Re: [PATCH v3 00/19] vdpa net devices Rx filter change notification with Shadow VQ

[Michael S. Tsirkin]

On Mon, Jul 18, 2022 at 11:32:57AM +0800, Jason Wang wrote:
> On Sat, Jul 16, 2022 at 1:18 AM Eugenio Pérez <eperezma@redhat.com> wrote:
> >
> > Control virtqueue is used by networking device for accepting various
> > commands from the driver. It's a must to support advanced configurations.
> >
> > Rx filtering event is issues by qemu when device's MAC address changed once 
> > and
> > the previous one has not been queried by external agents.
> >
> > Shadow VirtQueue (SVQ) already makes possible tracking the state of 
> > virtqueues,
> > effectively intercepting them so qemu can track what regions of memory are
> > dirty because device action and needs migration. However, this does not 
> > solve
> > networking device state seen by the driver because CVQ messages, like 
> > changes
> > on MAC addresses from the driver.
> >
> > This series uses SVQ infrastructure to intercept networking control messages
> > used by the device. This way, qemu is able to update VirtIONet device model 
> > and
> > react to them. In particular, this series enables rx filter change
> > notification.
> >
> > This is a prerequisite to achieve net vdpa device with CVQ live migration.
> > It's a stripped down version of [1], with error paths checked and no 
> > migration
> > enabled.
> >
> > First nine patches reorder and clean code base so its easier to apply later
> > ones. No functional change should be noticed from these changes.
> >
> > Patches from 11 to 14 enable SVQ API to make other parts of qemu to interact
> > with it. In particular, they will be used by vhost-vdpa net to handle CVQ
> > messages.
> >
> > Patches 15 to 17 enable the update of the virtio-net device model for each
> > CVQ message acknowledged by the device.
> >
> > Last patches enable x-svq parameter, forbidding device migration since it is
> > not restored in the destination's vdpa device yet. This will be added in 
> > later
> > series, using this work.
> >
> > Comments are welcome.
> > v3:
> > - Replace SVQElement with SVQDescState
> >
> > v2:
> > - (Comments from series [1]).
> > - Active poll for CVQ answer instead of relay on async used callback
> > - Do not offer a new buffer to device but reuse qemu's
> > - Use vhost_svq_add instead of not needed vhost_svq_inject
> > - Delete used and detach callbacks, not needed anymore
> > - Embed members of SVQElement in VirtQueueElement
> > - Reuse the same buffers for all CVQ commands
> >
> > [1] 
> > 20220706184008.1649478-1-eperezma@redhat.com/">https://patchwork.kernel.org/project/qemu-devel/cover/20220706184008.1649478-1-eperezma@redhat.com/
> >
> > Eugenio Pérez (19):
> >   vhost: move descriptor translation to vhost_svq_vring_write_descs
> >   virtio-net: Expose MAC_TABLE_ENTRIES
> >   virtio-net: Expose ctrl virtqueue logic
> >   vhost: Reorder vhost_svq_kick
> >   vhost: Move vhost_svq_kick call to vhost_svq_add
> >   vhost: Check for queue full at vhost_svq_add
> >   vhost: Decouple vhost_svq_add from VirtQueueElement
> >   vhost: Add SVQDescState
> >   vhost: Track number of descs in SVQDescState
> >   vhost: add vhost_svq_push_elem
> >   vhost: Expose vhost_svq_add
> >   vhost: add vhost_svq_poll
> >   vhost: Add svq avail_handler callback
> >   vdpa: Export vhost_vdpa_dma_map and unmap calls
> >   vdpa: manual forward CVQ buffers
> >   vdpa: Buffer CVQ support on shadow virtqueue
> >   vdpa: Extract get features part from vhost_vdpa_get_max_queue_pairs
> >   vdpa: Add device migration blocker
> >   vdpa: Add x-svq to NetdevVhostVDPAOptions
> >
> >  qapi/net.json                      |   9 +-
> >  hw/virtio/vhost-shadow-virtqueue.h |  52 ++++-
> >  include/hw/virtio/vhost-vdpa.h     |   8 +
> >  include/hw/virtio/virtio-net.h     |   7 +
> >  hw/net/virtio-net.c                |  85 ++++---
> >  hw/virtio/vhost-shadow-virtqueue.c | 202 +++++++++++-----
> >  hw/virtio/vhost-vdpa.c             |  25 +-
> >  net/vhost-vdpa.c                   | 357 +++++++++++++++++++++++++++--
> >  8 files changed, 627 insertions(+), 118 deletions(-)
> 
> Looks good to me.
> 
> Michael, if you don't object, I plan to merge this series so vendors
> can start to test this.
> 
> Thanks

Sounds good.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> >
> > --
> > 2.31.1
> >
> >