Re: [PATCH net-next v9 04/14] netdev: support binding dma-buf to netdevice

On 2024-05-10 16:21, Mina Almasry wrote:

-/* Stub */ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) {

• return 0;

• struct nlattr *tb[ARRAY_SIZE(netdev_queue_dmabuf_nl_policy)];
• struct net_devmem_dmabuf_binding *out_binding;
• struct list_head *sock_binding_list;
• u32 ifindex, dmabuf_fd, rxq_idx;
• struct net_device *netdev;
• struct sk_buff *rsp;
• struct nlattr *attr;
• int rem, err = 0;
• void *hdr;
• if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_DEV_IFINDEX) ||

•    GENL_REQ_ATTR_CHECK(info, NETDEV_A_BIND_DMABUF_DMABUF_FD) ||
  

•    GENL_REQ_ATTR_CHECK(info, NETDEV_A_BIND_DMABUF_QUEUES))
  

• return -EINVAL;
  

• ifindex = nla_get_u32(info->attrs[NETDEV_A_DEV_IFINDEX]);
• dmabuf_fd = nla_get_u32(info->attrs[NETDEV_A_BIND_DMABUF_DMABUF_FD]);
• rtnl_lock();
• netdev = __dev_get_by_index(genl_info_net(info), ifindex);
• if (!netdev) {

• err = -ENODEV;
  

• goto err_unlock;
  

• }
• err = net_devmem_bind_dmabuf(netdev, dmabuf_fd, &out_binding);
• if (err)

• goto err_unlock;
  

• nla_for_each_attr(attr, genlmsg_data(info->genlhdr),

• 	  genlmsg_len(info->genlhdr), rem) {
  

• if (nla_type(attr) != NETDEV_A_BIND_DMABUF_QUEUES)
  

• 	continue;
  

• err = nla_parse_nested(
  

• 	tb, ARRAY_SIZE(netdev_queue_dmabuf_nl_policy) - 1, attr,
  

• 	netdev_queue_dmabuf_nl_policy, info->extack);
  

• if (err < 0)
  

• 	goto err_unbind;
  

• rxq_idx = nla_get_u32(tb[NETDEV_A_QUEUE_DMABUF_IDX]);
  

• if (rxq_idx >= netdev->num_rx_queues) {
  

• 	err = -ERANGE;
  

• 	goto err_unbind;
  

• }
  

net_devmem_bind_dmabuf_to_queue() checks for rxq_idx >= netdev->num_rx_queues as well. I'd say remove the one in netdev_nl_bind_rx_doit().

Also we may want a generic netdev function e.g. netdev_rx_queue_set_mp() since I need the same functionality.

• err = net_devmem_bind_dmabuf_to_queue(netdev, rxq_idx,
  

• 				      out_binding);
  

• if (err)
  

• 	goto err_unbind;
  

• }
• sock_binding_list = genl_sk_priv_get(&netdev_nl_family,

• 			     NETLINK_CB(skb).sk);
  

• if (IS_ERR(sock_binding_list)) {

• err = PTR_ERR(sock_binding_list);
  

• goto err_unbind;
  

• }
• list_add(&out_binding->list, sock_binding_list);
• rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
• if (!rsp) {

• err = -ENOMEM;
  

• goto err_unbind;
  

• }
• hdr = genlmsg_iput(rsp, info);
• if (!hdr) {

• err = -EMSGSIZE;
  

• goto err_genlmsg_free;
  

• }
• nla_put_u32(rsp, NETDEV_A_BIND_DMABUF_DMABUF_ID, out_binding->id);
• genlmsg_end(rsp, hdr);
• rtnl_unlock();
• return genlmsg_reply(rsp, info);

+err_genlmsg_free:

• nlmsg_free(rsp);

+err_unbind:

• net_devmem_unbind_dmabuf(out_binding);

+err_unlock:

• rtnl_unlock();
• return err;

}