[dpdk-dev] [PATCH v3 2/3] net/virtio: update memory ordering comment for vq notify

Ilya Maximets i.maximets at samsung.com
Wed Jan 9 15:50:14 CET 2019


We're not using io ports in case of modern device even on IA.
Also, this comment useless for other architectures.

Signed-off-by: Ilya Maximets <i.maximets at samsung.com>
---
 drivers/net/virtio/virtqueue.h | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index dffa03669..53aeac238 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -437,14 +437,13 @@ virtqueue_kick_prepare_packed(struct virtqueue *vq)
 	return flags != RING_EVENT_FLAGS_DISABLE;
 }
 
+/*
+ * virtqueue_kick_prepare*() or the virtio_wmb() should be called
+ * before this function to be sure that all the data is visible to vhost.
+ */
 static inline void
 virtqueue_notify(struct virtqueue *vq)
 {
-	/*
-	 * Ensure updated avail->idx is visible to host.
-	 * For virtio on IA, the notificaiton is through io port operation
-	 * which is a serialization instruction itself.
-	 */
 	VTPCI_OPS(vq->hw)->notify_queue(vq->hw, vq);
 }
 
-- 
2.17.1



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