Re: [Qemu-devel] latest rc: virtio-blk hangs forever after migration

[Andrey Korolyov]

On Thu, Aug 21, 2014 at 8:44 PM, Paolo Bonzini <address@hidden> wrote:
> Il 21/08/2014 18:41, Andrey Korolyov ha scritto:
>> Sorry, the test series revealed that the problem is still here, but
>> with lower hit ratio with modified 2.1-HEAD using selected argument
>> set. The actual root of the issue is in '-cpu
>> qemu64,hv_time,hv_relaxed,hv_vapic,hv_spinlocks=0x1000'
>> Windows-specific addition which can be traded for some idle CPU
>> consumption. Reproduction of bug is quite simple - fire up Windows VM,
>> migrate it two-three times and then try to log in using rdesktop/VNC -
>> if disk is frozen, login progress will freeze too. It is not so easy
>> to detect blocked I/O on Windows in the interactive session due to
>> lack of soft lockup warning equivalent, so one can try such a sequence
>> to check.
>
> What kernel version?
>
> The ioapic patches at http://thread.gmane.org/gmane.linux.kernel/1671045
> fixed exactly a Windows-specific hang in migration.  But it didn't require
> Hyper-V enlightenments.
>
> Paolo

I`m running 3.10, so patches are not here, will try 3.16 soon. Even if
problem will be fixed, it still will be specific for 2.1, earlier
releases working well and I`ll bisect at a time.