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

[Matwey V. Kornilov]

2017-02-03 0:13 GMT+03:00 Bandan Das <address@hidden>:
> "Matwey V. Kornilov" <address@hidden> writes:
>
>> 02.02.2017 22:36, Matwey V. Kornilov пишет:
>>>
>>> Hello,
>>>
>>> I see the following when try to run qemu from master as the following:
>>>
>>> # ./x86_64-softmmu/qemu-system-x86_64 --version
>>> QEMU emulator version 2.8.50 (v2.8.0-1006-g4e9f524)
>>> Copyright (c) 2003-2016 Fabrice Bellard and the QEMU Project developers
>>> # ./x86_64-softmmu/qemu-system-x86_64 -machine accel=kvm -nodefaults
>>> -no-reboot -nographic -cpu host -vga none  -kernel .build.kernel.kvm
>>> -initrd .build.initrd.kvm -append 'panic=1 no-kvmclock console=ttyS0
>>> loglevel=7' -m 1024 -serial stdio
>>> qemu-system-x86_64: /home/matwey/lab/qemu/target/i386/kvm.c:1849:
>>> kvm_put_msrs: Assertion `ret == cpu->kvm_msr_buf->nmsrs' failed.
>
> 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

[   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