[RFC PATCH v4 00/20] Net Control VQ support with asid in vDPA SVQ

[Eugenio Pérez]

Control virtqueue is used by networking device for accepting various
commands from the driver. It's a must to support multiqueue and other
configurations.

Shadow VirtQueue (SVQ) already makes possible migration of virtqueue
states, 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.

To solve that, this series uses SVQ infraestructure proposed at SVQ to
intercept networking control messages used by the device. This way, qemu is
able to update VirtIONet device model and to migrate it.

You can run qemu in two modes after applying this series: only intercepting
cvq with x-cvq-svq=on or intercept all the virtqueues adding cmdline x-svq=on:

-netdev 
type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-0,id=vhost-vdpa0,x-cvq-svq=on,x-svq=on

The most updated kernel part of ASID is proposed at [1].

Other modes without x-cvq-svq have been not tested with this series. Other vq
cmd commands than set mac are not tested. Some details like error control are
not 100% tested neither.

The firsts patches will be proposed sepratedly.

Comments are welcomed on every aspect of the patch.

Changes from rfc v3:
* Fix bad returning of descriptors to SVQ list.

Changes from rfc v2:
* Fix use-after-free.

Changes from rfc v1:
* Rebase to latest master.
* Configure ASID instead of assuming cvq asid != data vqs asid.
* Update device model so (MAC) state can be migrated too.

[1] https://lkml.kernel.org/kvm/20220224212314.1326-1-gdawar@xilinx.com/

Eugenio Pérez (20):
  vhost: Fix bad return of descriptors
  util: Return void on iova_tree_remove
  vdpa: Add x-svq to NetdevVhostVDPAOptions
  vhost: move descriptor translation to vhost_svq_vring_write_descs
  vdpa: Fix index calculus at vhost_vdpa_svqs_start
  virtio-net: use g_memdup2() instead of unsafe g_memdup()
  virtio-net: Expose ctrl virtqueue logic
  vdpa: Extract get geatures part from vhost_vdpa_get_max_queue_pairs
  virtio: Make virtqueue_alloc_element non-static
  vhost: Add SVQElement
  vhost: Add custom used buffer callback
  vdpa: control virtqueue support on shadow virtqueue
  vhost: Add vhost_iova_tree_find
  vdpa: Add map/unmap operation callback to SVQ
  vhost: Add vhost_svq_inject
  vdpa: add NetClientState->start() callback
  vdpa: Add vhost_vdpa_start_control_svq
  vhost: Update kernel headers
  vdpa: Add asid attribute to vdpa device
  vdpa: Add x-cvq-svq

 qapi/net.json                                |  13 +-
 hw/virtio/vhost-iova-tree.h                  |   2 +
 hw/virtio/vhost-shadow-virtqueue.h           |  46 ++-
 include/hw/virtio/vhost-vdpa.h               |   5 +
 include/hw/virtio/virtio-net.h               |   3 +
 include/hw/virtio/virtio.h                   |   1 +
 include/net/net.h                            |   2 +
 include/qemu/iova-tree.h                     |   4 +-
 include/standard-headers/linux/vhost_types.h |  11 +-
 linux-headers/linux/vhost.h                  |  25 +-
 hw/net/vhost_net.c                           |   4 +
 hw/net/virtio-net.c                          |  82 +++--
 hw/virtio/vhost-iova-tree.c                  |  14 +
 hw/virtio/vhost-shadow-virtqueue.c           | 255 ++++++++++---
 hw/virtio/vhost-vdpa.c                       |  70 +++-
 hw/virtio/virtio.c                           |   2 +-
 net/vhost-vdpa.c                             | 368 +++++++++++++++++--
 util/iova-tree.c                             |   4 +-
 18 files changed, 779 insertions(+), 132 deletions(-)

-- 
2.27.0