[dpdk-stable] [PATCH v5 1/4] vhost: fix missing memory table NUMA realloc

[Maxime Coquelin]

When the guest allocates virtqueues on a different NUMA node
than the one the Vhost metadata are allocated, both the Vhost
device struct and the virtqueues struct are reallocated.

However, reallocating the Vhost memory table was missing, which
likely causes at least one cross-NUMA accesses for every burst
of packets.

This patch reallocates this table on the same NUMA node as the
other metadata.

Fixes: 552e8fd3d2b4 ("vhost: simplify memory regions handling")
Cc: stable at dpdk.org

Reported-by: David Marchand <david.marchand at redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 lib/vhost/vhost_user.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 8f0eba6412..b5a84f3dcd 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -473,8 +473,8 @@ vhost_user_set_vring_num(struct virtio_net **pdev,
 }
 
 /*
- * Reallocate virtio_dev and vhost_virtqueue data structure to make them on the
- * same numa node as the memory of vring descriptor.
+ * Reallocate virtio_dev, vhost_virtqueue and related data structures to
+ * make them on the same numa node as the memory of vring descriptor.
  */
 #ifdef RTE_LIBRTE_VHOST_NUMA
 static struct virtio_net*
@@ -557,6 +557,9 @@ numa_realloc(struct virtio_net *dev, int index)
 		goto out;
 	}
 	if (oldnode != newnode) {
+		struct rte_vhost_memory *old_mem;
+		ssize_t mem_size;
+
 		VHOST_LOG_CONFIG(INFO,
 			"reallocate dev from %d to %d node\n",
 			oldnode, newnode);
@@ -568,6 +571,18 @@ numa_realloc(struct virtio_net *dev, int index)
 
 		memcpy(dev, old_dev, sizeof(*dev));
 		rte_free(old_dev);
+
+		mem_size = sizeof(struct rte_vhost_memory) +
+			sizeof(struct rte_vhost_mem_region) * dev->mem->nregions;
+		old_mem = dev->mem;
+		dev->mem = rte_malloc_socket(NULL, mem_size, 0, newnode);
+		if (!dev->mem) {
+			dev->mem = old_mem;
+			goto out;
+		}
+
+		memcpy(dev->mem, old_mem, mem_size);
+		rte_free(old_mem);
 	}
 
 out:
-- 
2.31.1