Re: [PATCH V4 00/10] vhost-vDPA multiqueue

[Michael S. Tsirkin]

On Mon, Oct 11, 2021 at 12:28:19PM +0800, Jason Wang wrote:
> Hi All:
> 
> This patch implements the multiqueue support for vhost-vDPA. The most
> important requirement si the control virtqueue support. The virtio-net
> and vhost-net core are tweak to support control virtqueue as if what
> data queue pairs are done: a dedicated vhost_net device which is
> coupled with the NetClientState is intrdouced so most of the existing
> vhost codes could be reused with minor changes. This means the control
> virtqueue will bypass the Qemu. With the control virtqueue, vhost-vDPA
> are extend to support creating and destroying multiqueue queue pairs
> plus the control virtqueue.
> 
> For the future, if we want to support live migration, we can either do
> shadow cvq on top or introduce new interfaces for reporting device
> states.


I had to defer this due to rework I picked up.
I pushed an experimental tree - it still has issues but
if you rebase on top of that I can apply.

> Tests are done via the vp_vdpa driver in L1 guest.
> 
> Changes since V3:
> 
> - fix build with vhost disabled
> 
> Changes since V2:
> 
> - rebase to qemu master
> - use "queue_pairs" instead of "qps"
> - typo fixes
> 
> Changes since V1:
> 
> - start and stop vhost devices when all queues were setup
> - fix the case when driver doesn't support MQ but device support
> - correctly set the batching capability to avoid a map/unmap storm
> - various other tweaks
> 
> Jason Wang (10):
>   vhost-vdpa: open device fd in net_init_vhost_vdpa()
>   vhost-vdpa: classify one time request
>   vhost-vdpa: prepare for the multiqueue support
>   vhost-vdpa: let net_vhost_vdpa_init() returns NetClientState *
>   net: introduce control client
>   vhost-net: control virtqueue support
>   virtio-net: use "queue_pairs" instead of "queues" when possible
>   vhost: record the last virtqueue index for the virtio device
>   virtio-net: vhost control virtqueue support
>   vhost-vdpa: multiqueue support
> 
>  hw/net/vhost_net-stub.c        |   4 +-
>  hw/net/vhost_net.c             |  55 ++++++++---
>  hw/net/virtio-net.c            | 165 ++++++++++++++++++---------------
>  hw/virtio/vhost-vdpa.c         |  56 +++++++++--
>  include/hw/virtio/vhost-vdpa.h |   1 +
>  include/hw/virtio/vhost.h      |   2 +
>  include/hw/virtio/virtio-net.h |   5 +-
>  include/net/net.h              |   5 +
>  include/net/vhost_net.h        |   6 +-
>  net/net.c                      |  24 ++++-
>  net/vhost-vdpa.c               | 127 ++++++++++++++++++++++---
>  11 files changed, 330 insertions(+), 120 deletions(-)
> 
> -- 
> 2.25.1