[libvirt] [PATCH] qemu: Fix backwards compatibility of S390 guests

[Boris Fiuczynski]

On 07/20/2016 09:39 AM, Jiri Denemark wrote:
> On Wed, Jul 20, 2016 at 09:13:54 +0200, Boris Fiuczynski wrote:
>> This patch reverts commit 73e4e10e62e4b1aea64b317be96af5e5488007d7
>> and thereby disabling the panic device autogeneration for S390 guests.
>> In addition tests are patched as well.
>>
>> The reverted commit breaks backwards compatibility of S390 guests.
>> As an example: A domain xml without a panic device can successfully
>> be used to define on two hosts with different libvirt versions.
>> Using this domain xml to define a domain on a host with libivrt v1.3.5
>> makes it impossible to migrate the domain to a host with libvirt v1.3.4
>> or older since libvirt v1.3.5 automatically added a panic device with
>> model s390 which libvirt v1.3.4 or older rejects as unknown model.
>
> In that case, the correct fix is not to revert this patch, but remove
> the pvpanic device from a migratable XML.
>
> Jirka
>
OK, I will send a new patch for that.

-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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