Re: [PATCH v2 00/14] s390x: virtio-mem support

[David Hildenbrand]

On 08.10.24 12:54, David Hildenbrand wrote:
> Based on current master.
>
> 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 in the kernel and 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)
>
> The Linux driver is available at [3].
>
> [1] https://lkml.kernel.org/r/20240906101658.514470-1-pbonzini@redhat.com
> [2] https://gitlab.com/davidhildenbrand/s390x-os-virt-spec
> [3] https://lkml.kernel.org/r/20240910191541.2179655-6-david@redhat.com

Gentle ping (and thanks to Thomas for the review!).

I assume the kernel portion will go upstream in the next merge window. 
I'd like get the QEMU parts merged soon after that.

9.2 is going to get released in roughly one month, so there is still time.

@Thomas, this is mostly s390x stuff, so I guess it should go through the 
s390x tree? But I could also take this through my "memory devices" tree.

--
Cheers,

David / dhildenb