[RFC PATCH v3 3/6] vhost/vsock: support MSG_EOR bit processing

[Arseny Krasnov <arseny.krasnov@kaspersky.com>]

'MSG_EOR' handling has same logic as 'MSG_EOM' - if bit present
in packet's header, reset it to 0. Then restore it back if packet
processing wasn't completed. Instead of bool variable for each
flag, bit mask variable was added: it has logical OR of 'MSG_EOR'
and 'MSG_EOM' if needed, to restore flags, this variable is ORed
with flags field of packet.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
---
 drivers/vhost/vsock.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index feaf650affbe..d217955bbcd4 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -114,7 +114,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 		size_t nbytes;
 		size_t iov_len, payload_len;
 		int head;
-		bool restore_flag = false;
+		uint32_t flags_to_restore = 0;
 
 		spin_lock_bh(&vsock->send_pkt_list_lock);
 		if (list_empty(&vsock->send_pkt_list)) {
@@ -187,7 +187,12 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 			 */
 			if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
 				pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
-				restore_flag = true;
+				flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM;
+
+				if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR) {
+					pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
+					flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR;
+				}
 			}
 		}
 
@@ -224,8 +229,7 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 		 * to send it with the next available buffer.
 		 */
 		if (pkt->off < pkt->len) {
-			if (restore_flag)
-				pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
+			pkt->hdr.flags |= cpu_to_le32(flags_to_restore);
 
 			/* We are queueing the same virtio_vsock_pkt to handle
 			 * the remaining bytes, and we want to deliver it
-- 
2.25.1