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Date:   Mon, 19 Sep 2022 19:24:54 +0000
From:   Jalal Mostafa <jalal.a.mostapha@gmail.com>
To:     netdev@vger.kernel.org, bpf@vger.kernel.org
Cc:     bjorn@kernel.org, magnus.karlsson@intel.com,
        maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com,
        davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
        pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net,
        hawk@kernel.org, john.fastabend@gmail.com,
        linux-kernel@vger.kernel.org, jalal.a.mostapha@gmail.com,
        jalal.mostafa@kit.edu
Subject: [PATCH bpf] xsk: inherit need_wakeup flag for shared sockets
Message-ID: <YyjCBjJch24OT+Ia@ipe420-102>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Precedence: bulk

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