[dpdk-dev] [PATCH 1/6] vhost: fix missing memory table NUMA realloc

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

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 iat 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@dpdk.org

Reported-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost_user.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 8f0eba6412..031e3bfa2f 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -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