[PULL 4/6] virtio-net: Fix hash reporting when the queue changes

[Jason Wang <jasowang@redhat.com>]

From: Akihiko Odaki <akihiko.odaki@daynix.com>

virtio_net_process_rss() fills the values used for hash reporting, but
the values used to be thrown away with a recursive function call if
the queue changes after RSS. Avoid the function call to keep the values.

Fixes: a4c960eedcd2 ("virtio-net: Do not write hashes to peer buffer")
Buglink: https://issues.redhat.com/browse/RHEL-59572
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 hw/net/virtio-net.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index d4aaf362b7..b544d2e91a 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -1898,10 +1898,10 @@ static int virtio_net_process_rss(NetClientState *nc, const uint8_t *buf,
 }
 
 static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
-                                      size_t size, bool no_rss)
+                                      size_t size)
 {
     VirtIONet *n = qemu_get_nic_opaque(nc);
-    VirtIONetQueue *q = virtio_net_get_subqueue(nc);
+    VirtIONetQueue *q;
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     VirtQueueElement *elems[VIRTQUEUE_MAX_SIZE];
     size_t lens[VIRTQUEUE_MAX_SIZE];
@@ -1911,12 +1911,10 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
     size_t offset, i, guest_offset, j;
     ssize_t err;
 
-    if (!no_rss && n->rss_data.enabled && n->rss_data.enabled_software_rss) {
+    if (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 % n->curr_queue_pairs);
-            return virtio_net_receive_rcu(nc2, buf, size, true);
+            nc = qemu_get_subqueue(n->nic, index % n->curr_queue_pairs);
         }
     }
 
@@ -1924,6 +1922,8 @@ static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
         return -1;
     }
 
+    q = virtio_net_get_subqueue(nc);
+
     /* hdr_len refers to the header we supply to the guest */
     if (!virtio_net_has_buffers(q, size + n->guest_hdr_len - n->host_hdr_len)) {
         return 0;
@@ -2049,7 +2049,7 @@ static ssize_t virtio_net_do_receive(NetClientState *nc, const uint8_t *buf,
 {
     RCU_READ_LOCK_GUARD();
 
-    return virtio_net_receive_rcu(nc, buf, size, false);
+    return virtio_net_receive_rcu(nc, buf, size);
 }
 
 /*
-- 
2.42.0