Den tors 26 juli 2018 kl 23:44 skrev Jakub Kicinski
<jakub.kicin...@netronome.com>:
>
> Currently drivers have to check if they already have a umem
> installed for a given queue and return an error if so. Make
> better use of XDP_QUERY_XSK_UMEM and move this functionality
> to the core.
>
> We need to keep rtnl across the calls now.
>
> Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
> Reviewed-by: Quentin Monnet <quentin.mon...@netronome.com>
> ---
> include/linux/netdevice.h | 7 ++++---
> net/xdp/xdp_umem.c | 37 ++++++++++++++++++++++++++++---------
> 2 files changed, 32 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> index 6717dc7e8fbf..a5a34f0fb485 100644
> --- a/include/linux/netdevice.h
> +++ b/include/linux/netdevice.h
> @@ -872,10 +872,10 @@ struct netdev_bpf {
> struct {
> struct bpf_offloaded_map *offmap;
> };
> - /* XDP_SETUP_XSK_UMEM */
> + /* XDP_QUERY_XSK_UMEM, XDP_SETUP_XSK_UMEM */
> struct {
> - struct xdp_umem *umem;
> - u16 queue_id;
> + struct xdp_umem *umem; /* out for query*/
> + u16 queue_id; /* in for query */
> } xsk;
> };
> };
> @@ -3566,6 +3566,7 @@ int dev_change_xdp_fd(struct net_device *dev, struct
> netlink_ext_ack *extack,
> int fd, u32 flags);
> u32 __dev_xdp_query(struct net_device *dev, bpf_op_t xdp_op,
> enum bpf_netdev_command cmd);
> +int xdp_umem_query(struct net_device *dev, u16 queue_id);
>
> int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
> int dev_forward_skb(struct net_device *dev, struct sk_buff *skb);
> diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c
> index c199d66b5f3f..911ca6d3cb5a 100644
> --- a/net/xdp/xdp_umem.c
> +++ b/net/xdp/xdp_umem.c
> @@ -11,6 +11,8 @@
> #include <linux/slab.h>
> #include <linux/bpf.h>
> #include <linux/mm.h>
> +#include <linux/netdevice.h>
> +#include <linux/rtnetlink.h>
>
> #include "xdp_umem.h"
> #include "xsk_queue.h"
> @@ -40,6 +42,21 @@ void xdp_del_sk_umem(struct xdp_umem *umem, struct
> xdp_sock *xs)
> }
> }
>
> +int xdp_umem_query(struct net_device *dev, u16 queue_id)
> +{
> + struct netdev_bpf bpf;
> +
> + ASSERT_RTNL();
> +
> + memset(&bpf, 0, sizeof(bpf));
> + bpf.command = XDP_QUERY_XSK_UMEM;
> + bpf.xsk.queue_id = queue_id;
> +
> + if (!dev->netdev_ops->ndo_bpf)
> + return 0;
> + return dev->netdev_ops->ndo_bpf(dev, &bpf) ?: !!bpf.xsk.umem;
> +}
> +
> int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
> u32 queue_id, u16 flags)
> {
> @@ -62,28 +79,30 @@ int xdp_umem_assign_dev(struct xdp_umem *umem, struct
> net_device *dev,
> bpf.command = XDP_QUERY_XSK_UMEM;
>
> rtnl_lock();
> - err = dev->netdev_ops->ndo_bpf(dev, &bpf);
> - rtnl_unlock();
> -
> - if (err)
> - return force_zc ? -ENOTSUPP : 0;
> + err = xdp_umem_query(dev, queue_id);
> + if (err) {
> + err = err < 0 ? -ENOTSUPP : -EBUSY;
> + goto err_rtnl_unlock;
> + }
>
> bpf.command = XDP_SETUP_XSK_UMEM;
> bpf.xsk.umem = umem;
> bpf.xsk.queue_id = queue_id;
>
> - rtnl_lock();
> err = dev->netdev_ops->ndo_bpf(dev, &bpf);
> - rtnl_unlock();
> -
> if (err)
> - return force_zc ? err : 0; /* fail or fallback */
> + goto err_rtnl_unlock;
> + rtnl_unlock();
>
> dev_hold(dev);
> umem->dev = dev;
> umem->queue_id = queue_id;
> umem->zc = true;
> return 0;
> +
> +err_rtnl_unlock:
> + rtnl_unlock();
> + return force_zc ? err : 0; /* fail or fallback */
> }
>
> static void xdp_umem_clear_dev(struct xdp_umem *umem)
> --
> 2.17.1
>
Nice!
For a non-RFC version,
Acked-by: Björn Töpel <bjorn.to...@intel.com>
