Re: [RFC v2 2/5] virtio/vsock: add support for virtio datagram

Michael S. Tsirkin
2021-09-14T06:56:45Z

On Tue, Sep 14, 2021 at 05:54:35AM +0000, Jiang Wang wrote:
> This patch add support for virtio dgram for the driver.
> Implemented related functions for tx and rx, enqueue
> and dequeue. Send packets synchronously to give sender
> indication when the virtqueue is full.

Hmm I don't see this in code.
virtio_transport_do_send_dgram_pkt just does add buf and returns.

In any case, how exactly is fairness handled?
what prevents one socket from monopolizing the device?

> Refactored virtio_transport_send_pkt_work() a little bit but
> no functions changes for it.

split the refactoring to a separate patch then pls.

>
> Support for the host/device side is in another
> patch.
>
> Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
> ---
> include/net/af_vsock.h | 1 +
> .../events/vsock_virtio_transport_common.h | 2 +
> include/uapi/linux/virtio_vsock.h | 1 +
> net/vmw_vsock/af_vsock.c | 12 +
> net/vmw_vsock/virtio_transport.c | 344 +++++++++++++++---
> net/vmw_vsock/virtio_transport_common.c | 181 ++++++++-
> 6 files changed, 467 insertions(+), 74 deletions(-)
>
> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index ab207677e0a8..58c46c694670 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -208,6 +208,7 @@ void vsock_remove_sock(struct vsock_sock *vsk);
> void vsock_for_each_connected_socket(void (*fn)(struct sock *sk));
> int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
> bool vsock_find_cid(unsigned int cid);
> +int vsock_bind_stream(struct vsock_sock *vsk, struct sockaddr_vm *addr);
>
> /**** TAP ****/
>
> diff --git a/include/trace/events/vsock_virtio_transport_common.h b/include/trace/events/vsock_virtio_transport_common.h
> index d0b3f0ea9ba1..1d8647a6b476 100644
> --- a/include/trace/events/vsock_virtio_transport_common.h
> +++ b/include/trace/events/vsock_virtio_transport_common.h
> @@ -10,10 +10,12 @@
>
> TRACE_DEFINE_ENUM(VIRTIO_VSOCK_TYPE_STREAM);
> TRACE_DEFINE_ENUM(VIRTIO_VSOCK_TYPE_SEQPACKET);
> +TRACE_DEFINE_ENUM(VIRTIO_VSOCK_TYPE_DGRAM);
>
> #define show_type(val) \
> __print_symbolic(val, \
> { VIRTIO_VSOCK_TYPE_STREAM, "STREAM" }, \
> + { VIRTIO_VSOCK_TYPE_DGRAM, "DGRAM" }, \
> { VIRTIO_VSOCK_TYPE_SEQPACKET, "SEQPACKET" })
>
> TRACE_DEFINE_ENUM(VIRTIO_VSOCK_OP_INVALID);
> diff --git a/include/uapi/linux/virtio_vsock.h b/include/uapi/linux/virtio_vsock.h
> index cff54ba9b924..3e93b75f2707 100644
> --- a/include/uapi/linux/virtio_vsock.h
> +++ b/include/uapi/linux/virtio_vsock.h
> @@ -71,6 +71,7 @@ struct virtio_vsock_hdr {
> enum virtio_vsock_type {
> VIRTIO_VSOCK_TYPE_STREAM = 1,
> VIRTIO_VSOCK_TYPE_SEQPACKET = 2,
> + VIRTIO_VSOCK_TYPE_DGRAM = 3,
> };
>
> enum virtio_vsock_op {
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 3e02cc3b24f8..adf11db32506 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -669,6 +669,18 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
> return 0;
> }
>
> +int vsock_bind_stream(struct vsock_sock *vsk,
> + struct sockaddr_vm *addr)
> +{
> + int retval;
> +
> + spin_lock_bh(&vsock_table_lock);
> + retval = __vsock_bind_connectible(vsk, addr);
> + spin_unlock_bh(&vsock_table_lock);
> + return retval;
> +}
> +EXPORT_SYMBOL(vsock_bind_stream);
> +
> static int __vsock_bind_dgram(struct vsock_sock *vsk,
> struct sockaddr_vm *addr)
> {
> diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
> index bb89f538f5f3..8d5bfcd79555 100644
> --- a/net/vmw_vsock/virtio_transport.c
> +++ b/net/vmw_vsock/virtio_transport.c
> @@ -20,21 +20,29 @@
> #include <net/sock.h>
> #include <linux/mutex.h>
> #include <net/af_vsock.h>
> +#include<linux/kobject.h>
> +#include<linux/sysfs.h>
> +#include <linux/refcount.h>
>
> static struct workqueue_struct *virtio_vsock_workqueue;
> static struct virtio_vsock __rcu *the_virtio_vsock;
> +static struct virtio_vsock *the_virtio_vsock_dgram;
> static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
>
> struct virtio_vsock {
> struct virtio_device *vdev;
> struct virtqueue **vqs;
> bool has_dgram;
> + refcount_t active;
>
> /* Virtqueue processing is deferred to a workqueue */
> struct work_struct tx_work;
> struct work_struct rx_work;
> struct work_struct event_work;
>
> + struct work_struct dgram_tx_work;
> + struct work_struct dgram_rx_work;
> +
> /* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX]
> * must be accessed with tx_lock held.
> */
> @@ -55,6 +63,22 @@ struct virtio_vsock {
> int rx_buf_nr;
> int rx_buf_max_nr;
>
> + /* The following fields are protected by dgram_tx_lock. vqs[VSOCK_VQ_DGRAM_TX]
> + * must be accessed with dgram_tx_lock held.
> + */
> + struct mutex dgram_tx_lock;
> + bool dgram_tx_run;
> +
> + atomic_t dgram_queued_replies;
> +
> + /* The following fields are protected by dgram_rx_lock. vqs[VSOCK_VQ_DGRAM_RX]
> + * must be accessed with dgram_rx_lock held.
> + */
> + struct mutex dgram_rx_lock;
> + bool dgram_rx_run;
> + int dgram_rx_buf_nr;
> + int dgram_rx_buf_max_nr;
> +
> /* The following fields are protected by event_lock.
> * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held.
> */
> @@ -84,21 +108,12 @@ static u32 virtio_transport_get_local_cid(void)
> return ret;
> }
>
> -static void
> -virtio_transport_send_pkt_work(struct work_struct *work)
> +static void virtio_transport_do_send_pkt(struct virtio_vsock *vsock,
> + struct virtqueue *vq, spinlock_t *lock,
> + struct list_head *send_pkt_list,
> + bool *restart_rx)
> {
> - struct virtio_vsock *vsock =
> - container_of(work, struct virtio_vsock, send_pkt_work);
> - struct virtqueue *vq;
> bool added = false;
> - bool restart_rx = false;
> -
> - mutex_lock(&vsock->tx_lock);
> -
> - if (!vsock->tx_run)
> - goto out;
> -
> - vq = vsock->vqs[VSOCK_VQ_TX];
>
> for (;;) {
> struct virtio_vsock_pkt *pkt;
> @@ -106,16 +121,16 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> int ret, in_sg = 0, out_sg = 0;
> bool reply;
>
> - spin_lock_bh(&vsock->send_pkt_list_lock);
> - if (list_empty(&vsock->send_pkt_list)) {
> - spin_unlock_bh(&vsock->send_pkt_list_lock);
> + spin_lock_bh(lock);
> + if (list_empty(send_pkt_list)) {
> + spin_unlock_bh(lock);
> break;
> }
>
> - pkt = list_first_entry(&vsock->send_pkt_list,
> + pkt = list_first_entry(send_pkt_list,
> struct virtio_vsock_pkt, list);
> list_del_init(&pkt->list);
> - spin_unlock_bh(&vsock->send_pkt_list_lock);
> + spin_unlock_bh(lock);
>
> virtio_transport_deliver_tap_pkt(pkt);
>
> @@ -133,9 +148,9 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> * the vq
> */
> if (ret < 0) {
> - spin_lock_bh(&vsock->send_pkt_list_lock);
> - list_add(&pkt->list, &vsock->send_pkt_list);
> - spin_unlock_bh(&vsock->send_pkt_list_lock);
> + spin_lock_bh(lock);
> + list_add(&pkt->list, send_pkt_list);
> + spin_unlock_bh(lock);
> break;
> }
>
> @@ -147,7 +162,7 @@ virtio_transport_send_pkt_work(struct work_struct *work)
>
> /* Do we now have resources to resume rx processing? */
> if (val + 1 == virtqueue_get_vring_size(rx_vq))
> - restart_rx = true;
> + *restart_rx = true;
> }
>
> added = true;
> @@ -155,7 +170,55 @@ virtio_transport_send_pkt_work(struct work_struct *work)
>
> if (added)
> virtqueue_kick(vq);
> +}
> +
> +static int virtio_transport_do_send_dgram_pkt(struct virtio_vsock *vsock,
> + struct virtqueue *vq,
> + struct virtio_vsock_pkt *pkt)
> +{
> + struct scatterlist hdr, buf, *sgs[2];
> + int ret, in_sg = 0, out_sg = 0;
> +
> + virtio_transport_deliver_tap_pkt(pkt);
> +
> + sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
> + sgs[out_sg++] = &hdr;
> + if (pkt->buf) {
> + sg_init_one(&buf, pkt->buf, pkt->len);
> + sgs[out_sg++] = &buf;
> + }
> +
> + ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt, GFP_KERNEL);
> + /* Usually this means that there is no more space available in
> + * the vq
> + */
> + if (ret < 0) {
> + virtio_transport_free_pkt(pkt);
> + return -ENOMEM;
> + }
> +
> + virtqueue_kick(vq);
> +
> + return pkt->len;
> +}
> +
> +static void
> +virtio_transport_send_pkt_work(struct work_struct *work)
> +{
> + struct virtio_vsock *vsock =
> + container_of(work, struct virtio_vsock, send_pkt_work);
> + struct virtqueue *vq;
> + bool restart_rx = false;
>
> + mutex_lock(&vsock->tx_lock);
> +
> + if (!vsock->tx_run)
> + goto out;
> +
> + vq = vsock->vqs[VSOCK_VQ_TX];
> +
> + virtio_transport_do_send_pkt(vsock, vq, &vsock->send_pkt_list_lock,
> + &vsock->send_pkt_list, &restart_rx);
> out:
> mutex_unlock(&vsock->tx_lock);
>
> @@ -163,12 +226,65 @@ virtio_transport_send_pkt_work(struct work_struct *work)
> queue_work(virtio_vsock_workqueue, &vsock->rx_work);
> }
>
> +static int
> +virtio_transport_send_dgram_pkt(struct virtio_vsock_pkt *pkt)
> +{
> + struct virtio_vsock *vsock;
> + int len = pkt->len;
> + struct virtqueue *vq;
> +
> + vsock = the_virtio_vsock_dgram;
> +
> + if (!vsock) {
> + virtio_transport_free_pkt(pkt);
> + return -ENODEV;
> + }
> +
> + if (!vsock->dgram_tx_run) {
> + virtio_transport_free_pkt(pkt);
> + return -ENODEV;
> + }
> +
> + if (!refcount_inc_not_zero(&vsock->active)) {
> + virtio_transport_free_pkt(pkt);
> + return -ENODEV;
> + }
> +
> + if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) {
> + virtio_transport_free_pkt(pkt);
> + len = -ENODEV;
> + goto out_ref;
> + }
> +
> + /* send the pkt */
> + mutex_lock(&vsock->dgram_tx_lock);
> +
> + if (!vsock->dgram_tx_run)
> + goto out_mutex;
> +
> + vq = vsock->vqs[VSOCK_VQ_DGRAM_TX];
> +
> + len = virtio_transport_do_send_dgram_pkt(vsock, vq, pkt);
> +
> +out_mutex:
> + mutex_unlock(&vsock->dgram_tx_lock);
> +
> +out_ref:
> + if (!refcount_dec_not_one(&vsock->active))
> + return -EFAULT;
> +
> + return len;
> +}
> +
> static int
> virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
> {
> struct virtio_vsock *vsock;
> int len = pkt->len;
>
> + if (pkt->hdr.type == VIRTIO_VSOCK_TYPE_DGRAM)
> + return virtio_transport_send_dgram_pkt(pkt);
> +
> rcu_read_lock();
> vsock = rcu_dereference(the_virtio_vsock);
> if (!vsock) {
> @@ -244,7 +360,7 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk)
> return ret;
> }
>
> -static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
> +static void virtio_vsock_rx_fill(struct virtio_vsock *vsock, bool is_dgram)
> {
> int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
> struct virtio_vsock_pkt *pkt;
> @@ -252,7 +368,10 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
> struct virtqueue *vq;
> int ret;
>
> - vq = vsock->vqs[VSOCK_VQ_RX];
> + if (is_dgram)
> + vq = vsock->vqs[VSOCK_VQ_DGRAM_RX];
> + else
> + vq = vsock->vqs[VSOCK_VQ_RX];
>
> do {
> pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
> @@ -278,26 +397,26 @@ static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
> virtio_transport_free_pkt(pkt);
> break;
> }
> - vsock->rx_buf_nr++;
> + if (is_dgram)
> + vsock->dgram_rx_buf_nr++;
> + else
> + vsock->rx_buf_nr++;
> } while (vq->num_free);
> - if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
> - vsock->rx_buf_max_nr = vsock->rx_buf_nr;
> + if (is_dgram) {
> + if (vsock->dgram_rx_buf_nr > vsock->dgram_rx_buf_max_nr)
> + vsock->dgram_rx_buf_max_nr = vsock->dgram_rx_buf_nr;
> + } else {
> + if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
> + vsock->rx_buf_max_nr = vsock->rx_buf_nr;
> + }
> +
> virtqueue_kick(vq);
> }
>
> -static void virtio_transport_tx_work(struct work_struct *work)
> +static bool virtio_transport_free_pkt_batch(struct virtqueue *vq)
> {
> - struct virtio_vsock *vsock =
> - container_of(work, struct virtio_vsock, tx_work);
> - struct virtqueue *vq;
> bool added = false;
>
> - vq = vsock->vqs[VSOCK_VQ_TX];
> - mutex_lock(&vsock->tx_lock);
> -
> - if (!vsock->tx_run)
> - goto out;
> -
> do {
> struct virtio_vsock_pkt *pkt;
> unsigned int len;
> @@ -309,13 +428,43 @@ static void virtio_transport_tx_work(struct work_struct *work)
> }
> } while (!virtqueue_enable_cb(vq));
>
> -out:
> + return added;
> +}
> +
> +static void virtio_transport_tx_work(struct work_struct *work)
> +{
> + struct virtio_vsock *vsock =
> + container_of(work, struct virtio_vsock, tx_work);
> + struct virtqueue *vq;
> + bool added = false;
> +
> + vq = vsock->vqs[VSOCK_VQ_TX];
> + mutex_lock(&vsock->tx_lock);
> +
> + if (vsock->tx_run)
> + added = virtio_transport_free_pkt_batch(vq);
> +
> mutex_unlock(&vsock->tx_lock);
>
> if (added)
> queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
> }
>
> +static void virtio_transport_dgram_tx_work(struct work_struct *work)
> +{
> + struct virtio_vsock *vsock =
> + container_of(work, struct virtio_vsock, dgram_tx_work);
> + struct virtqueue *vq;
> +
> + vq = vsock->vqs[VSOCK_VQ_DGRAM_TX];
> + mutex_lock(&vsock->dgram_tx_lock);
> +
> + if (vsock->dgram_tx_run)
> + virtio_transport_free_pkt_batch(vq);
> +
> + mutex_unlock(&vsock->dgram_tx_lock);
> +}
> +
> /* Is there space left for replies to rx packets? */
> static bool virtio_transport_more_replies(struct virtio_vsock *vsock)
> {
> @@ -453,6 +602,11 @@ static void virtio_vsock_tx_done(struct virtqueue *vq)
>
> static void virtio_vsock_dgram_tx_done(struct virtqueue *vq)
> {
> + struct virtio_vsock *vsock = vq->vdev->priv;
> +
> + if (!vsock)
> + return;
> + queue_work(virtio_vsock_workqueue, &vsock->dgram_tx_work);
> }
>
> static void virtio_vsock_rx_done(struct virtqueue *vq)
> @@ -468,8 +622,12 @@ static bool virtio_transport_seqpacket_allow(u32 remote_cid);
>
> static void virtio_vsock_dgram_rx_done(struct virtqueue *vq)
> {
> -}
> + struct virtio_vsock *vsock = vq->vdev->priv;
>
> + if (!vsock)
> + return;
> + queue_work(virtio_vsock_workqueue, &vsock->dgram_rx_work);
> +}
> static struct virtio_transport virtio_transport = {
> .transport = {
> .module = THIS_MODULE,
> @@ -532,19 +690,9 @@ static bool virtio_transport_seqpacket_allow(u32 remote_cid)
> return seqpacket_allow;
> }
>
> -static void virtio_transport_rx_work(struct work_struct *work)
> +static void virtio_transport_do_rx_work(struct virtio_vsock *vsock,
> + struct virtqueue *vq, bool is_dgram)
> {
> - struct virtio_vsock *vsock =
> - container_of(work, struct virtio_vsock, rx_work);
> - struct virtqueue *vq;
> -
> - vq = vsock->vqs[VSOCK_VQ_RX];
> -
> - mutex_lock(&vsock->rx_lock);
> -
> - if (!vsock->rx_run)
> - goto out;
> -
> do {
> virtqueue_disable_cb(vq);
> for (;;) {
> @@ -564,7 +712,10 @@ static void virtio_transport_rx_work(struct work_struct *work)
> break;
> }
>
> - vsock->rx_buf_nr--;
> + if (is_dgram)
> + vsock->dgram_rx_buf_nr--;
> + else
> + vsock->rx_buf_nr--;
>
> /* Drop short/long packets */
> if (unlikely(len < sizeof(pkt->hdr) ||
> @@ -580,11 +731,45 @@ static void virtio_transport_rx_work(struct work_struct *work)
> } while (!virtqueue_enable_cb(vq));
>
> out:
> + return;
> +}
> +
> +static void virtio_transport_rx_work(struct work_struct *work)
> +{
> + struct virtio_vsock *vsock =
> + container_of(work, struct virtio_vsock, rx_work);
> + struct virtqueue *vq;
> +
> + vq = vsock->vqs[VSOCK_VQ_RX];
> +
> + mutex_lock(&vsock->rx_lock);
> +
> + if (vsock->rx_run)
> + virtio_transport_do_rx_work(vsock, vq, false);
> +
> if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
> - virtio_vsock_rx_fill(vsock);
> + virtio_vsock_rx_fill(vsock, false);
> mutex_unlock(&vsock->rx_lock);
> }
>
> +static void virtio_transport_dgram_rx_work(struct work_struct *work)
> +{
> + struct virtio_vsock *vsock =
> + container_of(work, struct virtio_vsock, dgram_rx_work);
> + struct virtqueue *vq;
> +
> + vq = vsock->vqs[VSOCK_VQ_DGRAM_RX];
> +
> + mutex_lock(&vsock->dgram_rx_lock);
> +
> + if (vsock->dgram_rx_run)
> + virtio_transport_do_rx_work(vsock, vq, true);
> +
> + if (vsock->dgram_rx_buf_nr < vsock->dgram_rx_buf_max_nr / 2)
> + virtio_vsock_rx_fill(vsock, true);
> + mutex_unlock(&vsock->dgram_rx_lock);
> +}
> +
> static int virtio_vsock_probe(struct virtio_device *vdev)
> {
> vq_callback_t *callbacks[] = {
> @@ -592,7 +777,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
> virtio_vsock_tx_done,
> virtio_vsock_event_done,
> };
> - vq_callback_t *ex_callbacks[] = {
> + vq_callback_t *dgram_callbacks[] = {
> virtio_vsock_rx_done,
> virtio_vsock_tx_done,
> virtio_vsock_dgram_rx_done,
> @@ -651,7 +836,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
>
> if (vsock->has_dgram) {
> ret = virtio_find_vqs(vsock->vdev, max_vq,
> - vsock->vqs, ex_callbacks, ex_names,
> + vsock->vqs, dgram_callbacks, ex_names,
> NULL);
> } else {
> ret = virtio_find_vqs(vsock->vdev, max_vq,
> @@ -668,8 +853,14 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
> vsock->rx_buf_max_nr = 0;
> atomic_set(&vsock->queued_replies, 0);
>
> + vsock->dgram_rx_buf_nr = 0;
> + vsock->dgram_rx_buf_max_nr = 0;
> + atomic_set(&vsock->dgram_queued_replies, 0);

Seems to be the only use of dgram_queued_replies. why do we bother then?

> +
> mutex_init(&vsock->tx_lock);
> mutex_init(&vsock->rx_lock);
> + mutex_init(&vsock->dgram_tx_lock);
> + mutex_init(&vsock->dgram_rx_lock);
> mutex_init(&vsock->event_lock);
> spin_lock_init(&vsock->send_pkt_list_lock);
> INIT_LIST_HEAD(&vsock->send_pkt_list);
> @@ -677,16 +868,27 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
> INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
> INIT_WORK(&vsock->event_work, virtio_transport_event_work);
> INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
> + INIT_WORK(&vsock->dgram_rx_work, virtio_transport_dgram_rx_work);
> + INIT_WORK(&vsock->dgram_tx_work, virtio_transport_dgram_tx_work);
>
> mutex_lock(&vsock->tx_lock);
> vsock->tx_run = true;
> mutex_unlock(&vsock->tx_lock);
>
> + mutex_lock(&vsock->dgram_tx_lock);
> + vsock->dgram_tx_run = true;
> + mutex_unlock(&vsock->dgram_tx_lock);
> +
> mutex_lock(&vsock->rx_lock);
> - virtio_vsock_rx_fill(vsock);
> + virtio_vsock_rx_fill(vsock, false);
> vsock->rx_run = true;
> mutex_unlock(&vsock->rx_lock);
>
> + mutex_lock(&vsock->dgram_rx_lock);
> + virtio_vsock_rx_fill(vsock, true);
> + vsock->dgram_rx_run = true;
> + mutex_unlock(&vsock->dgram_rx_lock);
> +
> mutex_lock(&vsock->event_lock);
> virtio_vsock_event_fill(vsock);
> vsock->event_run = true;
> @@ -698,6 +900,9 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
> vdev->priv = vsock;
> rcu_assign_pointer(the_virtio_vsock, vsock);
>
> + the_virtio_vsock_dgram = vsock;
> + refcount_set(&the_virtio_vsock_dgram->active, 1);
> +
> mutex_unlock(&the_virtio_vsock_mutex);
>
> return 0;
> @@ -729,14 +934,27 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
> vsock->rx_run = false;
> mutex_unlock(&vsock->rx_lock);
>
> + mutex_lock(&vsock->dgram_rx_lock);
> + vsock->dgram_rx_run = false;
> + mutex_unlock(&vsock->dgram_rx_lock);
> +
> mutex_lock(&vsock->tx_lock);
> vsock->tx_run = false;
> mutex_unlock(&vsock->tx_lock);
>
> + mutex_lock(&vsock->dgram_tx_lock);
> + vsock->dgram_tx_run = false;
> + mutex_unlock(&vsock->dgram_tx_lock);
> +
> mutex_lock(&vsock->event_lock);
> vsock->event_run = false;
> mutex_unlock(&vsock->event_lock);
>
> + while (!refcount_dec_if_one(&the_virtio_vsock_dgram->active)) {
> + if (signal_pending(current))
> + break;
> + }
> +
> /* Flush all device writes and interrupts, device will not use any
> * more buffers.
> */
> @@ -747,11 +965,21 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
> virtio_transport_free_pkt(pkt);
> mutex_unlock(&vsock->rx_lock);
>
> + mutex_lock(&vsock->dgram_rx_lock);
> + while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_DGRAM_RX])))
> + virtio_transport_free_pkt(pkt);
> + mutex_unlock(&vsock->dgram_rx_lock);
> +
> mutex_lock(&vsock->tx_lock);
> while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_TX])))
> virtio_transport_free_pkt(pkt);
> mutex_unlock(&vsock->tx_lock);
>
> + mutex_lock(&vsock->dgram_tx_lock);
> + while ((pkt = virtqueue_detach_unused_buf(vsock->vqs[VSOCK_VQ_DGRAM_TX])))
> + virtio_transport_free_pkt(pkt);
> + mutex_unlock(&vsock->dgram_tx_lock);
> +
> spin_lock_bh(&vsock->send_pkt_list_lock);
> while (!list_empty(&vsock->send_pkt_list)) {
> pkt = list_first_entry(&vsock->send_pkt_list,
> @@ -769,6 +997,8 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
> */
> flush_work(&vsock->rx_work);
> flush_work(&vsock->tx_work);
> + flush_work(&vsock->dgram_rx_work);
> + flush_work(&vsock->dgram_tx_work);
> flush_work(&vsock->event_work);
> flush_work(&vsock->send_pkt_work);
>
> @@ -806,7 +1036,7 @@ static int __init virtio_vsock_init(void)
> return -ENOMEM;
>
> ret = vsock_core_register(&virtio_transport.transport,
> - VSOCK_TRANSPORT_F_G2H);
> + VSOCK_TRANSPORT_F_G2H | VSOCK_TRANSPORT_F_DGRAM);
> if (ret)
> goto out_wq;
>
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index 081e7ae93cb1..034de35fe7c8 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -26,6 +26,8 @@
> /* Threshold for detecting small packets to copy */
> #define GOOD_COPY_LEN 128
>
> +static s64 virtio_transport_dgram_has_data(struct vsock_sock *vsk);
> +
> static const struct virtio_transport *
> virtio_transport_get_ops(struct vsock_sock *vsk)
> {
> @@ -210,21 +212,28 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
> vvs = vsk->trans;
>
> /* we can send less than pkt_len bytes */
> - if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
> - pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
> + if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
> + if (info->type == VIRTIO_VSOCK_TYPE_STREAM)
> + pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
> + else
> + return 0;
> + }
>
> - /* virtio_transport_get_credit might return less than pkt_len credit */
> - pkt_len = virtio_transport_get_credit(vvs, pkt_len);
> + if (info->type == VIRTIO_VSOCK_TYPE_STREAM) {
> + /* virtio_transport_get_credit might return less than pkt_len credit */
> + pkt_len = virtio_transport_get_credit(vvs, pkt_len);
>
> - /* Do not send zero length OP_RW pkt */
> - if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
> - return pkt_len;
> + /* Do not send zero length OP_RW pkt */
> + if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
> + return pkt_len;
> + }
>
> pkt = virtio_transport_alloc_pkt(info, pkt_len,
> src_cid, src_port,
> dst_cid, dst_port);
> if (!pkt) {
> - virtio_transport_put_credit(vvs, pkt_len);
> + if (info->type == VIRTIO_VSOCK_TYPE_STREAM)
> + virtio_transport_put_credit(vvs, pkt_len);
> return -ENOMEM;
> }
>
> @@ -474,6 +483,55 @@ static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
> return dequeued_len;
> }
>
> +static ssize_t
> +virtio_transport_dgram_do_dequeue(struct vsock_sock *vsk,
> + struct msghdr *msg, size_t len)
> +{
> + struct virtio_vsock_sock *vvs = vsk->trans;
> + struct virtio_vsock_pkt *pkt;
> + size_t total = 0;
> + int err = -EFAULT;
> +
> + spin_lock_bh(&vvs->rx_lock);
> + if (total < len && !list_empty(&vvs->rx_queue)) {
> + pkt = list_first_entry(&vvs->rx_queue,
> + struct virtio_vsock_pkt, list);
> +
> + total = len;
> + if (total > pkt->len - pkt->off)
> + total = pkt->len - pkt->off;
> + else if (total < pkt->len - pkt->off)
> + msg->msg_flags |= MSG_TRUNC;
> +
> + /* sk_lock is held by caller so no one else can dequeue.
> + * Unlock rx_lock since memcpy_to_msg() may sleep.
> + */
> + spin_unlock_bh(&vvs->rx_lock);
> +
> + err = memcpy_to_msg(msg, pkt->buf + pkt->off, total);
> + if (err)
> + return err;
> +
> + spin_lock_bh(&vvs->rx_lock);
> +
> + virtio_transport_dec_rx_pkt(vvs, pkt);
> + list_del(&pkt->list);
> + virtio_transport_free_pkt(pkt);
> + }
> +
> + spin_unlock_bh(&vvs->rx_lock);
> +
> + if (total > 0 && msg->msg_name) {
> + /* Provide the address of the sender. */
> + DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name);
> +
> + vsock_addr_init(vm_addr, le64_to_cpu(pkt->hdr.src_cid),
> + le32_to_cpu(pkt->hdr.src_port));
> + msg->msg_namelen = sizeof(*vm_addr);
> + }
> + return total;
> +}
> +
> ssize_t
> virtio_transport_stream_dequeue(struct vsock_sock *vsk,
> struct msghdr *msg,
> @@ -523,7 +581,66 @@ virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
> struct msghdr *msg,
> size_t len, int flags)
> {
> - return -EOPNOTSUPP;
> + struct sock *sk;
> + size_t err = 0;
> + long timeout;
> +
> + DEFINE_WAIT(wait);
> +
> + sk = &vsk->sk;
> + err = 0;
> +
> + lock_sock(sk);
> +
> + if (flags & MSG_OOB || flags & MSG_ERRQUEUE || flags & MSG_PEEK)
> + return -EOPNOTSUPP;
> +
> + if (!len)
> + goto out;
> +
> + timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
> +
> + while (1) {
> + s64 ready;
> +
> + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
> + ready = virtio_transport_dgram_has_data(vsk);
> +
> + if (ready == 0) {
> + if (timeout == 0) {
> + err = -EAGAIN;
> + finish_wait(sk_sleep(sk), &wait);
> + break;
> + }
> +
> + release_sock(sk);
> + timeout = schedule_timeout(timeout);
> + lock_sock(sk);
> +
> + if (signal_pending(current)) {
> + err = sock_intr_errno(timeout);
> + finish_wait(sk_sleep(sk), &wait);
> + break;
> + } else if (timeout == 0) {
> + err = -EAGAIN;
> + finish_wait(sk_sleep(sk), &wait);
> + break;
> + }
> + } else {
> + finish_wait(sk_sleep(sk), &wait);
> +
> + if (ready < 0) {
> + err = -ENOMEM;
> + goto out;
> + }
> +
> + err = virtio_transport_dgram_do_dequeue(vsk, msg, len);
> + break;
> + }
> + }
> +out:
> + release_sock(sk);
> + return err;
> }
> EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
>
> @@ -553,6 +670,11 @@ u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
> }
> EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
>
> +static s64 virtio_transport_dgram_has_data(struct vsock_sock *vsk)
> +{
> + return virtio_transport_stream_has_data(vsk);
> +}
> +
> static s64 virtio_transport_has_space(struct vsock_sock *vsk)
> {
> struct virtio_vsock_sock *vvs = vsk->trans;
> @@ -731,13 +853,15 @@ EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
> int virtio_transport_dgram_bind(struct vsock_sock *vsk,
> struct sockaddr_vm *addr)
> {
> - return -EOPNOTSUPP;
> + //use same stream bind for dgram
> + int ret = vsock_bind_stream(vsk, addr);
> + return ret;
> }
> EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
>
> bool virtio_transport_dgram_allow(u32 cid, u32 port)
> {
> - return false;
> + return true;
> }
> EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
>
> @@ -773,7 +897,17 @@ virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
> struct msghdr *msg,
> size_t dgram_len)
> {
> - return -EOPNOTSUPP;
> + struct virtio_vsock_pkt_info info = {
> + .op = VIRTIO_VSOCK_OP_RW,
> + .type = VIRTIO_VSOCK_TYPE_DGRAM,
> + .msg = msg,
> + .pkt_len = dgram_len,
> + .vsk = vsk,
> + .remote_cid = remote_addr->svm_cid,
> + .remote_port = remote_addr->svm_port,
> + };
> +
> + return virtio_transport_send_pkt_info(vsk, &info);
> }
> EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
>
> @@ -846,7 +980,6 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
> virtio_transport_free_pkt(reply);
> return -ENOTCONN;
> }
> -
> return t->send_pkt(reply);
> }
>
> @@ -1049,7 +1182,8 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
> * of a new record.
> */
> 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_EOR) &&
> + (le32_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_DGRAM)) {
> memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
> pkt->len);
> last_pkt->len += pkt->len;
> @@ -1074,6 +1208,12 @@ virtio_transport_recv_connected(struct sock *sk,
> struct vsock_sock *vsk = vsock_sk(sk);
> int err = 0;
>
> + if (le16_to_cpu(pkt->hdr.type) == VIRTIO_VSOCK_TYPE_DGRAM) {
> + virtio_transport_recv_enqueue(vsk, pkt);
> + sk->sk_data_ready(sk);
> + return err;
> + }
> +
> switch (le16_to_cpu(pkt->hdr.op)) {
> case VIRTIO_VSOCK_OP_RW:
> virtio_transport_recv_enqueue(vsk, pkt);
> @@ -1226,7 +1366,8 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt,
> static bool virtio_transport_valid_type(u16 type)
> {
> return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
> - (type == VIRTIO_VSOCK_TYPE_SEQPACKET);
> + (type == VIRTIO_VSOCK_TYPE_SEQPACKET) ||
> + (type == VIRTIO_VSOCK_TYPE_DGRAM);
> }
>
> /* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
> @@ -1289,11 +1430,16 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
> goto free_pkt;
> }
>
> - space_available = virtio_transport_space_update(sk, pkt);
> -
> /* Update CID in case it has changed after a transport reset event */
> vsk->local_addr.svm_cid = dst.svm_cid;
>
> + if (sk->sk_type == SOCK_DGRAM) {
> + virtio_transport_recv_connected(sk, pkt);
> + goto out;
> + }
> +
> + space_available = virtio_transport_space_update(sk, pkt);
> +
> if (space_available)
> sk->sk_write_space(sk);
>
> @@ -1319,6 +1465,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
> break;
> }
>
> +out:
> release_sock(sk);
>
> /* Release refcnt obtained when we fetched this socket out of the
> --
> 2.20.1