Stefano Garzarella
2023-Jul-06 16:56 UTC
[RFC PATCH v5 13/17] vsock: enable setting SO_ZEROCOPY
On Sat, Jul 01, 2023 at 09:39:43AM +0300, Arseniy Krasnov wrote:>For AF_VSOCK, zerocopy tx mode depends on transport, so this option must >be set in AF_VSOCK implementation where transport is accessible (if >transport is not set during setting SO_ZEROCOPY: for example socket is >not connected, then SO_ZEROCOPY will be enabled, but once transport will >be assigned, support of this type of transmission will be checked). > >To handle SO_ZEROCOPY, AF_VSOCK implementation uses SOCK_CUSTOM_SOCKOPT >bit, thus handling SOL_SOCKET option operations, but all of them except >SO_ZEROCOPY will be forwarded to the generic handler by calling >'sock_setsockopt()'. > >Signed-off-by: Arseniy Krasnov <AVKrasnov at sberdevices.ru> >--- > Changelog: > v4 -> v5: > * This patch is totally reworked. Previous version added check for > PF_VSOCK directly to 'net/core/sock.c', thus allowing to set > SO_ZEROCOPY for AF_VSOCK type of socket. This new version catches > attempt to set SO_ZEROCOPY in 'af_vsock.c'. All other options > except SO_ZEROCOPY are forwarded to generic handler. Only this > option is processed in 'af_vsock.c'. Handling this option includes > access to transport to check that MSG_ZEROCOPY transmission is > supported by the current transport (if it is set, if not - transport > will be checked during 'connect()').Yeah, great, this is much better!> > net/vmw_vsock/af_vsock.c | 44 ++++++++++++++++++++++++++++++++++++++-- > 1 file changed, 42 insertions(+), 2 deletions(-) > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >index da22ae0ef477..8acc77981d01 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -1406,8 +1406,18 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr, > goto out; > } > >- if (vsock_msgzerocopy_allow(transport)) >+ if (!vsock_msgzerocopy_allow(transport)) {Can you leave `if (vsock_msgzerocopy_allow(transport))` and just add the else branch with this new check? if (vsock_msgzerocopy_allow(transport)) { ... } else if (sock_flag(sk, SOCK_ZEROCOPY)) { ... }>+ /* If this option was set before 'connect()', >+ * when transport was unknown, check that this >+ * feature is supported here. >+ */ >+ if (sock_flag(sk, SOCK_ZEROCOPY)) { >+ err = -EOPNOTSUPP; >+ goto out; >+ } >+ } else { > set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags); >+ } > > err = vsock_auto_bind(vsk); > if (err) >@@ -1643,7 +1653,7 @@ static int vsock_connectible_setsockopt(struct socket *sock, > const struct vsock_transport *transport; > u64 val; > >- if (level != AF_VSOCK) >+ if (level != AF_VSOCK && level != SOL_SOCKET) > return -ENOPROTOOPT; > > #define COPY_IN(_v) \ >@@ -1666,6 +1676,34 @@ static int vsock_connectible_setsockopt(struct socket *sock, > > transport = vsk->transport; > >+ if (level == SOL_SOCKET) {We could reduce the indentation here: if (optname != SO_ZEROCOPY) { release_sock(sk); return sock_setsockopt(sock, level, optname, optval, optlen); } Then remove the next indentation.>+ if (optname == SO_ZEROCOPY) { >+ int zc_val;`zerocopy` is more readable.>+ >+ /* Use 'int' type here, because variable to >+ * set this option usually has this type. >+ */ >+ COPY_IN(zc_val); >+ >+ if (zc_val < 0 || zc_val > 1) { >+ err = -EINVAL; >+ goto exit; >+ } >+ >+ if (transport && !vsock_msgzerocopy_allow(transport)) { >+ err = -EOPNOTSUPP; >+ goto exit; >+ } >+ >+ sock_valbool_flag(sk, SOCK_ZEROCOPY, >+ zc_val ? true : false);Why not using directly `zc_val`? The 3rd param of sock_valbool_flag() is an int.>+ goto exit; >+ } >+ >+ release_sock(sk); >+ return sock_setsockopt(sock, level, optname, optval, optlen); >+ } >+ > switch (optname) { > case SO_VM_SOCKETS_BUFFER_SIZE: > COPY_IN(val); >@@ -2321,6 +2359,8 @@ static int vsock_create(struct net *net, struct socket *sock, > } > } > >+ set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags); >+ > vsock_insert_unbound(vsk); > > return 0; >-- >2.25.1 >