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From: Laurent Vivier <lvivier@redhat.com>
Message-ID: <fe15d207-3e01-dd4a-737d-1a3e1acd2f15@redhat.com>
Date: Tue, 11 Apr 2017 16:00:06 +0200
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Subject: Re: [Qemu-devel] [Bug 1681688] Re: qemu live migration failed
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To: Kevin Wolf <kwolf@redhat.com>, 858585 jemmy <jemmy858585@gmail.com>
Cc: Bug 1681688 <1681688@bugs.launchpad.net>, qemu-devel@nongnu.org

On 11/04/2017 15:57, Kevin Wolf wrote:
> Am 11.04.2017 um 15:35 hat 858585 jemmy geschrieben:
>> Hi Kevin:
>>    Can you provide some information about the original bug which you want fix?
>>
>>    the original comment:
>>    Usually guest devices don't like other writers to the same image, so
>>    they use blk_set_perm() to prevent this from happening.
>>
>>    i don't find where the dest qemu will use blk_set_perm during migration.
>>    but after apply this patch, blkconf_apply_backend_options don't update the
>>    blk->root->perm.
> 
> Do I understand correctly that this is not simply live migration, but
> block live migration (with 'migrate -b')?
> 
> Can you please post a backtrace not of the successful case, but of the
> failing assertion?

Kevin,

I've also reproduced this problem without the block live migration while
I was testing my patch to fix the virtio-rng migration.

Laurent