On Sun, Mar 29, 2020 at 01:33:53PM +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, 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. Not sure if this can be avoided. Question: why not reset the batch when private_data changes? At the moment both net and scsi poke at private data directly, if they do this through a wrapper we can use that to 1. check that vq mutex is taken properly 2. reset batching This seems like a slightly better API > > Also, change from https://lkml.org/lkml/2020/3/27/108 is not included, that avoids to update a variable in a loop where it can be updated once. > > This is meant to be applied on top of eccb852f1fe6bede630e2e4f1a121a81e34354ab in git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git, and some commits should be squashed with that series. Thanks a lot! I'll apply this for now so Christian can start testing, but I'd like the comment above addressed before I push this to Linus. > Eugenio Pérez (6): > tools/virtio: Add --batch option > tools/virtio: Add --batch=random option > tools/virtio: Add --reset=random > tools/virtio: Make --reset reset ring idx > vhost: Delete virtqueue batch_descs member > fixup! vhost: batching fetches > > drivers/vhost/test.c | 57 ++++++++++++++++ > drivers/vhost/test.h | 1 + > drivers/vhost/vhost.c | 12 +++- > drivers/vhost/vhost.h | 1 - > drivers/virtio/virtio_ring.c | 18 +++++ > include/linux/virtio.h | 2 + > tools/virtio/linux/virtio.h | 2 + > tools/virtio/virtio_test.c | 123 +++++++++++++++++++++++++++++++---- > 8 files changed, 201 insertions(+), 15 deletions(-) > > -- > 2.18.1
