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* [PATCH bpf] xsk: inherit need_wakeup flag for shared sockets
@ 2022-09-19 19:24 Jalal Mostafa
  2022-09-20  6:27 ` Magnus Karlsson
  0 siblings, 1 reply; 2+ messages in thread
From: Jalal Mostafa @ 2022-09-19 19:24 UTC (permalink / raw)
  To: netdev, bpf
  Cc: bjorn, magnus.karlsson, maciej.fijalkowski, jonathan.lemon,
	davem, edumazet, kuba, pabeni, ast, daniel, hawk, john.fastabend,
	linux-kernel, jalal.a.mostapha, jalal.mostafa

The flag for need_wakeup is not set for xsks with `XDP_SHARED_UMEM`
flag and of different queue ids and/or devices. They should inherit
the flag from the first socket buffer pool since no flags can be
specified once `XDP_SHARED_UMEM` is specified. The issue is fixed
by creating a new function `xp_create_and_assign_umem_shared` to
create xsk_buff_pool for xsks with the shared umem flag set.

Signed-off-by: Jalal Mostafa <jalal.a.mostapha@gmail.com>
---
 include/net/xsk_buff_pool.h |  2 ++
 net/xdp/xsk.c               |  3 +--
 net/xdp/xsk_buff_pool.c     | 15 +++++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
index 647722e847b4..917cfef9d355 100644
--- a/include/net/xsk_buff_pool.h
+++ b/include/net/xsk_buff_pool.h
@@ -93,6 +93,8 @@ struct xsk_buff_pool {
 /* AF_XDP core. */
 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 						struct xdp_umem *umem);
+struct xsk_buff_pool *xp_create_and_assign_umem_shared(struct xdp_sock *xs,
+						       struct xdp_sock *umem_xs);
 int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
 		  u16 queue_id, u16 flags);
 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem,
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 5b4ce6ba1bc7..a415db88e8e5 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -946,8 +946,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
 			/* Share the umem with another socket on another qid
 			 * and/or device.
 			 */
-			xs->pool = xp_create_and_assign_umem(xs,
-							     umem_xs->umem);
+			xs->pool = xp_create_and_assign_umem_shared(xs, umem_xs);
 			if (!xs->pool) {
 				err = -ENOMEM;
 				sockfd_put(sock);
diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
index a71a8c6edf55..7d5b0bd8d953 100644
--- a/net/xdp/xsk_buff_pool.c
+++ b/net/xdp/xsk_buff_pool.c
@@ -112,6 +112,21 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
 	return NULL;
 }
 
+struct xsk_buff_pool *xp_create_and_assign_umem_shared(struct xdp_sock *xs,
+						       struct xdp_sock *umem_xs)
+{
+	struct xdp_umem *umem = umem_xs->umem;
+	struct xsk_buff_pool *pool = xp_create_and_assign_umem(xs, umem);
+
+	if (!pool)
+		goto out;
+
+	pool->uses_need_wakeup = umem_xs->pool->uses_need_wakeup;
+
+out:
+	return pool;
+}
+
 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
 {
 	u32 i;
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH bpf] xsk: inherit need_wakeup flag for shared sockets
  2022-09-19 19:24 [PATCH bpf] xsk: inherit need_wakeup flag for shared sockets Jalal Mostafa
@ 2022-09-20  6:27 ` Magnus Karlsson
  0 siblings, 0 replies; 2+ messages in thread
From: Magnus Karlsson @ 2022-09-20  6:27 UTC (permalink / raw)
  To: Jalal Mostafa
  Cc: netdev, bpf, bjorn, magnus.karlsson, maciej.fijalkowski,
	jonathan.lemon, davem, edumazet, kuba, pabeni, ast, daniel, hawk,
	john.fastabend, linux-kernel, jalal.mostafa

On Mon, Sep 19, 2022 at 9:27 PM Jalal Mostafa
<jalal.a.mostapha@gmail.com> wrote:
>
> The flag for need_wakeup is not set for xsks with `XDP_SHARED_UMEM`
> flag and of different queue ids and/or devices. They should inherit
> the flag from the first socket buffer pool since no flags can be
> specified once `XDP_SHARED_UMEM` is specified. The issue is fixed
> by creating a new function `xp_create_and_assign_umem_shared` to
> create xsk_buff_pool for xsks with the shared umem flag set.

Thanks for spotting this Jalal. Though I think we should aim for a
simpler fix. The uses_need_wakeup flag is set by xp_assign_dev(). The
problem here is the function xp_assign_dev_shared() that prepares the
flag parameter for xp_assign_dev().

if (pool->uses_need_wakeup)
                flags |= XDP_USE_NEED_WAKEUP;

Should really be:

if (umem_xs->pool->uses_need_wakeup)
                flags |= XDP_USE_NEED_WAKEUP;

So change the function parameter *umem to *umem_xs, use that in the
function call and do:

flags = umem_xs->umem->zc ? XDP_ZEROCOPY : XDP_COPY;
if (umem_xs->pool->uses_need_wakeup)
          flags |= XDP_USE_NEED_WAKEUP;

What do you think?

> Signed-off-by: Jalal Mostafa <jalal.a.mostapha@gmail.com>
> ---
>  include/net/xsk_buff_pool.h |  2 ++
>  net/xdp/xsk.c               |  3 +--
>  net/xdp/xsk_buff_pool.c     | 15 +++++++++++++++
>  3 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
> index 647722e847b4..917cfef9d355 100644
> --- a/include/net/xsk_buff_pool.h
> +++ b/include/net/xsk_buff_pool.h
> @@ -93,6 +93,8 @@ struct xsk_buff_pool {
>  /* AF_XDP core. */
>  struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
>                                                 struct xdp_umem *umem);
> +struct xsk_buff_pool *xp_create_and_assign_umem_shared(struct xdp_sock *xs,
> +                                                      struct xdp_sock *umem_xs);
>  int xp_assign_dev(struct xsk_buff_pool *pool, struct net_device *dev,
>                   u16 queue_id, u16 flags);
>  int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem,
> diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
> index 5b4ce6ba1bc7..a415db88e8e5 100644
> --- a/net/xdp/xsk.c
> +++ b/net/xdp/xsk.c
> @@ -946,8 +946,7 @@ static int xsk_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
>                         /* Share the umem with another socket on another qid
>                          * and/or device.
>                          */
> -                       xs->pool = xp_create_and_assign_umem(xs,
> -                                                            umem_xs->umem);
> +                       xs->pool = xp_create_and_assign_umem_shared(xs, umem_xs);
>                         if (!xs->pool) {
>                                 err = -ENOMEM;
>                                 sockfd_put(sock);
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index a71a8c6edf55..7d5b0bd8d953 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -112,6 +112,21 @@ struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
>         return NULL;
>  }
>
> +struct xsk_buff_pool *xp_create_and_assign_umem_shared(struct xdp_sock *xs,
> +                                                      struct xdp_sock *umem_xs)
> +{
> +       struct xdp_umem *umem = umem_xs->umem;
> +       struct xsk_buff_pool *pool = xp_create_and_assign_umem(xs, umem);
> +
> +       if (!pool)
> +               goto out;
> +
> +       pool->uses_need_wakeup = umem_xs->pool->uses_need_wakeup;
> +
> +out:
> +       return pool;
> +}
> +
>  void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
>  {
>         u32 i;
> --
> 2.34.1
>

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2022-09-20  6:28 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
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2022-09-19 19:24 [PATCH bpf] xsk: inherit need_wakeup flag for shared sockets Jalal Mostafa
2022-09-20  6:27 ` Magnus Karlsson

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