Re: [PATCH v3 0/8] vhost: Reset batched descriptors on SET_VRING_BASE call

Michael S. Tsirkin
2020-03-31T19:53:08Z

On Tue, Mar 31, 2020 at 09:27:56PM +0200, Eugenio Pérez wrote:
> 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.

I pushed vhost branch with patch 1, pls send patches on top of that!

> v3:
> * Rename accesors functions.
> * Make scsi and test use the accesors too.
>
> 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/scsi.c | 14 +-
> drivers/vhost/test.c | 69 ++++++++-
> drivers/vhost/test.h | 1 +
> drivers/vhost/vhost.c | 271 +++++++++++++++++++++++------------
> drivers/vhost/vhost.h | 44 +++++-
> drivers/vhost/vsock.c | 14 +-
> drivers/virtio/virtio_ring.c | 29 ++++
> tools/virtio/linux/virtio.h | 2 +
> tools/virtio/virtio_test.c | 123 ++++++++++++++--
> 10 files changed, 456 insertions(+), 139 deletions(-)
>
> --
> 2.18.1