Re: [Qemu-discuss] qemu 2.8.50 Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed

[Matwey V. Kornilov]

2017-02-03 20:13 GMT+03:00 Bandan Das <address@hidden>:
> "Matwey V. Kornilov" <address@hidden> writes:
> ...
>>>>> I think this means that KVM gave you a list of msrs but
>>>>> when you tried to set them, it could not set all of them and hence, the
>>>>> assert triggers.
>>>>>
>>>>> Are you using a modified kernel ? There could be something useful in the 
>>>>> host
>>>>> dmesg as well.
>>>>>
>>>>
>>>> I use vanilla 4.1.36
>>>>
>>>> Nothing relevant to kvm in dmesg except to
>>>>
>>>> [    5.265836] kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL does not work
>>>> properly. Using workaround
>>>
>>> Can you try using -cpu host,-pmu ? Or do you need vPMU for something ?
>>
>> Hello,
>> -cpu host,-pmu helps. Unfortunately, I need '-cpu host'
>
> You are still using -cpu host. The vcpu will not see the pmu though.
> Can you paste /proc/cpuinfo from the host ?
>

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 44
model name      : Intel(R) Xeon(R) CPU           X5675  @ 3.07GHz
stepping        : 2
microcode       : 0x14
cpu MHz         : 3066.775
cache size      : 12288 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 4
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 11
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush dts mmx fxsr sse sse2 ss ht syscall nx
rdtscp lm constant_tsc arch_perfmon pebs bts nopl xtopology
tsc_reliable nonstop_tsc aperfmperf pni pclmulqdq vmx ssse3 cx16
sse4_1 sse4_2 popcnt aes hypervisor lahf_lm ida arat epb dtherm
tpr_shadow vnmi ept vpid
bogomips        : 6133.55
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

> This does look like a qemu bug.
>
>>>
>>>> [   43.574791] kvm [1249]: vcpu0 unhandled wrmsr: 0x38d data 0
>>>> [   43.580879] kvm [1249]: vcpu0 unhandled wrmsr: 0x38d data 0
>>>> [   43.706797] kvm [1249]: vcpu0 unhandled rdmsr: 0x38d
>>>>
>>>>
>>>>> Bandan
>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> Hello, I've bisected the first bad commit:
>>>>>>
>>>>>>
>>>>>> 48e1a45c3166d659f781171a47dabf4a187ed7a5 is the first bad commit
>>>>>> commit 48e1a45c3166d659f781171a47dabf4a187ed7a5
>>>>>> Author: Paolo Bonzini <address@hidden>
>>>>>> Date:   Wed Mar 30 22:55:29 2016 +0200
>>>>>>
>>>>>>     target-i386: assert that KVM_GET/SET_MSRS can set all requested MSRs
>>>>>>
>>>>>>     This would have caught the bug in the previous patch.
>>>>>>
>>>>>>     Signed-off-by: Paolo Bonzini <address@hidden>
>>>>>>
>>>>>> :040000 040000 5626b58f0d79261bbe8a4fb52bd2cc19c2aa86ad
>>>>>> d7580353932acab9de5c3d024b3f1215eb5659dc M      target-i386



-- 
With best regards,
Matwey V. Kornilov
http://blog.matwey.name
xmpp://address@hidden