Re: [PATCH v3 0/7] virtio-mem: Device unplug support

[Mario Casquero <mcasquer@redhat.com>]

This series has been successfully tested by QE. Start a VM, plug a
virtio-mem device, resize the device (adding memory) and verify that
the virtio-mem device cannot be unplugged. Finally, resize the device
(removing all the memory) and check that it can be unplugged
seamlessly.

Tested-by: Mario Casquero <mcasquer@redhat.com>

On Mon, Jul 10, 2023 at 12:07 PM David Hildenbrand <david@redhat.com> wrote:
>
> Any further comments? IMHO this is pretty straight forward. I'll wait
> a bit longer for more feedback.
>
>
> One limitation of virtio-mem is that we cannot currently unplug virtio-mem
> devices that have all memory unplugged from the VM.
>
> Let's properly handle forced unplug (as can be triggered by the VM) and
> add support for ordinary unplug (requests) of virtio-mem devices that are
> in a compatible state (no legacy mode, no plugged memory, no plug request).
>
> Briefly tested on both, x86_64 and aarch64.
>
> v2 -> v3:
> - "virtio-md-pci: New parent type for virtio-mem-pci and virtio-pmem-pci"
>  -> Add MAINTAINERS entry
>
> v1 -> v2:
> - Reduce code duplication and implement it in a cleaner way using a
>   new abstract virtio-md-pci parent class
> - "virtio-md-pci: New parent type for virtio-mem-pci and virtio-pmem-pci"
>  -> Added, use a new aprent type like virtio-input-pci
> - "pc: Factor out (un)plug handling of virtio-md-pci devices"
>  -> Added, factor it cleanly out
> - "arm/virt: Use virtio-md-pci (un)plug functions"
>  -> Added, reduce code duplciation
> - "virtio-md-pci: Handle unplug of virtio based memory devices"
>  -> More generic without any device-specifics
> - "virtio-md-pci: Support unplug requests for compatible devices"
>  -> More generic without any device-specifics
> - "virtio-mem: Prepare for device unplug support"
>  -> Use callback, separated from virtio-mem-pci device change
> - "virtio-mem-pci: Device unplug support"
>  -> Use callback, separated from virtio-mem device change
>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: Eduardo Habkost <eduardo@habkost.net>
> Cc: "Michael S. Tsirkin" <mst@redhat.com>
> Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
> Cc: Igor Mammedov <imammedo@redhat.com>
> Cc: qemu-arm@nongnu.org
> Cc: Gavin Shan <gshan@redhat.com>
> Cc: Mario Casquero <mcasquer@redhat.com>
>
> David Hildenbrand (7):
>   virtio-md-pci: New parent type for virtio-mem-pci and virtio-pmem-pci
>   pc: Factor out (un)plug handling of virtio-md-pci devices
>   arm/virt: Use virtio-md-pci (un)plug functions
>   virtio-md-pci: Handle unplug of virtio based memory devices
>   virtio-md-pci: Support unplug requests for compatible devices
>   virtio-mem: Prepare for device unplug support
>   virtio-mem-pci: Device unplug support
>
>  MAINTAINERS                       |   6 ++
>  hw/arm/virt.c                     |  81 +++-------------
>  hw/i386/pc.c                      |  90 +++---------------
>  hw/virtio/Kconfig                 |   8 +-
>  hw/virtio/meson.build             |   1 +
>  hw/virtio/virtio-md-pci.c         | 151 ++++++++++++++++++++++++++++++
>  hw/virtio/virtio-mem-pci.c        |  54 +++++++++--
>  hw/virtio/virtio-mem-pci.h        |   6 +-
>  hw/virtio/virtio-mem.c            |  25 +++++
>  hw/virtio/virtio-pmem-pci.c       |   5 +-
>  hw/virtio/virtio-pmem-pci.h       |   6 +-
>  include/hw/virtio/virtio-md-pci.h |  44 +++++++++
>  include/hw/virtio/virtio-mem.h    |   1 +
>  13 files changed, 311 insertions(+), 167 deletions(-)
>  create mode 100644 hw/virtio/virtio-md-pci.c
>  create mode 100644 include/hw/virtio/virtio-md-pci.h
>
> --
> 2.41.0
>