On Thu, Nov 10, 2022 at 1:25 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
>
> On Tue, Nov 08, 2022 at 06:07:45PM +0100, Eugenio Pérez wrote:
> > Control VQ is the way net devices use to send changes to the device state, like
> > the number of active queues or its mac address.
> >
> > QEMU needs to intercept this queue so it can track these changes and is able to
> > migrate the device. It can do it from 1576dbb5bbc4 ("vdpa: Add x-svq to
> > NetdevVhostVDPAOptions"). However, to enable x-svq implies to shadow all VirtIO
> > device's virtqueues, which will damage performance.
> >
> > This series adds address space isolation, so the device and the guest
> > communicate directly with them (passthrough) and CVQ communication is split in
> > two: The guest communicates with QEMU and QEMU forwards the commands to the
> > device.
> >
> > Comments are welcome. Thanks!
>
>
> This is not 7.2 material, right?
>
No it is not.
I should have noted it after PATCH in the subject, sorry.
> > v6:
> > - Do not allocate SVQ resources like file descriptors if SVQ cannot be used.
> > - Disable shadow CVQ if the device does not support it because of net
> > features.
> >
> > v5:
> > - Move vring state in vhost_vdpa_get_vring_group instead of using a
> > parameter.
> > - Rename VHOST_VDPA_NET_CVQ_PASSTHROUGH to VHOST_VDPA_NET_DATA_ASID
> >
> > v4:
> > - Rebased on last CVQ start series, that allocated CVQ cmd bufs at load
> > - Squash vhost_vdpa_cvq_group_is_independent.
> > - Do not check for cvq index on vhost_vdpa_net_prepare, we only have one
> > that callback registered in that NetClientInfo.
> > - Add comment specifying behavior if device does not support _F_ASID
> > - Update headers to a later Linux commit to not to remove SETUP_RNG_SEED
> >
> > v3:
> > - Do not return an error but just print a warning if vdpa device initialization
> > returns failure while getting AS num of VQ groups
> > - Delete extra newline
> >
> > v2:
> > - Much as commented on series [1], handle vhost_net backend through
> > NetClientInfo callbacks instead of directly.
> > - Fix not freeing SVQ properly when device does not support CVQ
> > - Add BIT_ULL missed checking device's backend feature for _F_ASID.
> >
> > Eugenio Pérez (10):
> > vdpa: Use v->shadow_vqs_enabled in vhost_vdpa_svqs_start & stop
> > vhost: set SVQ device call handler at SVQ start
> > vhost: Allocate SVQ device file descriptors at device start
> > vdpa: add vhost_vdpa_net_valid_svq_features
> > vdpa: move SVQ vring features check to net/
> > vdpa: Allocate SVQ unconditionally
> > vdpa: Add asid parameter to vhost_vdpa_dma_map/unmap
> > vdpa: Store x-svq parameter in VhostVDPAState
> > vdpa: Add listener_shadow_vq to vhost_vdpa
> > vdpa: Always start CVQ in SVQ mode
> >
> > include/hw/virtio/vhost-vdpa.h | 10 +-
> > hw/virtio/vhost-shadow-virtqueue.c | 35 +-----
> > hw/virtio/vhost-vdpa.c | 114 ++++++++++---------
> > net/vhost-vdpa.c | 171 ++++++++++++++++++++++++++---
> > hw/virtio/trace-events | 4 +-
> > 5 files changed, 222 insertions(+), 112 deletions(-)
> >
> > --
> > 2.31.1
> >
>
