From: Asias He <as...@redhat.com>

VM sockets virtio transport implementation. This module runs in guest
kernel.

Signed-off-by: Asias He <as...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
v2:
 * Fix total_tx_buf accounting
 * Add virtio_transport global mutex to prevent races
---
 net/vmw_vsock/virtio_transport.c | 466 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 466 insertions(+)
 create mode 100644 net/vmw_vsock/virtio_transport.c

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
new file mode 100644
index 0000000..df65dca
--- /dev/null
+++ b/net/vmw_vsock/virtio_transport.c
@@ -0,0 +1,466 @@
+/*
+ * virtio transport for vsock
+ *
+ * Copyright (C) 2013-2015 Red Hat, Inc.
+ * Author: Asias He <as...@redhat.com>
+ *         Stefan Hajnoczi <stefa...@redhat.com>
+ *
+ * Some of the code is take from Gerd Hoffmann <kra...@redhat.com>'s
+ * early virtio-vsock proof-of-concept bits.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/spinlock.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ids.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_vsock.h>
+#include <net/sock.h>
+#include <linux/mutex.h>
+#include <net/af_vsock.h>
+
+static struct workqueue_struct *virtio_vsock_workqueue;
+static struct virtio_vsock *the_virtio_vsock;
+static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
+static void virtio_vsock_rx_fill(struct virtio_vsock *vsock);
+
+struct virtio_vsock {
+       /* Virtio device */
+       struct virtio_device *vdev;
+       /* Virtio virtqueue */
+       struct virtqueue *vqs[VSOCK_VQ_MAX];
+       /* Wait queue for send pkt */
+       wait_queue_head_t queue_wait;
+       /* Work item to send pkt */
+       struct work_struct tx_work;
+       /* Work item to recv pkt */
+       struct work_struct rx_work;
+       /* Mutex to protect send pkt*/
+       struct mutex tx_lock;
+       /* Mutex to protect recv pkt*/
+       struct mutex rx_lock;
+       /* Number of recv buffers */
+       int rx_buf_nr;
+       /* Number of max recv buffers */
+       int rx_buf_max_nr;
+       /* Used for global tx buf limitation */
+       u32 total_tx_buf;
+       /* Guest context id, just like guest ip address */
+       u32 guest_cid;
+};
+
+static struct virtio_vsock *virtio_vsock_get(void)
+{
+       return the_virtio_vsock;
+}
+
+static u32 virtio_transport_get_local_cid(void)
+{
+       struct virtio_vsock *vsock = virtio_vsock_get();
+
+       return vsock->guest_cid;
+}
+
+static int
+virtio_transport_send_pkt(struct vsock_sock *vsk,
+                         struct virtio_vsock_pkt_info *info)
+{
+       u32 src_cid, src_port, dst_cid, dst_port;
+       int ret, in_sg = 0, out_sg = 0;
+       struct virtio_transport *trans;
+       struct virtio_vsock_pkt *pkt;
+       struct virtio_vsock *vsock;
+       struct scatterlist hdr, buf, *sgs[2];
+       struct virtqueue *vq;
+       u32 pkt_len = info->pkt_len;
+       DEFINE_WAIT(wait);
+
+       vsock = virtio_vsock_get();
+       if (!vsock)
+               return -ENODEV;
+
+       src_cid = virtio_transport_get_local_cid();
+       src_port = vsk->local_addr.svm_port;
+       if (!info->remote_cid) {
+               dst_cid = vsk->remote_addr.svm_cid;
+               dst_port = vsk->remote_addr.svm_port;
+       } else {
+               dst_cid = info->remote_cid;
+               dst_port = info->remote_port;
+       }
+
+       trans = vsk->trans;
+       vq = vsock->vqs[VSOCK_VQ_TX];
+
+       if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
+               pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+       pkt_len = virtio_transport_get_credit(trans, pkt_len);
+       /* Do not send zero length OP_RW pkt*/
+       if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
+               return pkt_len;
+
+       /* Respect global tx buf limitation */
+       mutex_lock(&vsock->tx_lock);
+       while (pkt_len + vsock->total_tx_buf > VIRTIO_VSOCK_MAX_TX_BUF_SIZE) {
+               prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
+                                         TASK_UNINTERRUPTIBLE);
+               mutex_unlock(&vsock->tx_lock);
+               schedule();
+               mutex_lock(&vsock->tx_lock);
+               finish_wait(&vsock->queue_wait, &wait);
+       }
+       vsock->total_tx_buf += pkt_len;
+       mutex_unlock(&vsock->tx_lock);
+
+       pkt = virtio_transport_alloc_pkt(vsk, info, pkt_len,
+                                        src_cid, src_port,
+                                        dst_cid, dst_port);
+       if (!pkt) {
+               mutex_lock(&vsock->tx_lock);
+               vsock->total_tx_buf -= pkt_len;
+               mutex_unlock(&vsock->tx_lock);
+               virtio_transport_put_credit(trans, pkt_len);
+               return -ENOMEM;
+       }
+
+       pr_debug("%s:info->pkt_len= %d\n", __func__, info->pkt_len);
+
+       /* Will be released in virtio_transport_send_pkt_work */
+       sock_hold(&trans->vsk->sk);
+       virtio_transport_inc_tx_pkt(pkt);
+
+       /* Put pkt in the virtqueue */
+       sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
+       sgs[out_sg++] = &hdr;
+       if (info->msg && info->pkt_len > 0) {
+               sg_init_one(&buf, pkt->buf, pkt->len);
+               sgs[out_sg++] = &buf;
+       }
+
+       mutex_lock(&vsock->tx_lock);
+       while ((ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt,
+                                       GFP_KERNEL)) < 0) {
+               prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
+                                         TASK_UNINTERRUPTIBLE);
+               mutex_unlock(&vsock->tx_lock);
+               schedule();
+               mutex_lock(&vsock->tx_lock);
+               finish_wait(&vsock->queue_wait, &wait);
+       }
+       virtqueue_kick(vq);
+       mutex_unlock(&vsock->tx_lock);
+
+       return pkt_len;
+}
+
+static struct virtio_transport_pkt_ops virtio_ops = {
+       .send_pkt = virtio_transport_send_pkt,
+};
+
+static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
+{
+       int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+       struct virtio_vsock_pkt *pkt;
+       struct scatterlist hdr, buf, *sgs[2];
+       struct virtqueue *vq;
+       int ret;
+
+       vq = vsock->vqs[VSOCK_VQ_RX];
+
+       do {
+               pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+               if (!pkt) {
+                       pr_debug("%s: fail to allocate pkt\n", __func__);
+                       goto out;
+               }
+
+               /* TODO: use mergeable rx buffer */
+               pkt->buf = kmalloc(buf_len, GFP_KERNEL);
+               if (!pkt->buf) {
+                       pr_debug("%s: fail to allocate pkt->buf\n", __func__);
+                       goto err;
+               }
+
+               sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
+               sgs[0] = &hdr;
+
+               sg_init_one(&buf, pkt->buf, buf_len);
+               sgs[1] = &buf;
+               ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
+               if (ret)
+                       goto err;
+               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;
+out:
+       virtqueue_kick(vq);
+       return;
+err:
+       virtqueue_kick(vq);
+       virtio_transport_free_pkt(pkt);
+       return;
+}
+
+static void virtio_transport_send_pkt_work(struct work_struct *work)
+{
+       struct virtio_vsock *vsock =
+               container_of(work, struct virtio_vsock, tx_work);
+       struct virtio_vsock_pkt *pkt;
+       bool added = false;
+       struct virtqueue *vq;
+       unsigned int len;
+       struct sock *sk;
+
+       vq = vsock->vqs[VSOCK_VQ_TX];
+       mutex_lock(&vsock->tx_lock);
+       do {
+               virtqueue_disable_cb(vq);
+               while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
+                       sk = &pkt->trans->vsk->sk;
+                       virtio_transport_dec_tx_pkt(pkt);
+                       /* Release refcnt taken in virtio_transport_send_pkt */
+                       sock_put(sk);
+                       vsock->total_tx_buf -= pkt->len;
+                       virtio_transport_free_pkt(pkt);
+                       added = true;
+               }
+       } while (!virtqueue_enable_cb(vq));
+       mutex_unlock(&vsock->tx_lock);
+
+       if (added)
+               wake_up(&vsock->queue_wait);
+}
+
+static void virtio_transport_recv_pkt_work(struct work_struct *work)
+{
+       struct virtio_vsock *vsock =
+               container_of(work, struct virtio_vsock, rx_work);
+       struct virtio_vsock_pkt *pkt;
+       struct virtqueue *vq;
+       unsigned int len;
+
+       vq = vsock->vqs[VSOCK_VQ_RX];
+       mutex_lock(&vsock->rx_lock);
+       do {
+               virtqueue_disable_cb(vq);
+               while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
+                       pkt->len = len;
+                       virtio_transport_recv_pkt(pkt);
+                       vsock->rx_buf_nr--;
+               }
+       } while (!virtqueue_enable_cb(vq));
+
+       if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
+               virtio_vsock_rx_fill(vsock);
+       mutex_unlock(&vsock->rx_lock);
+}
+
+static void virtio_vsock_ctrl_done(struct virtqueue *vq)
+{
+}
+
+static void virtio_vsock_tx_done(struct virtqueue *vq)
+{
+       struct virtio_vsock *vsock = vq->vdev->priv;
+
+       if (!vsock)
+               return;
+       queue_work(virtio_vsock_workqueue, &vsock->tx_work);
+}
+
+static void virtio_vsock_rx_done(struct virtqueue *vq)
+{
+       struct virtio_vsock *vsock = vq->vdev->priv;
+
+       if (!vsock)
+               return;
+       queue_work(virtio_vsock_workqueue, &vsock->rx_work);
+}
+
+static int
+virtio_transport_socket_init(struct vsock_sock *vsk, struct vsock_sock *psk)
+{
+       struct virtio_transport *trans;
+       int ret;
+
+       ret = virtio_transport_do_socket_init(vsk, psk);
+       if (ret)
+               return ret;
+
+       trans = vsk->trans;
+       trans->ops = &virtio_ops;
+       return ret;
+}
+
+static struct vsock_transport virtio_transport = {
+       .get_local_cid            = virtio_transport_get_local_cid,
+
+       .init                     = virtio_transport_socket_init,
+       .destruct                 = virtio_transport_destruct,
+       .release                  = virtio_transport_release,
+       .connect                  = virtio_transport_connect,
+       .shutdown                 = virtio_transport_shutdown,
+
+       .dgram_bind               = virtio_transport_dgram_bind,
+       .dgram_dequeue            = virtio_transport_dgram_dequeue,
+       .dgram_enqueue            = virtio_transport_dgram_enqueue,
+       .dgram_allow              = virtio_transport_dgram_allow,
+
+       .stream_dequeue           = virtio_transport_stream_dequeue,
+       .stream_enqueue           = virtio_transport_stream_enqueue,
+       .stream_has_data          = virtio_transport_stream_has_data,
+       .stream_has_space         = virtio_transport_stream_has_space,
+       .stream_rcvhiwat          = virtio_transport_stream_rcvhiwat,
+       .stream_is_active         = virtio_transport_stream_is_active,
+       .stream_allow             = virtio_transport_stream_allow,
+
+       .notify_poll_in           = virtio_transport_notify_poll_in,
+       .notify_poll_out          = virtio_transport_notify_poll_out,
+       .notify_recv_init         = virtio_transport_notify_recv_init,
+       .notify_recv_pre_block    = virtio_transport_notify_recv_pre_block,
+       .notify_recv_pre_dequeue  = virtio_transport_notify_recv_pre_dequeue,
+       .notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
+       .notify_send_init         = virtio_transport_notify_send_init,
+       .notify_send_pre_block    = virtio_transport_notify_send_pre_block,
+       .notify_send_pre_enqueue  = virtio_transport_notify_send_pre_enqueue,
+       .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
+
+       .set_buffer_size          = virtio_transport_set_buffer_size,
+       .set_min_buffer_size      = virtio_transport_set_min_buffer_size,
+       .set_max_buffer_size      = virtio_transport_set_max_buffer_size,
+       .get_buffer_size          = virtio_transport_get_buffer_size,
+       .get_min_buffer_size      = virtio_transport_get_min_buffer_size,
+       .get_max_buffer_size      = virtio_transport_get_max_buffer_size,
+};
+
+static int virtio_vsock_probe(struct virtio_device *vdev)
+{
+       vq_callback_t *callbacks[] = {
+               virtio_vsock_ctrl_done,
+               virtio_vsock_rx_done,
+               virtio_vsock_tx_done,
+       };
+       const char *names[] = {
+               "ctrl",
+               "rx",
+               "tx",
+       };
+       struct virtio_vsock *vsock = NULL;
+       u32 guest_cid;
+       int ret;
+
+       ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
+       if (ret)
+               return ret;
+
+       /* Only one virtio-vsock device per guest is supported */
+       if (the_virtio_vsock) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
+       if (!vsock) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       vsock->vdev = vdev;
+
+       ret = vsock->vdev->config->find_vqs(vsock->vdev, VSOCK_VQ_MAX,
+                                           vsock->vqs, callbacks, names);
+       if (ret < 0)
+               goto out;
+
+       vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
+                         &guest_cid, sizeof(guest_cid));
+       vsock->guest_cid = le32_to_cpu(guest_cid);
+       pr_debug("%s:guest_cid=%d\n", __func__, vsock->guest_cid);
+
+       ret = vsock_core_init(&virtio_transport);
+       if (ret < 0)
+               goto out_vqs;
+
+       vsock->rx_buf_nr = 0;
+       vsock->rx_buf_max_nr = 0;
+
+       vdev->priv = the_virtio_vsock = vsock;
+       init_waitqueue_head(&vsock->queue_wait);
+       mutex_init(&vsock->tx_lock);
+       mutex_init(&vsock->rx_lock);
+       INIT_WORK(&vsock->rx_work, virtio_transport_recv_pkt_work);
+       INIT_WORK(&vsock->tx_work, virtio_transport_send_pkt_work);
+
+       mutex_lock(&vsock->rx_lock);
+       virtio_vsock_rx_fill(vsock);
+       mutex_unlock(&vsock->rx_lock);
+
+       mutex_unlock(&the_virtio_vsock_mutex);
+       return 0;
+
+out_vqs:
+       vsock->vdev->config->del_vqs(vsock->vdev);
+out:
+       kfree(vsock);
+       mutex_unlock(&the_virtio_vsock_mutex);
+       return ret;
+}
+
+static void virtio_vsock_remove(struct virtio_device *vdev)
+{
+       struct virtio_vsock *vsock = vdev->priv;
+
+       mutex_lock(&the_virtio_vsock_mutex);
+       the_virtio_vsock = NULL;
+       vsock_core_exit();
+       mutex_unlock(&the_virtio_vsock_mutex);
+
+       kfree(vsock);
+}
+
+static struct virtio_device_id id_table[] = {
+       { VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
+       { 0 },
+};
+
+static unsigned int features[] = {
+};
+
+static struct virtio_driver virtio_vsock_driver = {
+       .feature_table = features,
+       .feature_table_size = ARRAY_SIZE(features),
+       .driver.name = KBUILD_MODNAME,
+       .driver.owner = THIS_MODULE,
+       .id_table = id_table,
+       .probe = virtio_vsock_probe,
+       .remove = virtio_vsock_remove,
+};
+
+static int __init virtio_vsock_init(void)
+{
+       int ret;
+
+       virtio_vsock_workqueue = alloc_workqueue("virtio_vsock", 0, 0);
+       if (!virtio_vsock_workqueue)
+               return -ENOMEM;
+       ret = register_virtio_driver(&virtio_vsock_driver);
+       if (ret)
+               destroy_workqueue(virtio_vsock_workqueue);
+       return ret;
+}
+
+static void __exit virtio_vsock_exit(void)
+{
+       unregister_virtio_driver(&virtio_vsock_driver);
+       destroy_workqueue(virtio_vsock_workqueue);
+}
+
+module_init(virtio_vsock_init);
+module_exit(virtio_vsock_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("virtio transport for vsock");
+MODULE_DEVICE_TABLE(virtio, id_table);
-- 
2.5.0

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to