[PATCH v2 0/7] virtio: enable VIRTIO_F_RING_PACKED for all devices

[Stefan Hajnoczi <stefanha@redhat.com>]

v2:
 * Add libvhost-user VHOST_USER_GET_FEATURES patch to start reporting feature
   bits correctly (already reviewed by Marc-André Lureau)
 * Rephrase doc comments and drop vhost_get_default_features() [Jason]
 * Simplify hw/core/machine.c compat props by setting packed=off on the
   virtio-dev base class [Jason]

The VIRTIO 1.1 packed virtqueue layout improves performance and guest driver
support has been available since Linux v5.0. virtio-blk benchmarks show it is
beneficial for non-net devices too so I wrote patches to enable it for all
devices.

It turned out to be trickier than I expected because vhost feature negotiation
is currently not ready for new virtqueue feature bits like
VIRTIO_F_RING_PACKED.

Patch 1 fixes libqos. Patch 2 fixes libvhost-user. Patch 3 adds clarifications
to the vhost-user specification. Patches 4-6 solve the vhost feature issues in
QEMU. Finally, Patch 6 enables packed virtqueues.

Stefan Hajnoczi (7):
  tests/libqos: mask out VIRTIO_F_RING_PACKED for now
  libvhost-user: advertise vring features
  docs: document non-net VHOST_USER_GET_FEATURES behavior
  vhost: involve device backends in feature negotiation
  vhost-user-blk: add VIRTIO_F_RING_PACKED feature bit
  vhost-scsi: add VIRTIO_F_VERSION_1 and VIRTIO_F_RING_PACKED
  virtio: enable VIRTIO_F_RING_PACKED for all devices

 include/hw/virtio/vhost.h               |  1 +
 include/hw/virtio/virtio-gpu.h          |  2 ++
 include/hw/virtio/virtio.h              |  2 +-
 include/sysemu/cryptodev-vhost.h        | 11 +++++++++++
 backends/cryptodev-vhost.c              | 21 +++++++++++++++++++++
 contrib/libvhost-user/libvhost-user.c   | 10 ++++++++++
 contrib/vhost-user-blk/vhost-user-blk.c |  4 +---
 hw/block/vhost-user-blk.c               |  1 +
 hw/core/machine.c                       |  4 +++-
 hw/display/vhost-user-gpu.c             | 18 ++++++++++++++++++
 hw/display/virtio-gpu-base.c            |  2 +-
 hw/input/vhost-user-input.c             | 11 +++++++++++
 hw/scsi/vhost-scsi.c                    |  2 ++
 hw/scsi/vhost-user-scsi.c               |  2 ++
 hw/virtio/vhost-user-fs.c               |  6 ++++--
 hw/virtio/vhost-vsock.c                 |  7 +++++--
 hw/virtio/vhost.c                       | 24 ++++++++++++++++++++++++
 hw/virtio/virtio-crypto.c               |  3 ++-
 tests/qtest/libqos/virtio.c             |  3 ++-
 docs/interop/vhost-user.rst             | 21 +++++++++++++++++++++
 20 files changed, 143 insertions(+), 12 deletions(-)

-- 
2.26.2