Michael S. Tsirkin
2021-Feb-23 14:17 UTC
[RFC PATCH v5 11/19] virtio/vsock: dequeue callback for SOCK_SEQPACKET
On Thu, Feb 18, 2021 at 08:39:37AM +0300, Arseny Krasnov wrote:> This adds transport callback and it's logic for SEQPACKET dequeue. > Callback fetches RW packets from rx queue of socket until whole record > is copied(if user's buffer is full, user is not woken up). This is done > to not stall sender, because if we wake up user and it leaves syscall, > nobody will send credit update for rest of record, and sender will wait > for next enter of read syscall at receiver's side. So if user buffer is > full, we just send credit update and drop data. If during copy SEQ_BEGIN > was found(and not all data was copied), copying is restarted by reset > user's iov iterator(previous unfinished data is dropped). > > Signed-off-by: Arseny Krasnov <arseny.krasnov at kaspersky.com> > --- > include/linux/virtio_vsock.h | 10 +++ > include/uapi/linux/virtio_vsock.h | 16 ++++ > net/vmw_vsock/virtio_transport_common.c | 114 ++++++++++++++++++++++++ > 3 files changed, 140 insertions(+) > > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index dc636b727179..003d06ae4a85 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -36,6 +36,11 @@ struct virtio_vsock_sock { > u32 rx_bytes; > u32 buf_alloc; > struct list_head rx_queue; > + > + /* For SOCK_SEQPACKET */ > + u32 user_read_seq_len; > + u32 user_read_copied; > + u32 curr_rx_msg_cnt;wrap these in a struct to make it's clearer they are related?> }; > > struct virtio_vsock_pkt { > @@ -80,6 +85,11 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk, > struct msghdr *msg, > size_t len, int flags); > > +int > +virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk, > + struct msghdr *msg, > + int flags, > + bool *msg_ready); > s64 virtio_transport_stream_has_data(struct vsock_sock *vsk); > s64 virtio_transport_stream_has_space(struct vsock_sock *vsk); > > diff --git a/include/uapi/linux/virtio_vsock.h b/include/uapi/linux/virtio_vsock.h > index 1d57ed3d84d2..cf9c165e5cca 100644 > --- a/include/uapi/linux/virtio_vsock.h > +++ b/include/uapi/linux/virtio_vsock.h > @@ -63,8 +63,14 @@ struct virtio_vsock_hdr { > __le32 fwd_cnt; > } __attribute__((packed)); > > +struct virtio_vsock_seq_hdr { > + __le32 msg_cnt; > + __le32 msg_len; > +} __attribute__((packed)); > + > enum virtio_vsock_type { > VIRTIO_VSOCK_TYPE_STREAM = 1, > + VIRTIO_VSOCK_TYPE_SEQPACKET = 2, > }; > > enum virtio_vsock_op { > @@ -83,6 +89,11 @@ enum virtio_vsock_op { > VIRTIO_VSOCK_OP_CREDIT_UPDATE = 6, > /* Request the peer to send the credit info to us */ > VIRTIO_VSOCK_OP_CREDIT_REQUEST = 7, > + > + /* Record begin for SOCK_SEQPACKET */ > + VIRTIO_VSOCK_OP_SEQ_BEGIN = 8, > + /* Record end for SOCK_SEQPACKET */ > + VIRTIO_VSOCK_OP_SEQ_END = 9, > }; > > /* VIRTIO_VSOCK_OP_SHUTDOWN flags values */ > @@ -91,4 +102,9 @@ enum virtio_vsock_shutdown { > VIRTIO_VSOCK_SHUTDOWN_SEND = 2, > }; > > +/* VIRTIO_VSOCK_OP_RW flags values */ > +enum virtio_vsock_rw { > + VIRTIO_VSOCK_RW_EOR = 1, > +}; > + > #endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */Probably a good idea to also have a feature bit gating this functionality. -- MST