Test-by: Wang, Yinan <yinan.w...@intel.com>
Best Wishes,
Yinan
> -----Original Message-----
> From: Hu, Jiayu
> Sent: 2019年3月17日 14:39
> To: dev@dpdk.org
> Cc: Bie, Tiwei <tiwei....@intel.com>; maxime.coque...@redhat.com; Wang,
> Yinan <yinan.w...@intel.com>; Hu, Jiayu <jiayu...@intel.com>;
> sta...@dpdk.org
> Subject: [PATCH v2] vhost: fix interrupt suppression for the split ring
>
> The VIRTIO_RING_F_EVENT_IDX feature of split ring might be broken, as the
> value of signalled_used is invalid after live migration, start up and virtio
> driver
> reload.
> This patch fixes it by using signalled_used_valid.
>
> In addition, this patch makes the VIRTIO_RING_F_EVENT_IDX implementation
> of split ring match kernel backend to suppress more interrupts.
>
> Fixes: e37ff954405a ("vhost: support virtqueue interrupt/notification
> suppression")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Jiayu Hu <jiayu...@intel.com>
> ---
> change in v2:
> - fix virtio-net driver reload
>
> lib/librte_vhost/vhost.h | 12 ++++++++----
> lib/librte_vhost/vhost_user.c | 2 ++
> 2 files changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> f008ec4..e9138df 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -633,16 +633,20 @@ vhost_vring_call_split(struct virtio_net *dev, struct
> vhost_virtqueue *vq)
> if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
> uint16_t old = vq->signalled_used;
> uint16_t new = vq->last_used_idx;
> + bool signalled_used_valid = vq->signalled_used_valid;
> +
> + vq->signalled_used = new;
> + vq->signalled_used_valid = true;
>
> VHOST_LOG_DEBUG(VHOST_DATA, "%s: used_event_idx=%d,
> old=%d, new=%d\n",
> __func__,
> vhost_used_event(vq),
> old, new);
> - if (vhost_need_event(vhost_used_event(vq), new, old)
> - && (vq->callfd >= 0)) {
> - vq->signalled_used = vq->last_used_idx;
> +
> + if ((vhost_need_event(vhost_used_event(vq), new, old) &&
> + (vq->callfd >= 0)) ||
> + unlikely(!signalled_used_valid))
> eventfd_write(vq->callfd, (eventfd_t) 1);
> - }
> } else {
> /* Kick the guest if necessary. */
> if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT) diff --git
> a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index
> 36c0c67..01a8d80 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -1298,6 +1298,8 @@ vhost_user_get_vring_base(struct virtio_net
> **pdev,
>
> vq->callfd = VIRTIO_UNINITIALIZED_EVENTFD;
>
> + vq->signalled_used_valid = false;
> +
> if (dev->dequeue_zero_copy)
> free_zmbufs(vq);
> if (vq_is_packed(dev)) {
> --
> 2.7.4
