Re: [RFC PATCH v2 1/5] virtio/vsock: add 'VIRTIO_VSOCK_SEQ_EOM' bit

From: Stefano Garzarella
Date: Wed Aug 11 2021 - 05:00:48 EST


On Tue, Aug 10, 2021 at 02:39:53PM +0300, Arseny Krasnov wrote:

The title is confusing, we are renaming EOR in EOM.

This bit is used to mark end of messages('EOM' - end of message), while
'VIRIO_VSOCK_SEQ_EOR' is used to pass MSG_EOR. Also rename 'record' to
'message' in implementation as it is different things.

Signed-off-by: Arseny Krasnov <arseny.krasnov@xxxxxxxxxxxxx>
---
drivers/vhost/vsock.c | 12 ++++++------
include/uapi/linux/virtio_vsock.h | 3 ++-
net/vmw_vsock/virtio_transport_common.c | 14 +++++++-------
3 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index f249622ef11b..feaf650affbe 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -178,15 +178,15 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
* small rx buffers, headers of packets in rx queue are
* created dynamically and are initialized with header
* of current packet(except length). But in case of
- * SOCK_SEQPACKET, we also must clear record delimeter
- * bit(VIRTIO_VSOCK_SEQ_EOR). Otherwise, instead of one
- * packet with delimeter(which marks end of record),
+ * SOCK_SEQPACKET, we also must clear message delimeter
+ * bit(VIRTIO_VSOCK_SEQ_EOM). Otherwise, instead of one
+ * packet with delimeter(which marks end of message),
* there will be sequence of packets with delimeter
* bit set. After initialized header will be copied to
* rx buffer, this bit will be restored.
*/
- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) {
- pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
+ pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
restore_flag = true;
}
}
@@ -225,7 +225,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
*/
if (pkt->off < pkt->len) {
if (restore_flag)
- pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+ pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);

/* We are queueing the same virtio_vsock_pkt to handle
* the remaining bytes, and we want to deliver it
diff --git a/include/uapi/linux/virtio_vsock.h b/include/uapi/linux/virtio_vsock.h
index 3dd3555b2740..64738838bee5 100644
--- a/include/uapi/linux/virtio_vsock.h
+++ b/include/uapi/linux/virtio_vsock.h
@@ -97,7 +97,8 @@ enum virtio_vsock_shutdown {

/* VIRTIO_VSOCK_OP_RW flags values */
enum virtio_vsock_rw {
- VIRTIO_VSOCK_SEQ_EOR = 1,
+ VIRTIO_VSOCK_SEQ_EOM = 1,
+ VIRTIO_VSOCK_SEQ_EOR = 2,
^
I think is better to add this new flag in a separate patch.

};

#endif /* _UAPI_LINUX_VIRTIO_VSOCK_H */
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 081e7ae93cb1..4d5a93beceb0 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -77,7 +77,7 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,

if (msg_data_left(info->msg) == 0 &&
info->type == VIRTIO_VSOCK_TYPE_SEQPACKET)
- pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+ pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
}

trace_virtio_transport_alloc_pkt(src_cid, src_port,
@@ -457,7 +457,7 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
dequeued_len += pkt_len;
}

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) {
+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
msg_ready = true;
vvs->msg_count--;
}
@@ -1029,7 +1029,7 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
goto out;
}

- if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
+ if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)
vvs->msg_count++;

/* Try to copy small packets into the buffer of last packet queued,
@@ -1044,12 +1044,12 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,

/* If there is space in the last packet queued, we copy the
* new packet in its buffer. We avoid this if the last packet
- * queued has VIRTIO_VSOCK_SEQ_EOR set, because this is
- * delimiter of SEQPACKET record, so 'pkt' is the first packet
- * of a new record.
+ * queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
+ * delimiter of SEQPACKET message, so 'pkt' is the first packet
+ * of a new message.
*/
if ((pkt->len <= last_pkt->buf_len - last_pkt->len) &&
- !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)) {
+ !(le32_to_cpu(last_pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM)) {
memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
pkt->len);
last_pkt->len += pkt->len;
--
2.25.1


The rest LGTM!

Thanks,
Stefano