[dpdk-dev] [PATCH 1/3] vhost: do not realloc device and queues during running

Tiwei Bie tiwei.bie at intel.com
Mon Aug 19 13:34:55 CEST 2019

When the device has been started, don't do the reallocation anymore.
Otherwise the pointers used in application threads can be invalidated
without proper protection. Instead of introducing a global lock to
protect the change of device pointers which will hurt the performance,
let's just do the reallocation during setup.

Fixes: af295ad4698c ("vhost: realloc device and queues to same numa node as vring desc")
Cc: stable at dpdk.org

Reported-by: Yinan Wang <yinan.wang at intel.com>
Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
 lib/librte_vhost/vhost_user.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 0b72648a5..ea43ab139 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -410,6 +410,9 @@ 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];

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