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. > > >> 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 >
