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.