Re: [Qemu-devel] [PATCH/RFC 2/3] s390x/ais: enable ais when migration is available

[Yi Min Zhao <zyimin@linux.vnet.ibm.com>]

在 2017/9/25 下午7:47, Christian Borntraeger 写道:
> On 09/25/2017 01:45 PM, Cornelia Huck wrote:
>> On Mon, 25 Sep 2017 12:12:49 +0200
>> Christian Borntraeger <borntraeger@de.ibm.com> wrote:
>>
>>> On 09/25/2017 12:07 PM, Cornelia Huck wrote:
>>>> On Fri, 22 Sep 2017 16:27:00 +0200
>>>> Halil Pasic <pasic@linux.vnet.ibm.com> wrote:
>>>>    
>>>>> One thing I would find very helpful is what do we expect to work and not
>>>>> work for which version. Kind of a matrix. For instance should vfio pci
>>>>> work for versions prior 2.11. I think in the not so distant past we
>>>>> changed how SIC works (so it complains when we don't have ais).
>>>> A matrix sounds like a good idea.
>>> I think we do not even need a matrix, a minimum level will suffice because...
>>>> I don't think we really ever had a setup that worked out of the box
>>> exactly: ...it never worked until 2.10 and we do not have libvirt support yet.
>>> Now with the fix 2.10 will also not work, so I think its fair to say
>>>
>>> PCI passthrough via VFIO will be supported for
>>> - KVM: host kernel >= 4.13
>>> - TCG: TBD
>>> - QEMU >= 2.11
>>> - libvirt TBD
>> Make that zpci-per-se, no?
>>
>> with KVM: host kernel >= 4.13 && QEMU >= 2.11
>> with TCG: tbd, I don't think anybody has time to wire this up for 2.11
>>
>> Apropos libvirt: How will it determine whether zpci should be
>> supported? There are some old QEMU + KVM combinations out there that
>> will have a phb (but not be usable by stock Linux guests as the feature
>> bits are missing). Version fence? Check for cpu feature support?
> I think for multibus or something like that Boris wanted to check for a version
> anyway. So maybe 2.11 (now that 2.10 is broken regarding ais) as a minimum QEMU
> level would make sense.
>
>
I think this makes sense. But I think I have to discuss this with Boris.