On Thu, Mar 20, 2025 at 1:36 PM Akihiko Odaki <akihiko.od...@daynix.com> wrote:
>
> On 2025/03/20 10:50, Jason Wang wrote:
> > 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.
>
> Right, but we can add a hash config helper when that happens. It will
> only result in a duplication of logic for now.
>
> Regards,
> Akihiko Odaki
That's tricky as the cvq commands were designed to be used separately.
Let's use a separate helper and virtio_net_hash_config uAPIs now.
Thanks
>
> >
> > Thanks
> >
> >>
> >> Regards,
> >> Akihiko Odaki
> >>
> >>>
> >>> Thanks
> >>>
> >>
> >
>
