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

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

[Stefano Garzarella]

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@kaspersky.com>
>---
> 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

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Re: [RFC PATCH v2 2/5] vhost/vsock: support MSG_EOR bit processing

[Stefano Garzarella]

On Tue, Aug 10, 2021 at 02:40:15PM +0300, Arseny Krasnov wrote:
>It works in the same way as 'end-of-message' bit: if packet has
>'EOM' bit, also check for 'EOR' bit.

Please describe all changes, e.g. the new variable to accumulate flags 
to restore.

>
>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..06fc132b13c8 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 |= le32_to_cpu(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 |= le32_to_cpu(VIRTIO_VSOCK_SEQ_EOR);
                                                             ^
I'm not sure this is needed, VIRTIO_VSOCK_SEQ_EOR is represented in the 
cpu endianess.

I think here you can simpy do `flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR` 
then use `pkt->hdr.flags |= cpu_to_le32(flags_to_restore);` as you 
already do.

>+				}
> 			}
> 		}
>
>@@ -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
>

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Re: [RFC PATCH v2 3/5] virito/vsock: support MSG_EOR bit processing

[Stefano Garzarella]

On Tue, Aug 10, 2021 at 02:40:32PM +0300, Arseny Krasnov wrote:
>If packet has 'EOR' bit - set MSG_EOR in 'recvmsg()' flags.
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
> net/vmw_vsock/virtio_transport_common.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
>diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>index 4d5a93beceb0..59ee1be5a6dd 100644
>--- a/net/vmw_vsock/virtio_transport_common.c
>+++ b/net/vmw_vsock/virtio_transport_common.c
>@@ -76,8 +76,12 @@ virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
> 			goto out;
>
> 		if (msg_data_left(info->msg) == 0 &&
>-		    info->type == VIRTIO_VSOCK_TYPE_SEQPACKET)
>+		    info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
> 			pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
>+
>+			if (info->msg->msg_flags & MSG_EOR)
>+				pkt->hdr.flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
>+		}
> 	}
>
> 	trace_virtio_transport_alloc_pkt(src_cid, src_port,
>@@ -460,6 +464,9 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
> 		if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
> 			msg_ready = true;
> 			vvs->msg_count--;
>+
>+			if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOR)
>+				msg->msg_flags |= MSG_EOR;
> 		}
>
> 		virtio_transport_dec_rx_pkt(vvs, pkt);
>-- 
>2.25.1
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

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Re: [RFC PATCH v2 4/5] af_vsock: rename variables in receive loop

[Stefano Garzarella]

On Tue, Aug 10, 2021 at 02:41:00PM +0300, Arseny Krasnov wrote:
>Record is supported via MSG_EOR flag, while current logic operates
>with message, so rename variables from 'record' to 'message'.
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
> net/vmw_vsock/af_vsock.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 3e02cc3b24f8..e2c0cfb334d2 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -2014,7 +2014,7 @@ static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
> {
> 	const struct vsock_transport *transport;
> 	struct vsock_sock *vsk;
>-	ssize_t record_len;
>+	ssize_t msg_len;
> 	long timeout;
> 	int err = 0;
> 	DEFINE_WAIT(wait);
>@@ -2028,9 +2028,9 @@ static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
> 	if (err <= 0)
> 		goto out;
>
>-	record_len = transport->seqpacket_dequeue(vsk, msg, flags);
>+	msg_len = transport->seqpacket_dequeue(vsk, msg, flags);
>
>-	if (record_len < 0) {
>+	if (msg_len < 0) {
> 		err = -ENOMEM;
> 		goto out;
> 	}
>@@ -2044,14 +2044,14 @@ static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg,
> 		 * packet.
> 		 */
> 		if (flags & MSG_TRUNC)
>-			err = record_len;
>+			err = msg_len;
> 		else
> 			err = len - msg_data_left(msg);
>
> 		/* Always set MSG_TRUNC if real length of packet is
> 		 * bigger than user's buffer.
> 		 */
>-		if (record_len > len)
>+		if (msg_len > len)
> 			msg->msg_flags |= MSG_TRUNC;
> 	}
>
>-- 
>2.25.1
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

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Re: [RFC PATCH v2 5/5] vsock_test: update message bounds test for MSG_EOR

[Stefano Garzarella]

On Tue, Aug 10, 2021 at 02:41:16PM +0300, Arseny Krasnov wrote:
>Set 'MSG_EOR' in one of message sent, check that 'MSG_EOR'
>is visible in corresponding message at receiver.
>
>Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
>---
> tools/testing/vsock/vsock_test.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
>diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c
>index 67766bfe176f..2a3638c0a008 100644
>--- a/tools/testing/vsock/vsock_test.c
>+++ b/tools/testing/vsock/vsock_test.c
>@@ -282,6 +282,7 @@ static void test_stream_msg_peek_server(const struct test_opts *opts)
> }
>
> #define MESSAGES_CNT 7
>+#define MSG_EOR_IDX (MESSAGES_CNT / 2)
> static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
> {
> 	int fd;
>@@ -294,7 +295,7 @@ static void test_seqpacket_msg_bounds_client(const struct test_opts *opts)
>
> 	/* Send several messages, one with MSG_EOR flag */
> 	for (int i = 0; i < MESSAGES_CNT; i++)
>-		send_byte(fd, 1, 0);
>+		send_byte(fd, 1, (i == MSG_EOR_IDX) ? MSG_EOR : 0);
>
> 	control_writeln("SENDDONE");
> 	close(fd);
>@@ -324,6 +325,11 @@ static void test_seqpacket_msg_bounds_server(const struct test_opts *opts)
> 			perror("message bound violated");
> 			exit(EXIT_FAILURE);
> 		}
>+
>+		if ((i == MSG_EOR_IDX) ^ !!(msg.msg_flags & MSG_EOR)) {
>+			perror("MSG_EOR");
>+			exit(EXIT_FAILURE);
>+		}
> 	}
>
> 	close(fd);
>-- 
>2.25.1
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

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