Hello Xuan,
On Fri, Mar 22, 2024 at 10:00:22AM +0800, Xuan Zhuo wrote:
> On Thu, 21 Mar 2024 09:54:30 -0700, Breno Leitao <leitao@xxxxxxxxxx> wrote:
> > 4) Since the command above does not have a key, then the last
> > scatter-gatter entry will be zeroed, since rss_key_size == 0.
> > sg_buf_size = vi->rss_key_size;
>
>
>
> 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));
> vi->rss_key_size =
> virtio_cread8(vdev, offsetof(struct virtio_net_config, rss_max_key_size));
>
> vi->rss_hash_types_supported =
> virtio_cread32(vdev, offsetof(struct virtio_net_config, supported_hash_types));
> vi->rss_hash_types_supported &=
> ~(VIRTIO_NET_RSS_HASH_TYPE_IP_EX |
> VIRTIO_NET_RSS_HASH_TYPE_TCP_EX |
> VIRTIO_NET_RSS_HASH_TYPE_UDP_EX);
>
> dev->hw_features |= NETIF_F_RXHASH;
> }
>
>
> vi->rss_key_size is initiated here, I wonder if there is something wrong?
Not really, the code above is never executed (in my machines). This is
because `vi->has_rss` and `vi->has_rss_hash_report` are both unset.
Looking further, vdev does not have the VIRTIO_NET_F_RSS and
VIRTIO_NET_F_HASH_REPORT features.
Also, when I run `ethtool -x`, I got:
# ethtool -x eth0
RX flow hash indirection table for eth0 with 1 RX ring(s):
Operation not supported
RSS hash key:
Operation not supported
RSS hash function:
toeplitz: on
xor: off
crc32: off
