[dpdk-dev] [PATCH] vhost: make iotlb cache name unique among multi processes

[Itsuro Oda]

Currently, iotlb cache name is comprised of vid and virtqueue
index. For example, "iotlb_cache_0_0". Because vid is assigned
per process, iotlb cache name is not unique among multi processes.
For example a secondary process uses a vhost
(ex. eth_vhost0,iface=/tmp/sock0) and another secondary process
uses a vhost (ex. eth_vhost1,iface=/tmp/sock1), iotlb cache
name of both vhost ("iotlb_cache_0_0") are same and as a result
iotlb cache is broken.

This patch makes iotlb cache name unique among milti processes
by using the interface name not vid to comprise iotlb cache name.
Since the length of interface name is variable, this patch uses
hash value calculated by the interface name.

Fixes: d012d1f293f4 (vhost: add IOTLB helper functions)
Cc: stable at dpdk.org

Signed-off-by: Itsuro Oda <oda at valinux.co.jp>
---
 lib/librte_vhost/iotlb.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/iotlb.c b/lib/librte_vhost/iotlb.c
index bc1758528..0992c145b 100644
--- a/lib/librte_vhost/iotlb.c
+++ b/lib/librte_vhost/iotlb.c
@@ -6,6 +6,7 @@
 #include <numaif.h>
 #endif
 
+#include <rte_jhash.h>
 #include <rte_tailq.h>
 
 #include "iotlb.h"
@@ -288,6 +289,7 @@ vhost_user_iotlb_init(struct virtio_net *dev, int vq_index)
 	char pool_name[RTE_MEMPOOL_NAMESIZE];
 	struct vhost_virtqueue *vq = dev->virtqueue[vq_index];
 	int socket = 0;
+	uint32_t val;
 
 	if (vq->iotlb_pool) {
 		/*
@@ -308,8 +310,10 @@ vhost_user_iotlb_init(struct virtio_net *dev, int vq_index)
 	TAILQ_INIT(&vq->iotlb_list);
 	TAILQ_INIT(&vq->iotlb_pending_list);
 
-	snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%d_%d",
-			dev->vid, vq_index);
+	val = rte_jhash(dev->ifname, strlen(dev->ifname), 0);
+	snprintf(pool_name, sizeof(pool_name), "iotlb_cache_%08x_%d",
+			val, vq_index);
+	VHOST_LOG_CONFIG(DEBUG, "IOTLB cache name: %s\n", pool_name);
 
 	/* If already created, free it and recreate */
 	vq->iotlb_pool = rte_mempool_lookup(pool_name);
-- 
2.17.0