From: Jiayu Hu Date: Sun, 17 Mar 2019 06:38:32 +0000 (+0800) Subject: vhost: fix interrupt suppression for the split ring X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=2f706027c8ee1bfcf4895cc35a42f0d2270dc819;p=dpdk.git 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: stable@dpdk.org Signed-off-by: Jiayu Hu Tested-by: Yinan Wang Reviewed-by: Tiwei Bie --- diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index f008ec43bf..e9138dfab4 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 555d09ad9e..4f215769f6 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)) {