On 26.09.2023 15:56, Stefano Garzarella wrote:
> On Fri, Sep 22, 2023 at 08:24:24AM +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@xxxxxxxxxxxxxxxxx>
>> ---
>> Changelog:
>> v5(big patchset) -> v1:
>> * Compact 'if' conditions.
>> * Rename 'zc_val' to 'zerocopy'.
>> * Use 'zerocopy' value directly in 'sock_valbool_flag()', without
>> ?: operator.
>> * Set 'SOCK_CUSTOM_SOCKOPT' bit for connectible sockets only, as
>> suggested by Bobby Eshleman <bobbyeshleman@xxxxxxxxx>.
>>
>> net/vmw_vsock/af_vsock.c | 46 ++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 44 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>> index 482300eb88e0..c05a42e02a17 100644
>> --- a/net/vmw_vsock/af_vsock.c
>> +++ b/net/vmw_vsock/af_vsock.c
>> @@ -1406,8 +1406,16 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr,
>> goto out;
>> }
>>
>> - if (vsock_msgzerocopy_allow(transport))
>> + if (vsock_msgzerocopy_allow(transport)) {
>> set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
>> + } 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.
>> + */
>> + err = -EOPNOTSUPP;
>> + goto out;
>> + }
>>
>> err = vsock_auto_bind(vsk);
>> if (err)
>> @@ -1643,7 +1651,7 @@ 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 +1674,34 @@ static int vsock_connectible_setsockopt(struct socket *sock,
>>
>> transport = vsk->transport;
>>
>> + if (level == SOL_SOCKET) {
>> + int zerocopy;
>> +
>> + if (optname != SO_ZEROCOPY) {
>> + release_sock(sk);
>> + return sock_setsockopt(sock, level, optname, optval, optlen);
>> + }
>> +
>> + /* Use 'int' type here, because variable to
>> + * set this option usually has this type.
>> + */
>> + COPY_IN(zerocopy);
>> +
>> + if (zerocopy < 0 || zerocopy > 1) {
>> + err = -EINVAL;
>> + goto exit;
>> + }
>> +
>> + if (transport && !vsock_msgzerocopy_allow(transport)) {
>> + err = -EOPNOTSUPP;
>> + goto exit;
>> + }
>> +
>> + sock_valbool_flag(sk, SOCK_ZEROCOPY,
>> + zerocopy);
>
> it's not necessary to wrap this call.
Sorry, what do you mean ?
Thanks, Arseniy
>
>> + goto exit;
>> + }
>> +
>> switch (optname) {
>> case SO_VM_SOCKETS_BUFFER_SIZE:
>> COPY_IN(val);
>> @@ -2322,6 +2358,12 @@ static int vsock_create(struct net *net, struct socket *sock,
>> }
>> }
>>
>> + /* SOCK_DGRAM doesn't have 'setsockopt' callback set in its
>> + * proto_ops, so there is no handler for custom logic.
>> + */
>> + if (sock_type_connectible(sock->type))
>> + set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
>> +
>> vsock_insert_unbound(vsk);
>>
>> return 0;
>> --
>> 2.25.1
>>
>
