[dpdk-stable] [PATCH 2/7] vhost: fix missing guest pages 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 guest pages 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: e246896178e6 ("vhost: get guest/host physical address mappings")
Cc: stable at dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 lib/vhost/vhost_user.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 031e3bfa2f..cbfdf1b4d8 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -558,7 +558,8 @@ numa_realloc(struct virtio_net *dev, int index)
 	}
 	if (oldnode != newnode) {
 		struct rte_vhost_memory *old_mem;
-		ssize_t mem_size;
+		struct guest_page *old_gp;
+		ssize_t mem_size, gp_size;
 
 		VHOST_LOG_CONFIG(INFO,
 			"reallocate dev from %d to %d node\n",
@@ -583,6 +584,17 @@ numa_realloc(struct virtio_net *dev, int index)
 
 		memcpy(dev->mem, old_mem, mem_size);
 		rte_free(old_mem);
+
+		gp_size = dev->max_guest_pages * sizeof(*dev->guest_pages);
+		old_gp = dev->guest_pages;
+		dev->guest_pages = rte_malloc_socket(NULL, gp_size, RTE_CACHE_LINE_SIZE, newnode);
+		if (!dev->guest_pages) {
+			dev->guest_pages = old_gp;
+			goto out;
+		}
+
+		memcpy(dev->guest_pages, old_gp, gp_size);
+		rte_free(old_gp);
 	}
 
 out:
-- 
2.31.1