diff mbox series

[net-next,v4,3/6] vhost/vsock: support MSG_EOR bit processing

Message ID 20210903061541.3187840-1-arseny.krasnov@kaspersky.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series virtio/vsock: introduce MSG_EOR flag for SEQPACKET | expand

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Context Check Description
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netdev/fixes_present success Link
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netdev/tree_selection success Clearly marked for net-next
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit fail Errors and warnings before: 0 this patch: 2
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns WARNING: line length of 93 exceeds 80 columns
netdev/build_allmodconfig_warn fail Errors and warnings before: 0 this patch: 2
netdev/header_inline success Link

Commit Message

Arseny Krasnov Sept. 3, 2021, 6:15 a.m. UTC 
'MSG_EOR' handling has similar 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 | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

Comments

Stefano Garzarella Sept. 3, 2021, 6:55 a.m. UTC | #1 
On Fri, Sep 03, 2021 at 09:15:38AM +0300, Arseny Krasnov wrote:
>'MSG_EOR' handling has similar 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 | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
>index feaf650affbe..93e8d635e18f 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;
>+		u32 flags_to_restore = 0;
>
> 		spin_lock_bh(&vsock->send_pkt_list_lock);
> 		if (list_empty(&vsock->send_pkt_list)) {
>@@ -179,15 +179,20 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
> 			 * created dynamically and are initialized with header
> 			 * of current packet(except length). But in case of
> 			 * 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.
>+			 * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
>+			 * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
>+			 * there will be sequence of packets with these
>+			 * bits set. After initialized header will be copied to
>+			 * rx buffer, these required bits will be restored.
> 			 */
> 			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
>

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
kernel test robot Sept. 3, 2021, 12:05 p.m. UTC | #2 
Hi Arseny,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Arseny-Krasnov/virtio-vsock-introduce-MSG_EOR-flag-for-SEQPACKET/20210903-141720
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 29ce8f9701072fc221d9c38ad952de1a9578f95c
config: i386-randconfig-s001-20210903 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-rc1-dirty
        # https://github.com/0day-ci/linux/commit/18c4eca4204f01fb1f94bf35e760436cb537d9b3
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Arseny-Krasnov/virtio-vsock-introduce-MSG_EOR-flag-for-SEQPACKET/20210903-141720
        git checkout 18c4eca4204f01fb1f94bf35e760436cb537d9b3
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/vhost/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
>> drivers/vhost/vsock.c:192:37: sparse: sparse: restricted __le32 degrades to integer
>> drivers/vhost/vsock.c:192:37: sparse: sparse: cast to restricted __le32

vim +192 drivers/vhost/vsock.c

    89	
    90	static void
    91	vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
    92				    struct vhost_virtqueue *vq)
    93	{
    94		struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX];
    95		int pkts = 0, total_len = 0;
    96		bool added = false;
    97		bool restart_tx = false;
    98	
    99		mutex_lock(&vq->mutex);
   100	
   101		if (!vhost_vq_get_backend(vq))
   102			goto out;
   103	
   104		if (!vq_meta_prefetch(vq))
   105			goto out;
   106	
   107		/* Avoid further vmexits, we're already processing the virtqueue */
   108		vhost_disable_notify(&vsock->dev, vq);
   109	
   110		do {
   111			struct virtio_vsock_pkt *pkt;
   112			struct iov_iter iov_iter;
   113			unsigned out, in;
   114			size_t nbytes;
   115			size_t iov_len, payload_len;
   116			int head;
   117			u32 flags_to_restore = 0;
   118	
   119			spin_lock_bh(&vsock->send_pkt_list_lock);
   120			if (list_empty(&vsock->send_pkt_list)) {
   121				spin_unlock_bh(&vsock->send_pkt_list_lock);
   122				vhost_enable_notify(&vsock->dev, vq);
   123				break;
   124			}
   125	
   126			pkt = list_first_entry(&vsock->send_pkt_list,
   127					       struct virtio_vsock_pkt, list);
   128			list_del_init(&pkt->list);
   129			spin_unlock_bh(&vsock->send_pkt_list_lock);
   130	
   131			head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov),
   132						 &out, &in, NULL, NULL);
   133			if (head < 0) {
   134				spin_lock_bh(&vsock->send_pkt_list_lock);
   135				list_add(&pkt->list, &vsock->send_pkt_list);
   136				spin_unlock_bh(&vsock->send_pkt_list_lock);
   137				break;
   138			}
   139	
   140			if (head == vq->num) {
   141				spin_lock_bh(&vsock->send_pkt_list_lock);
   142				list_add(&pkt->list, &vsock->send_pkt_list);
   143				spin_unlock_bh(&vsock->send_pkt_list_lock);
   144	
   145				/* We cannot finish yet if more buffers snuck in while
   146				 * re-enabling notify.
   147				 */
   148				if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
   149					vhost_disable_notify(&vsock->dev, vq);
   150					continue;
   151				}
   152				break;
   153			}
   154	
   155			if (out) {
   156				virtio_transport_free_pkt(pkt);
   157				vq_err(vq, "Expected 0 output buffers, got %u\n", out);
   158				break;
   159			}
   160	
   161			iov_len = iov_length(&vq->iov[out], in);
   162			if (iov_len < sizeof(pkt->hdr)) {
   163				virtio_transport_free_pkt(pkt);
   164				vq_err(vq, "Buffer len [%zu] too small\n", iov_len);
   165				break;
   166			}
   167	
   168			iov_iter_init(&iov_iter, READ, &vq->iov[out], in, iov_len);
   169			payload_len = pkt->len - pkt->off;
   170	
   171			/* If the packet is greater than the space available in the
   172			 * buffer, we split it using multiple buffers.
   173			 */
   174			if (payload_len > iov_len - sizeof(pkt->hdr)) {
   175				payload_len = iov_len - sizeof(pkt->hdr);
   176	
   177				/* As we are copying pieces of large packet's buffer to
   178				 * small rx buffers, headers of packets in rx queue are
   179				 * created dynamically and are initialized with header
   180				 * of current packet(except length). But in case of
   181				 * SOCK_SEQPACKET, we also must clear message delimeter
   182				 * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
   183				 * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
   184				 * there will be sequence of packets with these
   185				 * bits set. After initialized header will be copied to
   186				 * rx buffer, these required bits will be restored.
   187				 */
   188				if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SEQ_EOM) {
   189					pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
   190					flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM;
   191	
 > 192					if (le32_to_cpu(pkt->hdr.flags & VIRTIO_VSOCK_SEQ_EOR)) {
   193						pkt->hdr.flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
   194						flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR;
   195					}
   196				}
   197			}
   198	
   199			/* Set the correct length in the header */
   200			pkt->hdr.len = cpu_to_le32(payload_len);
   201	
   202			nbytes = copy_to_iter(&pkt->hdr, sizeof(pkt->hdr), &iov_iter);
   203			if (nbytes != sizeof(pkt->hdr)) {
   204				virtio_transport_free_pkt(pkt);
   205				vq_err(vq, "Faulted on copying pkt hdr\n");
   206				break;
   207			}
   208	
   209			nbytes = copy_to_iter(pkt->buf + pkt->off, payload_len,
   210					      &iov_iter);
   211			if (nbytes != payload_len) {
   212				virtio_transport_free_pkt(pkt);
   213				vq_err(vq, "Faulted on copying pkt buf\n");
   214				break;
   215			}
   216	
   217			/* Deliver to monitoring devices all packets that we
   218			 * will transmit.
   219			 */
   220			virtio_transport_deliver_tap_pkt(pkt);
   221	
   222			vhost_add_used(vq, head, sizeof(pkt->hdr) + payload_len);
   223			added = true;
   224	
   225			pkt->off += payload_len;
   226			total_len += payload_len;
   227	
   228			/* If we didn't send all the payload we can requeue the packet
   229			 * to send it with the next available buffer.
   230			 */
   231			if (pkt->off < pkt->len) {
   232				pkt->hdr.flags |= cpu_to_le32(flags_to_restore);
   233	
   234				/* We are queueing the same virtio_vsock_pkt to handle
   235				 * the remaining bytes, and we want to deliver it
   236				 * to monitoring devices in the next iteration.
   237				 */
   238				pkt->tap_delivered = false;
   239	
   240				spin_lock_bh(&vsock->send_pkt_list_lock);
   241				list_add(&pkt->list, &vsock->send_pkt_list);
   242				spin_unlock_bh(&vsock->send_pkt_list_lock);
   243			} else {
   244				if (pkt->reply) {
   245					int val;
   246	
   247					val = atomic_dec_return(&vsock->queued_replies);
   248	
   249					/* Do we have resources to resume tx
   250					 * processing?
   251					 */
   252					if (val + 1 == tx_vq->num)
   253						restart_tx = true;
   254				}
   255	
   256				virtio_transport_free_pkt(pkt);
   257			}
   258		} while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len)));
   259		if (added)
   260			vhost_signal(&vsock->dev, vq);
   261	
   262	out:
   263		mutex_unlock(&vq->mutex);
   264	
   265		if (restart_tx)
   266			vhost_poll_queue(&tx_vq->poll);
   267	}
   268	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Stefano Garzarella Sept. 3, 2021, 12:14 p.m. UTC | #3 
On Fri, Sep 03, 2021 at 08:55:39AM +0200, Stefano Garzarella wrote:
>On Fri, Sep 03, 2021 at 09:15:38AM +0300, Arseny Krasnov wrote:
>>'MSG_EOR' handling has similar 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 | 22 +++++++++++++---------
>>1 file changed, 13 insertions(+), 9 deletions(-)
>>
>>diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
>>index feaf650affbe..93e8d635e18f 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;
>>+		u32 flags_to_restore = 0;
>>
>>		spin_lock_bh(&vsock->send_pkt_list_lock);
>>		if (list_empty(&vsock->send_pkt_list)) {
>>@@ -179,15 +179,20 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
>>			 * created dynamically and are initialized with header
>>			 * of current packet(except length). But in case of
>>			 * 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.
>>+			 * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
>>+			 * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
>>+			 * there will be sequence of packets with these
>>+			 * bits set. After initialized header will be copied to
>>+			 * rx buffer, these required bits will be restored.
>>			 */
>>			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)) {
                                                               ^
Ooops, le32_to_cpu() should close before bitwise and operator.
I missed this, but kernel test robot discovered :-)

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

NACK

Please resend fixing the issue.

Stefano
Arseny Krasnov Sept. 3, 2021, 12:34 p.m. UTC | #4 
On 03.09.2021 15:14, Stefano Garzarella wrote:
> On Fri, Sep 03, 2021 at 08:55:39AM +0200, Stefano Garzarella wrote:
>> On Fri, Sep 03, 2021 at 09:15:38AM +0300, Arseny Krasnov wrote:
>>> 'MSG_EOR' handling has similar 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 | 22 +++++++++++++---------
>>> 1 file changed, 13 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
>>> index feaf650affbe..93e8d635e18f 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;
>>> +		u32 flags_to_restore = 0;
>>>
>>> 		spin_lock_bh(&vsock->send_pkt_list_lock);
>>> 		if (list_empty(&vsock->send_pkt_list)) {
>>> @@ -179,15 +179,20 @@ vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
>>> 			 * created dynamically and are initialized with header
>>> 			 * of current packet(except length). But in case of
>>> 			 * 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.
>>> +			 * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
>>> +			 * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
>>> +			 * there will be sequence of packets with these
>>> +			 * bits set. After initialized header will be copied to
>>> +			 * rx buffer, these required bits will be restored.
>>> 			 */
>>> 			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)) {
>                                                                ^
> Ooops, le32_to_cpu() should close before bitwise and operator.
> I missed this, but kernel test robot discovered :-)
Sorry ><
>
>>> +					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
>>>
>> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
> NACK
>
> Please resend fixing the issue.
Done, v5 is sent
>
> Stefano
>
>
diff mbox series

Patch

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index feaf650affbe..93e8d635e18f 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;
+		u32 flags_to_restore = 0;
 
 		spin_lock_bh(&vsock->send_pkt_list_lock);
 		if (list_empty(&vsock->send_pkt_list)) {
@@ -179,15 +179,20 @@  vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
 			 * created dynamically and are initialized with header
 			 * of current packet(except length). But in case of
 			 * 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.
+			 * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit
+			 * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise,
+			 * there will be sequence of packets with these
+			 * bits set. After initialized header will be copied to
+			 * rx buffer, these required bits will be restored.
 			 */
 			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