[Qemu-devel] [PATCH v2 0/6] vhost-user: Specify and implement device IOTLB support

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This series aims at specifying ans implementing the protocol update
required to support device IOTLB with user backends.

In this second non-RFC version, main changes are:
 - spec fixes and clarification
 - rings information update has been restored back to ring enablement time
 - Work around GCC 4.4.7 limitation wrt assignment in unnamed union at
declaration time.

The series can be tested with vhost_iotlb_proto_v2 branch on my gitlab
account[0].

The slave requests channel part is re-used from Marc-André's series submitted
last year[1], with main changes from original version being request/feature
names renaming and addition of the REPLY_ACK feature support.

Regarding IOTLB protocol, one noticeable change is the IOTLB miss request
reply made optionnal (i.e. only if slave requests it by setting the
VHOST_USER_NEED_REPLY flag in the message header). This change provides
more flexibility in the backend implementation of the feature.

The protocol is very close to kernel backends, except that a new
communication channel is introduced to enable the slave to send
requests to the master.

[0]: https://gitlab.com/mcoquelin/dpdk-next-virtio/commits/vhost_iotlb_proto_v2
[1]: https://lists.gnu.org/archive/html/qemu-devel/2016-04/msg00095.html

Marc-André Lureau (2):
  vhost-user: add vhost_user to hold the chr
  vhost-user: add slave-req-fd support

Maxime Coquelin (4):
  vhost: propagate errors in vhost_device_iotlb_miss()
  vhost: rework IOTLB messaging
  vhost: extend ring information update for IOTLB to all rings
  spec/vhost-user spec: Add IOMMU support

 docs/specs/vhost-user.txt         | 118 ++++++++++++++++++++++++-
 hw/virtio/vhost-backend.c         | 130 ++++++++++++++++------------
 hw/virtio/vhost-user.c            | 177 +++++++++++++++++++++++++++++++++++++-
 hw/virtio/vhost.c                 |  27 ++++--
 include/hw/virtio/vhost-backend.h |  23 +++--
 include/hw/virtio/vhost.h         |   2 +-
 6 files changed, 397 insertions(+), 80 deletions(-)

-- 
2.9.4