcpu *vcpu, u32
msr, u64 *pdata)
data = kvm->arch.hv_hypercall;
break;
default:
- vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
+ trace_kvm_msr_unhandled_write_ex(msr, data);
return 1;
}
@@ -2226,7 +2217,7 @@ static int get_msr_hyperv(struct kvm_vcpu *vcpu, u32 msr,
u64 *pdata)
data = vcpu->arch.hv_vapic;
break;
default:
- vcpu_unimpl(vcpu, "Hyper-V unhandled rdmsr: 0x%x\n", msr);
+ trace_kvm_msr_unhandled_read_ex(msr);
return 1;
}
*pdata = data;
@@ -2385,10 +2376,10 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr,
u64 *pdata)
if (kvm_pmu_msr(vcpu, msr))
return kvm_pmu_get_msr(vcpu, msr, pdata);
if (!ignore_msrs) {
- vcpu_unimpl(vcpu, "unhandled rdmsr: 0x%x\n", msr);
+ trace_kvm_msr_unhandled_read_ex(msr);
return 1;
} else {
- vcpu_unimpl(vcpu, "ignored rdmsr: 0x%x\n", msr);
+ trace_kvm_msr_unhandled_read(msr);
data = 0;
}
break;
--
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