[PATCH net v2 1/2] virtio_net: Do not set rss_indir if RSS is not supported

[Breno Leitao]

Do not set virtnet_info->rss_indir_table_size if RSS is not available
for the device.

Currently, rss_indir_table_size is set if either has_rss or
has_rss_hash_report is available, but, it should only be set if has_rss
is set.

On the virtnet_set_rxfh(), return an invalid command if the request has
indirection table set, but virtnet does not support RSS.

Suggested-by: Heng Qi <hengqi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Breno Leitao <leitao@xxxxxxxxxx>
---
 drivers/net/virtio_net.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c22d1118a133..c640fdf28fc5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3813,6 +3813,9 @@ static int virtnet_set_rxfh(struct net_device *dev,
 	    rxfh->hfunc != ETH_RSS_HASH_TOP)
 		return -EOPNOTSUPP;
 
+	if (rxfh->indir && !vi->has_rss)
+		return -EINVAL;
+
 	if (rxfh->indir) {
 		for (i = 0; i < vi->rss_indir_table_size; ++i)
 			vi->ctrl->rss.indirection_table[i] = rxfh->indir[i];
@@ -4729,13 +4732,15 @@ static int virtnet_probe(struct virtio_device *vdev)
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT))
 		vi->has_rss_hash_report = true;
 
-	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS))
+	if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) {
 		vi->has_rss = true;
 
-	if (vi->has_rss || vi->has_rss_hash_report) {
 		vi->rss_indir_table_size =
 			virtio_cread16(vdev, offsetof(struct virtio_net_config,
 				rss_max_indirection_table_length));
+	}
+
+	if (vi->has_rss || vi->has_rss_hash_report) {
 		vi->rss_key_size =
 			virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
 
-- 
2.43.0