Re: [PATCH v1 00/14] s390x: virtio-mem support

[David Hildenbrand <david@redhat.com>]

On 10.09.24 20:33, Michael S. Tsirkin wrote:
> On Tue, Sep 10, 2024 at 07:57:55PM +0200, David Hildenbrand wrote:
>> This series is based on:
>>      [PATCH v2] virtio: kconfig: memory devices are PCI only [1]
>>
>> I finally found the time (IOW forced myself) to finish virtio-mem
>> support on s390x. The last RFC was from 2020, so I won't talk about
>> what changed -- a lot changed in the meantime :)
>>
>> There is really not much left to do on s390x, because virtio-mem already
>> implements most things we need today (e.g., early-migration,
>> unplugged-inaccessible). The biggest part of this series is just doing what
>> we do with virtio-pci, wiring it up in the machine hotplug handler and ...
>> well, messing with the physical memory layout where we can now exceed
>> initial RAM size and have sparsity (memory holes).
>>
>> I tested a lot of things, including:
>>   * Memory hotplug/unplug
>>   * Device hotplug/unplug
>>   * System resets / reboots
>>   * Migrate to/from file (including storage attributes under KVM)
>>   * Basic live migration
>>   * Basic postcopy live migration
>>
>> More details on how to use it on s390x -- which is pretty much how
>> we use it on other architectures, except
>> s/virtio-mem-pci/virtio-mem-ccw/ --- is in the last patch.
>>
>> This series introduces a new diag(500) "STORAGE LIMIT" subcode that will
>> be documented at [2] once this+kernel part go upstream.
>>
>> There are not many s390x-specific virtio-mem future work items, except:
>> * Storage attribute migration might be improved
>> * We might want to reset storage attributes of unplugged memory
>>    (might or might not be required for upcoming page table reclaim in
>>     Linux; TBD)
> 
> 
> I don't see anything needing virtio specific here, let me know if
> I missed anything.

No, it's really just wiring up virtio-mem.

> A quick look is fine so I guess you can add
> Acked-by: Michael S. Tsirkin <mst@redhat.com>

Thanks!

-- 
Cheers,

David / dhildenb