[RFC PATCH v4 13/17] net/sock: enable setting SO_ZEROCOPY for PF_VSOCK

From: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
To: Stefan Hajnoczi <stefanha@redhat.com>,
	Stefano Garzarella <sgarzare@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	Bobby Eshleman <bobby.eshleman@bytedance.com>
Cc: <kvm@vger.kernel.org>,
	<virtualization@lists.linux-foundation.org>,
	<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<kernel@sberdevices.ru>, <oxffffaa@gmail.com>,
	<avkrasnov@sberdevices.ru>,
	Arseniy Krasnov <AVKrasnov@sberdevices.ru>
Subject: [RFC PATCH v4 13/17] net/sock: enable setting SO_ZEROCOPY for PF_VSOCK
Date: Sat, 3 Jun 2023 23:49:35 +0300	[thread overview]
Message-ID: <20230603204939.1598818-14-AVKrasnov@sberdevices.ru> (raw)
In-Reply-To: <20230603204939.1598818-1-AVKrasnov@sberdevices.ru>

PF_VSOCK supports MSG_ZEROCOPY transmission, so SO_ZEROCOPY could
be enabled. PF_VSOCK implementation is a little bit special comparing to
PF_INET - MSG_ZEROCOPY support depends on transport layer of PF_VSOCK,
but here we can't "ask" its transport, so setting of this option is
always allowed, but if some transport doesn't support zerocopy tx, send
callback of PF_VSOCK will return -EOPNOTSUPP.

Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
 net/core/sock.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 5440e67bcfe3..d558e541e6d7 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1452,9 +1452,11 @@ int sk_setsockopt(struct sock *sk, int level, int optname,
 			      (sk->sk_type == SOCK_DGRAM &&
 			       sk->sk_protocol == IPPROTO_UDP)))
 				ret = -EOPNOTSUPP;
-		} else if (sk->sk_family != PF_RDS) {
+		} else if (sk->sk_family != PF_RDS &&
+			   sk->sk_family != PF_VSOCK) {
 			ret = -EOPNOTSUPP;
 		}
+
 		if (!ret) {
 			if (val < 0 || val > 1)
 				ret = -EINVAL;
-- 
2.25.1

