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Subject: Re: [PATCH 0/6] vhost: Reset batched descriptors on SET_VRING_BASE
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To:     =?UTF-8?Q?Eugenio_P=c3=a9rez?= <eperezma@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>
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        <virtualization@lists.linux-foundation.org>,
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        Stephen Rothwell <sfr@canb.auug.org.au>,
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Date:   Mon, 30 Mar 2020 09:13:57 +0200
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On 29.03.20 13:33, 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.

I guess this could explain my problems that I have seen during reset?

> 
> 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.
> 
> 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.
> 
> 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(-)
>