On Wed, Mar 19, 2025 at 12:48 PM Akihiko Odaki <akihiko.od...@daynix.com> wrote:
>
> On 2025/03/19 10:43, Jason Wang wrote:
> > On Tue, Mar 18, 2025 at 5:57 PM Akihiko Odaki <akihiko.od...@daynix.com>
> > wrote:
> >>
> >> The new RSS configuration structures allow easily constructing data for
> >> VIRTIO_NET_CTRL_MQ_RSS_CONFIG as they strictly follow the order of data
> >> for the command.
> >>
> >> Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
> >> ---
> >> drivers/net/virtio_net.c | 117
> >> +++++++++++++++++------------------------------
> >> 1 file changed, 43 insertions(+), 74 deletions(-)
> >>
> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> >> index d1ed544ba03a..4153a0a5f278 100644
> >> --- a/drivers/net/virtio_net.c
> >> +++ b/drivers/net/virtio_net.c
> >> @@ -360,24 +360,7 @@ struct receive_queue {
> >> struct xdp_buff **xsk_buffs;
> >> };
> >>
> >> -/* This structure can contain rss message with maximum settings for
> >> indirection table and keysize
> >> - * Note, that default structure that describes RSS configuration
> >> virtio_net_rss_config
> >> - * contains same info but can't handle table values.
> >> - * In any case, structure would be passed to virtio hw through sg_buf
> >> split by parts
> >> - * because table sizes may be differ according to the device
> >> configuration.
> >> - */
> >> #define VIRTIO_NET_RSS_MAX_KEY_SIZE 40
> >> -struct virtio_net_ctrl_rss {
> >> - __le32 hash_types;
> >> - __le16 indirection_table_mask;
> >> - __le16 unclassified_queue;
> >> - __le16 hash_cfg_reserved; /* for HASH_CONFIG (see
> >> virtio_net_hash_config for details) */
> >> - __le16 max_tx_vq;
> >> - u8 hash_key_length;
> >> - u8 key[VIRTIO_NET_RSS_MAX_KEY_SIZE];
> >> -
> >> - __le16 *indirection_table;
> >> -};
> >>
> >> /* Control VQ buffers: protected by the rtnl lock */
> >> struct control_buf {
> >> @@ -421,7 +404,9 @@ struct virtnet_info {
> >> u16 rss_indir_table_size;
> >> u32 rss_hash_types_supported;
> >> u32 rss_hash_types_saved;
> >> - struct virtio_net_ctrl_rss rss;
> >> + struct virtio_net_rss_config_hdr *rss_hdr;
> >> + struct virtio_net_rss_config_trailer rss_trailer;
> >> + u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE];
> >>
> >> /* Has control virtqueue */
> >> bool has_cvq;
> >> @@ -523,23 +508,16 @@ enum virtnet_xmit_type {
> >> VIRTNET_XMIT_TYPE_XSK,
> >> };
> >>
> >> -static int rss_indirection_table_alloc(struct virtio_net_ctrl_rss *rss,
> >> u16 indir_table_size)
> >> +static size_t virtnet_rss_hdr_size(const struct virtnet_info *vi)
> >> {
> >> - if (!indir_table_size) {
> >> - rss->indirection_table = NULL;
> >> - return 0;
> >> - }
> >> + u16 indir_table_size = vi->has_rss ? vi->rss_indir_table_size : 1;
> >>
> >> - rss->indirection_table = kmalloc_array(indir_table_size,
> >> sizeof(u16), GFP_KERNEL);
> >> - if (!rss->indirection_table)
> >> - return -ENOMEM;
> >> -
> >> - return 0;
> >> + return struct_size(vi->rss_hdr, indirection_table,
> >> indir_table_size);
> >> }
> >>
> >> -static void rss_indirection_table_free(struct virtio_net_ctrl_rss *rss)
> >> +static size_t virtnet_rss_trailer_size(const struct virtnet_info *vi)
> >> {
> >> - kfree(rss->indirection_table);
> >> + return struct_size(&vi->rss_trailer, hash_key_data,
> >> vi->rss_key_size);
> >> }
> >>
> >> /* We use the last two bits of the pointer to distinguish the xmit type.
> >> */
> >> @@ -3576,15 +3554,16 @@ static void virtnet_rss_update_by_qpairs(struct
> >> virtnet_info *vi, u16 queue_pair
> >>
> >> for (; i < vi->rss_indir_table_size; ++i) {
> >> indir_val = ethtool_rxfh_indir_default(i, queue_pairs);
> >> - vi->rss.indirection_table[i] = cpu_to_le16(indir_val);
> >> + vi->rss_hdr->indirection_table[i] = cpu_to_le16(indir_val);
> >> }
> >> - vi->rss.max_tx_vq = cpu_to_le16(queue_pairs);
> >> + vi->rss_trailer.max_tx_vq = cpu_to_le16(queue_pairs);
> >> }
> >>
> >> static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs)
> >> {
> >> struct virtio_net_ctrl_mq *mq __free(kfree) = NULL;
> >> - struct virtio_net_ctrl_rss old_rss;
> >> + struct virtio_net_rss_config_hdr *old_rss_hdr;
> >> + struct virtio_net_rss_config_trailer old_rss_trailer;
> >> struct net_device *dev = vi->dev;
> >> struct scatterlist sg;
> >>
> >> @@ -3599,24 +3578,28 @@ static int virtnet_set_queues(struct virtnet_info
> >> *vi, u16 queue_pairs)
> >> * update (VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET below) and return
> >> directly.
> >> */
> >> if (vi->has_rss && !netif_is_rxfh_configured(dev)) {
> >> - memcpy(&old_rss, &vi->rss, sizeof(old_rss));
> >> - if (rss_indirection_table_alloc(&vi->rss,
> >> vi->rss_indir_table_size)) {
> >> - vi->rss.indirection_table =
> >> old_rss.indirection_table;
> >> + old_rss_hdr = vi->rss_hdr;
> >> + old_rss_trailer = vi->rss_trailer;
> >> + vi->rss_hdr = kmalloc(virtnet_rss_hdr_size(vi),
> >> GFP_KERNEL);
> >> + if (!vi->rss_hdr) {
> >> + vi->rss_hdr = old_rss_hdr;
> >> return -ENOMEM;
> >> }
> >>
> >> + *vi->rss_hdr = *old_rss_hdr;
> >> virtnet_rss_update_by_qpairs(vi, queue_pairs);
> >>
> >> if (!virtnet_commit_rss_command(vi)) {
> >> /* restore ctrl_rss if commit_rss_command failed
> >> */
> >> - rss_indirection_table_free(&vi->rss);
> >> - memcpy(&vi->rss, &old_rss, sizeof(old_rss));
> >> + kfree(vi->rss_hdr);
> >> + vi->rss_hdr = old_rss_hdr;
> >> + vi->rss_trailer = old_rss_trailer;
> >>
> >> dev_warn(&dev->dev, "Fail to set num of queue
> >> pairs to %d, because committing RSS failed\n",
> >> queue_pairs);
> >> return -EINVAL;
> >> }
> >> - rss_indirection_table_free(&old_rss);
> >> + kfree(old_rss_hdr);
> >> goto succ;
> >> }
> >>
> >> @@ -4059,28 +4042,12 @@ static int virtnet_set_ringparam(struct net_device
> >> *dev,
> >> static bool virtnet_commit_rss_command(struct virtnet_info *vi)
> >> {
> >> struct net_device *dev = vi->dev;
> >> - struct scatterlist sgs[4];
> >> - unsigned int sg_buf_size;
> >> + struct scatterlist sgs[2];
> >>
> >> /* prepare sgs */
> >> - sg_init_table(sgs, 4);
> >> -
> >> - sg_buf_size = offsetof(struct virtio_net_ctrl_rss,
> >> hash_cfg_reserved);
> >> - sg_set_buf(&sgs[0], &vi->rss, sg_buf_size);
> >> -
> >> - if (vi->has_rss) {
> >> - sg_buf_size = sizeof(uint16_t) * vi->rss_indir_table_size;
> >> - sg_set_buf(&sgs[1], vi->rss.indirection_table,
> >> sg_buf_size);
> >> - } else {
> >> - sg_set_buf(&sgs[1], &vi->rss.hash_cfg_reserved,
> >> sizeof(uint16_t));
> >> - }
> >> -
> >> - sg_buf_size = offsetof(struct virtio_net_ctrl_rss, key)
> >> - - offsetof(struct virtio_net_ctrl_rss, max_tx_vq);
> >> - sg_set_buf(&sgs[2], &vi->rss.max_tx_vq, sg_buf_size);
> >> -
> >> - sg_buf_size = vi->rss_key_size;
> >> - sg_set_buf(&sgs[3], vi->rss.key, sg_buf_size);
> >> + sg_init_table(sgs, 2);
> >> + sg_set_buf(&sgs[0], vi->rss_hdr, virtnet_rss_hdr_size(vi));
> >> + sg_set_buf(&sgs[1], &vi->rss_trailer,
> >> virtnet_rss_trailer_size(vi));
> >
> > So I still see this:
> >
> > if (vi->has_rss || vi->has_rss_hash_report) {
> > if (!virtnet_commit_rss_command(vi)) {
> >
> > Should we introduce a hash config helper instead?
>
> I think it's fine to use virtnet_commit_rss_command() for hash
> reporting. struct virtio_net_hash_config and struct
> virtio_net_rss_config are defined to have a common layout to allow
> sharing this kind of logic.
Well, this trick won't work if the reserved field in hash_config is
used in the future.
Thanks
>
> Regards,
> Akihiko Odaki
>
> >
> > Thanks
> >
>
