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

[Bandan Das]

"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 ?

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