virtio-net: Ensure queue index fits with RSS

Ensure the queue index points to a valid queue when software RSS enabled. The new calculation matches with the behavior of Linux's TAP device with the RSS eBPF program. Fixes: 4474e37 ("virtio-net: implement RX RSS processing") Reported-by: Zhibin Hu <[email protected]> Cc: [email protected] Signed-off-by: Akihiko Odaki <[email protected]> Reviewed-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Jason Wang <[email protected]>
stweil · Aug 2, 2024 · f1595ce · f1595ce
1 parent 9e3b9f2
commit f1595ce
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
@@ -1905,7 +1905,8 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
     if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
         int index = virtio_net_process_rss(nc, buf, size, &extra_hdr);
         if (index >= 0) {
-            NetClientState *nc2 = qemu_get_subqueue(n->nic, index);
+            NetClientState *nc2 =
+                qemu_get_subqueue(n->nic, index % n->curr_queue_pairs);
             return virtio_net_receive_rcu(nc2, buf, size, true);
         }
     }