> -----Original Message-----
> From: Maxime Coquelin <maxime.coque...@redhat.com>
> Sent: Wednesday, September 23, 2020 5:49 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo....@intel.com>; ma...@mellanox.com;
> Zawadzki, Tomasz <tomasz.zawad...@intel.com>; Liu, Changpeng
> <changpeng....@intel.com>
> Cc: Maxime Coquelin <maxime.coque...@redhat.com>
> Subject: [PATCH] vhost: fix external backends readiness
>
> Commit d0fcc38f5fa4 ("vhost: improve device readiness notifications")
> makes the assumption that every Virtio devices are considered
> ready for preocessing as soon as first queue pair is configured
> and enabled.
>
> While this is true for Virtio-net, it isn't for Virtio-scsi
> and Virtio-blk.
>
> This patch fixes this by only making this assumption for
> the builtin Virtio-net backend, and restores back to previous
> behaviour for other backends.
>
> Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")
>
> Reported-by: Changpeng Liu <changpeng....@intel.com>
> Signed-off-by: Maxime Coquelin <maxime.coque...@redhat.com>
> Signed-off-by: Changpeng Liu <changpeng....@intel.com>
> ---
> lib/librte_vhost/vhost_user.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index 501218e192..b00e1f91dc 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1343,21 +1343,28 @@ vq_is_ready(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
> vq->enabled;
> }
>
> -#define VIRTIO_DEV_NUM_VQS_TO_BE_READY 2u
> +#define VIRTIO_BUILTIN_NUM_VQS_TO_BE_READY 2u
>
> static int
> virtio_is_ready(struct virtio_net *dev)
> {
> struct vhost_virtqueue *vq;
> - uint32_t i;
> + uint32_t i, nr_vring = dev->nr_vring;
>
> if (dev->flags & VIRTIO_DEV_READY)
> return 1;
>
> - if (dev->nr_vring < VIRTIO_DEV_NUM_VQS_TO_BE_READY)
> + if (!dev->nr_vring)
> return 0;
>
> - for (i = 0; i < VIRTIO_DEV_NUM_VQS_TO_BE_READY; i++) {
> + if (dev->flags & VIRTIO_DEV_BUILTIN_VIRTIO_NET) {
> + nr_vring = VIRTIO_BUILTIN_NUM_VQS_TO_BE_READY;
> +
> + if (dev->nr_vring < nr_vring)
> + return 0;
> + }
> +
> + for (i = 0; i < nr_vring; i++) {
> vq = dev->virtqueue[i];
>
> if (!vq_is_ready(dev, vq))
> --
> 2.26.2
Reviewed-by: Chenbo Xia <chenbo....@intel.com>
