On Sun, Sep 05, 2021 at 07:02:44PM +0300, Arseny Krasnov wrote: > > On 05.09.2021 18:55, Michael S. Tsirkin wrote: > > On Fri, Sep 03, 2021 at 03:30:13PM +0300, Arseny Krasnov wrote: > >> This patchset implements support of MSG_EOR bit for SEQPACKET > >> AF_VSOCK sockets over virtio transport. > >> First we need to define 'messages' and 'records' like this: > >> Message is result of sending calls: 'write()', 'send()', 'sendmsg()' > >> etc. It has fixed maximum length, and it bounds are visible using > >> return from receive calls: 'read()', 'recv()', 'recvmsg()' etc. > >> Current implementation based on message definition above. > >> Record has unlimited length, it consists of multiple message, > >> and bounds of record are visible via MSG_EOR flag returned from > >> 'recvmsg()' call. Sender passes MSG_EOR to sending system call and > >> receiver will see MSG_EOR when corresponding message will be processed. > >> Idea of patchset comes from POSIX: it says that SEQPACKET > >> supports record boundaries which are visible for receiver using > >> MSG_EOR bit. So, it looks like MSG_EOR is enough thing for SEQPACKET > >> and we don't need to maintain boundaries of corresponding send - > >> receive system calls. But, for 'sendXXX()' and 'recXXX()' POSIX says, > >> that all these calls operates with messages, e.g. 'sendXXX()' sends > >> message, while 'recXXX()' reads messages and for SEQPACKET, 'recXXX()' > >> must read one entire message from socket, dropping all out of size > >> bytes. Thus, both message boundaries and MSG_EOR bit must be supported > >> to follow POSIX rules. > >> To support MSG_EOR new bit was added along with existing > >> 'VIRTIO_VSOCK_SEQ_EOR': 'VIRTIO_VSOCK_SEQ_EOM'(end-of-message) - now it > >> works in the same way as 'VIRTIO_VSOCK_SEQ_EOR'. But 'VIRTIO_VSOCK_SEQ_EOR' > >> is used to mark 'MSG_EOR' bit passed from userspace. > >> This patchset includes simple test for MSG_EOR. > > > > I'm prepared to merge this for this window, > > but I'm not sure who's supposed to ack the net/vmw_vsock/af_vsock.c > > bits. It's a harmless variable renaming so maybe it does not matter. > > > > The rest is virtio stuff so I guess my tree is ok. > > > > Objections, anyone? > > https://lkml.org/lkml/2021/9/3/76 this is v4. It is same as v5 in af_vsock.c changes. > > It has Reviewed by from Stefano Garzarella. Is Stefano the maintainer for af_vsock then? I wasn't sure. > > > > > >> Arseny Krasnov(6): > >> virtio/vsock: rename 'EOR' to 'EOM' bit. > >> virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOR' bit. > >> vhost/vsock: support MSG_EOR bit processing > >> virtio/vsock: support MSG_EOR bit processing > >> af_vsock: rename variables in receive loop > >> vsock_test: update message bounds test for MSG_EOR > >> > >> drivers/vhost/vsock.c | 28 +++++++++++++---------- > >> include/uapi/linux/virtio_vsock.h | 3 ++- > >> net/vmw_vsock/af_vsock.c | 10 ++++---- > >> net/vmw_vsock/virtio_transport_common.c | 23 ++++++++++++------- > >> tools/testing/vsock/vsock_test.c | 8 ++++++- > >> 5 files changed, 45 insertions(+), 27 deletions(-) > >> > >> v4 -> v5: > >> - Move bitwise and out of le32_to_cpu() in 0003. > >> > >> v3 -> v4: > >> - 'sendXXX()' renamed to 'send*()' in 0002- commit msg. > >> - Comment about bit restore updated in 0003-. > >> - 'same' renamed to 'similar' in 0003- commit msg. > >> - u32 used instead of uint32_t in 0003-. > >> > >> v2 -> v3: > >> - 'virtio/vsock: rename 'EOR' to 'EOM' bit.' - commit message updated. > >> - 'VIRTIO_VSOCK_SEQ_EOR' bit add moved to separate patch. > >> - 'vhost/vsock: support MSG_EOR bit processing' - commit message > >> updated. > >> - 'vhost/vsock: support MSG_EOR bit processing' - removed unneeded > >> 'le32_to_cpu()', because input argument was already in CPU > >> endianness. > >> > >> v1 -> v2: > >> - 'VIRTIO_VSOCK_SEQ_EOR' is renamed to 'VIRTIO_VSOCK_SEQ_EOM', to > >> support backward compatibility. > >> - use bitmask of flags to restore in vhost.c, instead of separated > >> bool variable for each flag. > >> - test for EAGAIN removed, as logically it is not part of this > >> patchset(will be sent separately). > >> - cover letter updated(added part with POSIX description). > >> > >> Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx> > >> -- > >> 2.25.1 > >
