[v2,0/8] vhost: Reset batched descriptors on SET_VRING_BASE call

Message

Eugenio Perez Martin March 31, 2020, 5:59 p.m. UTC

Vhost did not reset properly the batched descriptors on SET_VRING_BASE
event. Because of that, is possible to return an invalid descriptor to
the guest.

This series ammend this, resetting them every time backend changes, and
creates a test to assert correct behavior. To do that, they need to
expose a new function in virtio_ring, virtqueue_reset_free_head, only
on test code.

Another useful thing would be to check if mutex is properly get in
vq private_data accessors. Not sure if mutex debug code allow that,
similar to C++ unique lock::owns_lock. Not acquiring in the function
because caller code holds the mutex in order to perform more actions.

v2:
* Squashed commits.
* Create vq private_data accesors (mst).

This is meant to be applied on top of
c4f1c41a6094582903c75c0dcfacb453c959d457 in
git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git.

Eugenio Pérez (5):
  vhost: Create accessors for virtqueues private_data
  tools/virtio: Add --batch option
  tools/virtio: Add --batch=random option
  tools/virtio: Add --reset=random
  tools/virtio: Make --reset reset ring idx

Michael S. Tsirkin (3):
  vhost: option to fetch descriptors through an independent struct
  vhost: use batched version by default
  vhost: batching fetches

 drivers/vhost/net.c          |  28 ++--
 drivers/vhost/test.c         |  59 +++++++-
 drivers/vhost/test.h         |   1 +
 drivers/vhost/vhost.c        | 271 +++++++++++++++++++++++------------
 drivers/vhost/vhost.h        |  45 +++++-
 drivers/vhost/vsock.c        |  14 +-
 drivers/virtio/virtio_ring.c |  29 ++++
 tools/virtio/linux/virtio.h  |   2 +
 tools/virtio/virtio_test.c   | 123 ++++++++++++++--
 9 files changed, 445 insertions(+), 127 deletions(-)