On 05.09.2021 19:19, Michael S. Tsirkin wrote: > 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. Ack, let's wait for maintainer's comment > >>> >>>> 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 >
