[Qemu-devel] [PATCH 0/2] virtio-net: Fix TX data discard on backend disconnection

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

This series fixes TX data discard when backend disconnects.

On backend disconnection, QEMU cannot retrieve its internal
avail index, which makes the virtio queue internal state
inconsistent (last_avail_idx will always be 0, whereas used_idx
is correct).

It results in discarding TX data to corrupt the vring state, by
completing descriptors already completed by the backend.

This series fixes this by restoring last_avail_idx to the vring
used idx, as some backends used to do on reconnection.

Maxime Coquelin (2):
  virtio: Add queue interface to restore avail index from vring used
    index
  vhost: restore avail index from vring used index on disconnection

 hw/virtio/vhost.c          |  4 ++++
 hw/virtio/virtio.c         | 10 ++++++++++
 include/hw/virtio/virtio.h |  1 +
 3 files changed, 15 insertions(+)

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2.14.3