[dpdk-dev] [PATCH v2 1/2] vhost: add vhost_vring_call() helper

[Stefan Hajnoczi <stefanha@redhat.com>]

Extract the callfd eventfd signal operation so virtio_net.c does not
have to repeat it multiple times.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 lib/librte_vhost/vhost.h      | 12 ++++++++++++
 lib/librte_vhost/virtio_net.c | 23 +++--------------------
 2 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 04f54cb60..ac81d83bb 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -394,4 +394,16 @@ vhost_iova_to_vva(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	return __vhost_iova_to_vva(dev, vq, iova, size, perm);
 }
 
+static __rte_always_inline void
+vhost_vring_call(struct vhost_virtqueue *vq)
+{
+	/* Flush used->idx update before we read avail->flags. */
+	rte_mb();
+
+	/* Kick the guest if necessary. */
+	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
+			&& (vq->callfd >= 0))
+		eventfd_write(vq->callfd, (eventfd_t)1);
+}
+
 #endif /* _VHOST_NET_CDEV_H_ */
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 79d80f7fd..a92a5181d 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -408,13 +408,7 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id,
 		offsetof(struct vring_used, idx),
 		sizeof(vq->used->idx));
 
-	/* flush used->idx update before we read avail->flags. */
-	rte_mb();
-
-	/* Kick the guest if necessary. */
-	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
-			&& (vq->callfd >= 0))
-		eventfd_write(vq->callfd, (eventfd_t)1);
+	vhost_vring_call(vq);
 out:
 	if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
 		vhost_user_iotlb_rd_unlock(vq);
@@ -701,14 +695,7 @@ virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
 
 	if (likely(vq->shadow_used_idx)) {
 		flush_shadow_used_ring(dev, vq);
-
-		/* flush used->idx update before we read avail->flags. */
-		rte_mb();
-
-		/* Kick the guest if necessary. */
-		if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
-				&& (vq->callfd >= 0))
-			eventfd_write(vq->callfd, (eventfd_t)1);
+		vhost_vring_call(vq);
 	}
 
 out:
@@ -1107,11 +1094,7 @@ update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq,
 	vq->used->idx += count;
 	vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx),
 			sizeof(vq->used->idx));
-
-	/* Kick guest if required. */
-	if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)
-			&& (vq->callfd >= 0))
-		eventfd_write(vq->callfd, (eventfd_t)1);
+	vhost_vring_call(vq);
 }
 
 static __rte_always_inline struct zcopy_mbuf *
-- 
2.14.3