Re: [PATCH net-next v3 4/4] vsock/virtio: MSG_ZEROCOPY flag support
From: Arseniy Krasnov
Date: Tue Jul 25 2023 - 09:40:56 EST
On 25.07.2023 16:36, Michael S. Tsirkin wrote:
> On Tue, Jul 25, 2023 at 04:28:14PM +0300, Arseniy Krasnov wrote:
>>
>>
>> On 25.07.2023 16:22, Michael S. Tsirkin wrote:
>>> On Tue, Jul 25, 2023 at 04:04:13PM +0300, Arseniy Krasnov wrote:
>>>>
>>>>
>>>> On 25.07.2023 14:50, Michael S. Tsirkin wrote:
>>>>> On Fri, Jul 21, 2023 at 08:09:03AM +0300, Arseniy Krasnov wrote:
>>>>>>
>>>>>>
>>>>>> On 21.07.2023 00:42, Arseniy Krasnov wrote:
>>>>>>> This adds handling of MSG_ZEROCOPY flag on transmission path: if this
>>>>>>> flag is set and zerocopy transmission is possible (enabled in socket
>>>>>>> options and transport allows zerocopy), then non-linear skb will be
>>>>>>> created and filled with the pages of user's buffer. Pages of user's
>>>>>>> buffer are locked in memory by 'get_user_pages()'. Second thing that
>>>>>>> this patch does is replace type of skb owning: instead of calling
>>>>>>> 'skb_set_owner_sk_safe()' it calls 'skb_set_owner_w()'. Reason of this
>>>>>>> change is that '__zerocopy_sg_from_iter()' increments 'sk_wmem_alloc'
>>>>>>> of socket, so to decrease this field correctly proper skb destructor is
>>>>>>> needed: 'sock_wfree()'. This destructor is set by 'skb_set_owner_w()'.
>>>>>>>
>>>>>>> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
>>>>>>> ---
>>>>>>> Changelog:
>>>>>>> v5(big patchset) -> v1:
>>>>>>> * Refactorings of 'if' conditions.
>>>>>>> * Remove extra blank line.
>>>>>>> * Remove 'frag_off' field unneeded init.
>>>>>>> * Add function 'virtio_transport_fill_skb()' which fills both linear
>>>>>>> and non-linear skb with provided data.
>>>>>>> v1 -> v2:
>>>>>>> * Use original order of last four arguments in 'virtio_transport_alloc_skb()'.
>>>>>>> v2 -> v3:
>>>>>>> * Add new transport callback: 'msgzerocopy_check_iov'. It checks that
>>>>>>> provided 'iov_iter' with data could be sent in a zerocopy mode.
>>>>>>> If this callback is not set in transport - transport allows to send
>>>>>>> any 'iov_iter' in zerocopy mode. Otherwise - if callback returns 'true'
>>>>>>> then zerocopy is allowed. Reason of this callback is that in case of
>>>>>>> G2H transmission we insert whole skb to the tx virtio queue and such
>>>>>>> skb must fit to the size of the virtio queue to be sent in a single
>>>>>>> iteration (may be tx logic in 'virtio_transport.c' could be reworked
>>>>>>> as in vhost to support partial send of current skb). This callback
>>>>>>> will be enabled only for G2H path. For details pls see comment
>>>>>>> 'Check that tx queue...' below.
>>>>>>>
>>>>>>> include/net/af_vsock.h | 3 +
>>>>>>> net/vmw_vsock/virtio_transport.c | 39 ++++
>>>>>>> net/vmw_vsock/virtio_transport_common.c | 257 ++++++++++++++++++------
>>>>>>> 3 files changed, 241 insertions(+), 58 deletions(-)
>>>>>>>
>>>>>>> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
>>>>>>> index 0e7504a42925..a6b346eeeb8e 100644
>>>>>>> --- a/include/net/af_vsock.h
>>>>>>> +++ b/include/net/af_vsock.h
>>>>>>> @@ -177,6 +177,9 @@ struct vsock_transport {
>>>>>>>
>>>>>>> /* Read a single skb */
>>>>>>> int (*read_skb)(struct vsock_sock *, skb_read_actor_t);
>>>>>>> +
>>>>>>> + /* Zero-copy. */
>>>>>>> + bool (*msgzerocopy_check_iov)(const struct iov_iter *);
>>>>>>> };
>>>>>>>
>>>>>>> /**** CORE ****/
>>>>>>> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
>>>>>>> index 7bbcc8093e51..23cb8ed638c4 100644
>>>>>>> --- a/net/vmw_vsock/virtio_transport.c
>>>>>>> +++ b/net/vmw_vsock/virtio_transport.c
>>>>>>> @@ -442,6 +442,43 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)
>>>>>>> queue_work(virtio_vsock_workqueue, &vsock->rx_work);
>>>>>>> }
>>>>>>>
>>>>>>> +static bool virtio_transport_msgzerocopy_check_iov(const struct iov_iter *iov)
>>>>>>> +{
>>>>>>> + struct virtio_vsock *vsock;
>>>>>>> + bool res = false;
>>>>>>> +
>>>>>>> + rcu_read_lock();
>>>>>>> +
>>>>>>> + vsock = rcu_dereference(the_virtio_vsock);
>>>>>>> + if (vsock) {
>>>>>>> + struct virtqueue *vq;
>>>>>>> + int iov_pages;
>>>>>>> +
>>>>>>> + vq = vsock->vqs[VSOCK_VQ_TX];
>>>>>>> +
>>>>>>> + iov_pages = round_up(iov->count, PAGE_SIZE) / PAGE_SIZE;
>>>>>>> +
>>>>>>> + /* Check that tx queue is large enough to keep whole
>>>>>>> + * data to send. This is needed, because when there is
>>>>>>> + * not enough free space in the queue, current skb to
>>>>>>> + * send will be reinserted to the head of tx list of
>>>>>>> + * the socket to retry transmission later, so if skb
>>>>>>> + * is bigger than whole queue, it will be reinserted
>>>>>>> + * again and again, thus blocking other skbs to be sent.
>>>>>>> + * Each page of the user provided buffer will be added
>>>>>>> + * as a single buffer to the tx virtqueue, so compare
>>>>>>> + * number of pages against maximum capacity of the queue.
>>>>>>> + * +1 means buffer for the packet header.
>>>>>>> + */
>>>>>>> + if (iov_pages + 1 <= vq->num_max)
>>>>>>
>>>>>> I think this check is actual only for case one we don't have indirect buffer feature.
>>>>>> With indirect mode whole data to send will be packed into one indirect buffer.
>>>>>>
>>>>>> Thanks, Arseniy
>>>>>
>>>>> Actually the reverse. With indirect you are limited to num_max.
>>>>> Without you are limited to whatever space is left in the
>>>>> queue (which you did not check here, so you should).
>>>>
>>>> I mean that with indirect, we only need one buffer, and we can just wait
>>>> for enough space - for this single buffer ( as we discussed a little bit before).
>>>> But if indirect buffer is not supported - we need that whole packet must fit
>>>> to the size of tx queue - otherwise it never be transmitted.
>>>>
>>>> Thanks, Arseniy
>>>
>>>
>>> yes but according to virtio spec it's illegal to add s/g that is bigger
>>> than queue size.
>>
>> Aah, so even in case of indirect buffers feature, buffer descriptors stored in memory
>> pointed by indirect buffer must be accounted against queue size ?
>>
>> Thanks, Arseniy
>
> a single indirect buffer can't exceed vq size.
I see, so i guess right way is to compare length of data "in buffers"
again 'num_max', as it is implemented. And we should not refer to whether
vq support indirect buffering or not.
Thanks, Arseniy
>
>
>>>
>>>>>
>>>>>
>>>>>>> + res = true;
>>>>>>> + }
>>>>>>> +
>>>>>>> + rcu_read_unlock();
>>>>>
>>>>> Just curious:
>>>>> is the point of all this RCU dance to allow vsock
>>>>> to change from under us? then why is it ok to
>>>>> have it change? the virtio_transport_msgzerocopy_check_iov
>>>>> will then refer to the old vsock ...
>>>>>
>>>>>
>>>>>>> +
>>>>>>> + return res;
>>>>>>> +}
>>>>>>> +
>>>>>>> static bool virtio_transport_seqpacket_allow(u32 remote_cid);
>>>>>>>
>>>>>>> static struct virtio_transport virtio_transport = {
>>>>>>> @@ -475,6 +512,8 @@ static struct virtio_transport virtio_transport = {
>>>>>>> .seqpacket_allow = virtio_transport_seqpacket_allow,
>>>>>>> .seqpacket_has_data = virtio_transport_seqpacket_has_data,
>>>>>>>
>>>>>>> + .msgzerocopy_check_iov = virtio_transport_msgzerocopy_check_iov,
>>>>>>> +
>>>>>>> .notify_poll_in = virtio_transport_notify_poll_in,
>>>>>>> .notify_poll_out = virtio_transport_notify_poll_out,
>>>>>>> .notify_recv_init = virtio_transport_notify_recv_init,
>>>>>>> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
>>>>>>> index 26a4d10da205..e4e3d541aff4 100644
>>>>>>> --- a/net/vmw_vsock/virtio_transport_common.c
>>>>>>> +++ b/net/vmw_vsock/virtio_transport_common.c
>>>>>>> @@ -37,73 +37,122 @@ virtio_transport_get_ops(struct vsock_sock *vsk)
>>>>>>> return container_of(t, struct virtio_transport, transport);
>>>>>>> }
>>>>>>>
>>>>>>> -/* Returns a new packet on success, otherwise returns NULL.
>>>>>>> - *
>>>>>>> - * If NULL is returned, errp is set to a negative errno.
>>>>>>> - */
>>>>>>> -static struct sk_buff *
>>>>>>> -virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
>>>>>>> - size_t len,
>>>>>>> - u32 src_cid,
>>>>>>> - u32 src_port,
>>>>>>> - u32 dst_cid,
>>>>>>> - u32 dst_port)
>>>>>>> -{
>>>>>>> - const size_t skb_len = VIRTIO_VSOCK_SKB_HEADROOM + len;
>>>>>>> - struct virtio_vsock_hdr *hdr;
>>>>>>> - struct sk_buff *skb;
>>>>>>> - void *payload;
>>>>>>> - int err;
>>>>>>> +static bool virtio_transport_can_zcopy(struct virtio_vsock_pkt_info *info,
>>>>>>> + size_t max_to_send)
>>>>>>> +{
>>>>>>> + const struct vsock_transport *t;
>>>>>>> + struct iov_iter *iov_iter;
>>>>>>>
>>>>>>> - skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
>>>>>>> - if (!skb)
>>>>>>> - return NULL;
>>>>>>> + if (!info->msg)
>>>>>>> + return false;
>>>>>>>
>>>>>>> - hdr = virtio_vsock_hdr(skb);
>>>>>>> - hdr->type = cpu_to_le16(info->type);
>>>>>>> - hdr->op = cpu_to_le16(info->op);
>>>>>>> - hdr->src_cid = cpu_to_le64(src_cid);
>>>>>>> - hdr->dst_cid = cpu_to_le64(dst_cid);
>>>>>>> - hdr->src_port = cpu_to_le32(src_port);
>>>>>>> - hdr->dst_port = cpu_to_le32(dst_port);
>>>>>>> - hdr->flags = cpu_to_le32(info->flags);
>>>>>>> - hdr->len = cpu_to_le32(len);
>>>>>>> + iov_iter = &info->msg->msg_iter;
>>>>>>>
>>>>>>> - if (info->msg && len > 0) {
>>>>>>> - payload = skb_put(skb, len);
>>>>>>> - err = memcpy_from_msg(payload, info->msg, len);
>>>>>>> - if (err)
>>>>>>> - goto out;
>>>>>>> + t = vsock_core_get_transport(info->vsk);
>>>>>>>
>>>>>>> - if (msg_data_left(info->msg) == 0 &&
>>>>>>> - info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
>>>>>>> - hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
>>>>>>> + if (t->msgzerocopy_check_iov &&
>>>>>>> + !t->msgzerocopy_check_iov(iov_iter))
>>>>>>> + return false;
>>>>>>>
>>>>>>> - if (info->msg->msg_flags & MSG_EOR)
>>>>>>> - hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
>>>>>>> - }
>>>>>>> + /* Data is simple buffer. */
>>>>>>> + if (iter_is_ubuf(iov_iter))
>>>>>>> + return true;
>>>>>>> +
>>>>>>> + if (!iter_is_iovec(iov_iter))
>>>>>>> + return false;
>>>>>>> +
>>>>>>> + if (iov_iter->iov_offset)
>>>>>>> + return false;
>>>>>>> +
>>>>>>> + /* We can't send whole iov. */
>>>>>>> + if (iov_iter->count > max_to_send)
>>>>>>> + return false;
>>>>>>> +
>>>>>>> + return true;
>>>>>>> +}
>>>>>>> +
>>>>>>> +static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk,
>>>>>>> + struct sk_buff *skb,
>>>>>>> + struct msghdr *msg,
>>>>>>> + bool zerocopy)
>>>>>>> +{
>>>>>>> + struct ubuf_info *uarg;
>>>>>>> +
>>>>>>> + if (msg->msg_ubuf) {
>>>>>>> + uarg = msg->msg_ubuf;
>>>>>>> + net_zcopy_get(uarg);
>>>>>>> + } else {
>>>>>>> + struct iov_iter *iter = &msg->msg_iter;
>>>>>>> + struct ubuf_info_msgzc *uarg_zc;
>>>>>>> + int len;
>>>>>>> +
>>>>>>> + /* Only ITER_IOVEC or ITER_UBUF are allowed and
>>>>>>> + * checked before.
>>>>>>> + */
>>>>>>> + if (iter_is_iovec(iter))
>>>>>>> + len = iov_length(iter->__iov, iter->nr_segs);
>>>>>>> + else
>>>>>>> + len = iter->count;
>>>>>>> +
>>>>>>> + uarg = msg_zerocopy_realloc(sk_vsock(vsk),
>>>>>>> + len,
>>>>>>> + NULL);
>>>>>>> + if (!uarg)
>>>>>>> + return -1;
>>>>>>> +
>>>>>>> + uarg_zc = uarg_to_msgzc(uarg);
>>>>>>> + uarg_zc->zerocopy = zerocopy ? 1 : 0;
>>>>>>> }
>>>>>>>
>>>>>>> - if (info->reply)
>>>>>>> - virtio_vsock_skb_set_reply(skb);
>>>>>>> + skb_zcopy_init(skb, uarg);
>>>>>>>
>>>>>>> - trace_virtio_transport_alloc_pkt(src_cid, src_port,
>>>>>>> - dst_cid, dst_port,
>>>>>>> - len,
>>>>>>> - info->type,
>>>>>>> - info->op,
>>>>>>> - info->flags);
>>>>>>> + return 0;
>>>>>>> +}
>>>>>>>
>>>>>>> - if (info->vsk && !skb_set_owner_sk_safe(skb, sk_vsock(info->vsk))) {
>>>>>>> - WARN_ONCE(1, "failed to allocate skb on vsock socket with sk_refcnt == 0\n");
>>>>>>> - goto out;
>>>>>>> +static int virtio_transport_fill_skb(struct sk_buff *skb,
>>>>>>> + struct virtio_vsock_pkt_info *info,
>>>>>>> + size_t len,
>>>>>>> + bool zcopy)
>>>>>>> +{
>>>>>>> + if (zcopy) {
>>>>>>> + return __zerocopy_sg_from_iter(info->msg, NULL, skb,
>>>>>>> + &info->msg->msg_iter,
>>>>>>> + len);
>>>>>>> + } else {
>>>>>>> + void *payload;
>>>>>>> + int err;
>>>>>>> +
>>>>>>> + payload = skb_put(skb, len);
>>>>>>> + err = memcpy_from_msg(payload, info->msg, len);
>>>>>>> + if (err)
>>>>>>> + return -1;
>>>>>>> +
>>>>>>> + if (msg_data_left(info->msg))
>>>>>>> + return 0;
>>>>>>> +
>>>>>>> + return 0;
>>>>>>> }
>>>>>>> +}
>>>>>>>
>>>>>>> - return skb;
>>>>>>> +static void virtio_transport_init_hdr(struct sk_buff *skb,
>>>>>>> + struct virtio_vsock_pkt_info *info,
>>>>>>> + u32 src_cid,
>>>>>>> + u32 src_port,
>>>>>>> + u32 dst_cid,
>>>>>>> + u32 dst_port,
>>>>>>> + size_t len)
>>>>>>> +{
>>>>>>> + struct virtio_vsock_hdr *hdr;
>>>>>>>
>>>>>>> -out:
>>>>>>> - kfree_skb(skb);
>>>>>>> - return NULL;
>>>>>>> + hdr = virtio_vsock_hdr(skb);
>>>>>>> + hdr->type = cpu_to_le16(info->type);
>>>>>>> + hdr->op = cpu_to_le16(info->op);
>>>>>>> + hdr->src_cid = cpu_to_le64(src_cid);
>>>>>>> + hdr->dst_cid = cpu_to_le64(dst_cid);
>>>>>>> + hdr->src_port = cpu_to_le32(src_port);
>>>>>>> + hdr->dst_port = cpu_to_le32(dst_port);
>>>>>>> + hdr->flags = cpu_to_le32(info->flags);
>>>>>>> + hdr->len = cpu_to_le32(len);
>>>>>>> }
>>>>>>>
>>>>>>> static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
>>>>>>> @@ -214,6 +263,70 @@ static u16 virtio_transport_get_type(struct sock *sk)
>>>>>>> return VIRTIO_VSOCK_TYPE_SEQPACKET;
>>>>>>> }
>>>>>>>
>>>>>>> +static struct sk_buff *virtio_transport_alloc_skb(struct vsock_sock *vsk,
>>>>>>> + struct virtio_vsock_pkt_info *info,
>>>>>>> + size_t payload_len,
>>>>>>> + bool zcopy,
>>>>>>> + u32 src_cid,
>>>>>>> + u32 src_port,
>>>>>>> + u32 dst_cid,
>>>>>>> + u32 dst_port)
>>>>>>> +{
>>>>>>> + struct sk_buff *skb;
>>>>>>> + size_t skb_len;
>>>>>>> +
>>>>>>> + skb_len = VIRTIO_VSOCK_SKB_HEADROOM;
>>>>>>> +
>>>>>>> + if (!zcopy)
>>>>>>> + skb_len += payload_len;
>>>>>>> +
>>>>>>> + skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
>>>>>>> + if (!skb)
>>>>>>> + return NULL;
>>>>>>> +
>>>>>>> + virtio_transport_init_hdr(skb, info, src_cid, src_port,
>>>>>>> + dst_cid, dst_port,
>>>>>>> + payload_len);
>>>>>>> +
>>>>>>> + /* Set owner here, because '__zerocopy_sg_from_iter()' uses
>>>>>>> + * owner of skb without check to update 'sk_wmem_alloc'.
>>>>>>> + */
>>>>>>> + if (vsk)
>>>>>>> + skb_set_owner_w(skb, sk_vsock(vsk));
>>>>>>> +
>>>>>>> + if (info->msg && payload_len > 0) {
>>>>>>> + int err;
>>>>>>> +
>>>>>>> + err = virtio_transport_fill_skb(skb, info, payload_len, zcopy);
>>>>>>> + if (err)
>>>>>>> + goto out;
>>>>>>> +
>>>>>>> + if (info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
>>>>>>> + struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
>>>>>>> +
>>>>>>> + hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
>>>>>>> +
>>>>>>> + if (info->msg->msg_flags & MSG_EOR)
>>>>>>> + hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (info->reply)
>>>>>>> + virtio_vsock_skb_set_reply(skb);
>>>>>>> +
>>>>>>> + trace_virtio_transport_alloc_pkt(src_cid, src_port,
>>>>>>> + dst_cid, dst_port,
>>>>>>> + payload_len,
>>>>>>> + info->type,
>>>>>>> + info->op,
>>>>>>> + info->flags);
>>>>>>> +
>>>>>>> + return skb;
>>>>>>> +out:
>>>>>>> + kfree_skb(skb);
>>>>>>> + return NULL;
>>>>>>> +}
>>>>>>> +
>>>>>>> /* This function can only be used on connecting/connected sockets,
>>>>>>> * since a socket assigned to a transport is required.
>>>>>>> *
>>>>>>> @@ -222,10 +335,12 @@ static u16 virtio_transport_get_type(struct sock *sk)
>>>>>>> static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
>>>>>>> struct virtio_vsock_pkt_info *info)
>>>>>>> {
>>>>>>> + u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
>>>>>>> u32 src_cid, src_port, dst_cid, dst_port;
>>>>>>> const struct virtio_transport *t_ops;
>>>>>>> struct virtio_vsock_sock *vvs;
>>>>>>> u32 pkt_len = info->pkt_len;
>>>>>>> + bool can_zcopy = false;
>>>>>>> u32 rest_len;
>>>>>>> int ret;
>>>>>>>
>>>>>>> @@ -254,15 +369,30 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
>>>>>>> if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
>>>>>>> return pkt_len;
>>>>>>>
>>>>>>> + if (info->msg) {
>>>>>>> + /* If zerocopy is not enabled by 'setsockopt()', we behave as
>>>>>>> + * there is no MSG_ZEROCOPY flag set.
>>>>>>> + */
>>>>>>> + if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY))
>>>>>>> + info->msg->msg_flags &= ~MSG_ZEROCOPY;
>>>>>>> +
>>>>>>> + if (info->msg->msg_flags & MSG_ZEROCOPY)
>>>>>>> + can_zcopy = virtio_transport_can_zcopy(info, pkt_len);
>>>>>>> +
>>>>>>> + if (can_zcopy)
>>>>>>> + max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE,
>>>>>>> + (MAX_SKB_FRAGS * PAGE_SIZE));
>>>>>>> + }
>>>>>>> +
>>>>>>> rest_len = pkt_len;
>>>>>>>
>>>>>>> do {
>>>>>>> struct sk_buff *skb;
>>>>>>> size_t skb_len;
>>>>>>>
>>>>>>> - skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, rest_len);
>>>>>>> + skb_len = min(max_skb_len, rest_len);
>>>>>>>
>>>>>>> - skb = virtio_transport_alloc_skb(info, skb_len,
>>>>>>> + skb = virtio_transport_alloc_skb(vsk, info, skb_len, can_zcopy,
>>>>>>> src_cid, src_port,
>>>>>>> dst_cid, dst_port);
>>>>>>> if (!skb) {
>>>>>>> @@ -270,6 +400,17 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
>>>>>>> break;
>>>>>>> }
>>>>>>>
>>>>>>> + /* This is last skb to send this portion of data. */
>>>>>>> + if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY &&
>>>>>>> + skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) {
>>>>>>> + if (virtio_transport_init_zcopy_skb(vsk, skb,
>>>>>>> + info->msg,
>>>>>>> + can_zcopy)) {
>>>>>>> + ret = -ENOMEM;
>>>>>>> + break;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +
>>>>>>> virtio_transport_inc_tx_pkt(vvs, skb);
>>>>>>>
>>>>>>> ret = t_ops->send_pkt(skb);
>>>>>>> @@ -934,7 +1075,7 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
>>>>>>> if (!t)
>>>>>>> return -ENOTCONN;
>>>>>>>
>>>>>>> - reply = virtio_transport_alloc_skb(&info, 0,
>>>>>>> + reply = virtio_transport_alloc_skb(NULL, &info, 0, false,
>>>>>>> le64_to_cpu(hdr->dst_cid),
>>>>>>> le32_to_cpu(hdr->dst_port),
>>>>>>> le64_to_cpu(hdr->src_cid),
>>>>>
>>>
>