[RFC PATCH v3 08/17] vsock: check for MSG_ZEROCOPY support
From: Arseniy Krasnov <hidden>
Date: 2023-05-22 07:45:45
Also in:
kvm, lkml
Subsystem:
networking [general], the rest, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefano Garzarella
This feature totally depends on transport, so if transport doesn't support it, return error. Signed-off-by: Arseniy Krasnov <redacted> --- include/net/af_vsock.h | 7 +++++++ net/vmw_vsock/af_vsock.c | 6 ++++++ 2 files changed, 13 insertions(+)
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 0e7504a42925..ec09edc5f3a0 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h@@ -177,6 +177,9 @@ struct vsock_transport { /* Read a single skb */ int (*read_skb)(struct vsock_sock *, skb_read_actor_t); + + /* Zero-copy. */ + bool (*msgzerocopy_allow)(void); }; /**** CORE ****/
@@ -243,4 +246,8 @@ static inline void __init vsock_bpf_build_proto(void) {} #endif +static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t) +{ + return t->msgzerocopy_allow && t->msgzerocopy_allow(); +} #endif /* __AF_VSOCK_H__ */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index b2da791d920b..dbfe82ee7769 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c@@ -1824,6 +1824,12 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg, goto out; } + if (msg->msg_flags & MSG_ZEROCOPY && + !vsock_msgzerocopy_allow(transport)) { + err = -EOPNOTSUPP; + goto out; + } + /* Wait for room in the produce queue to enqueue our user's data. */ timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
--
2.25.1