[dpdk-stable] [PATCH v4 4/7] vhost: fix NUMA reallocation with multiqueue

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Since the Vhost-user device initialization has been reworked,
enabling the application to start using the device as soon as
the first queue pair is ready, NUMA reallocation no more
happened on queue pairs other than the first one since
numa_realloc() was returning early if the device was running.

This patch fixes this issue by only preventing the device
metadata to be allocated if the device is running. For the
virtqueues, a vring state change notification is sent to
notify the application of its disablement. Since the callback
is supposed to be blocking, it is safe to reallocate it
afterwards.

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost_user.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 0e9e26ebe0..6e7b327ef8 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -488,9 +488,6 @@ numa_realloc(struct virtio_net *dev, int index)
 	struct batch_copy_elem *new_batch_copy_elems;
 	int ret;
 
-	if (dev->flags & VIRTIO_DEV_RUNNING)
-		return dev;
-
 	old_dev = dev;
 	vq = old_vq = dev->virtqueue[index];
 
@@ -506,6 +503,11 @@ numa_realloc(struct virtio_net *dev, int index)
 		return dev;
 	}
 	if (oldnode != newnode) {
+		if (vq->ready) {
+			vq->ready = false;
+			vhost_user_notify_queue_state(dev, index, 0);
+		}
+
 		VHOST_LOG_CONFIG(INFO,
 			"reallocate vq from %d to %d node\n", oldnode, newnode);
 		vq = rte_malloc_socket(NULL, sizeof(*vq), 0, newnode);
@@ -558,6 +560,9 @@ numa_realloc(struct virtio_net *dev, int index)
 		rte_free(old_vq);
 	}
 
+	if (dev->flags & VIRTIO_DEV_RUNNING)
+		goto out;
+
 	/* check if we need to reallocate dev */
 	ret = get_mempolicy(&oldnode, NULL, 0, old_dev,
 			    MPOL_F_NODE | MPOL_F_ADDR);
-- 
2.31.1