[RFC V2 5/7] VSOCK: Introduce vhost-vsock.ko

Asias He
2014-07-05T03:24:00Z

VM sockets vhost transport implementation. This module runs in host
kernel.

Signed-off-by: Asias He <asias@redhat.com>
---
drivers/vhost/vsock.c | 572 ++++++++++++++++++++++++++++++++++++++++++++++++++
drivers/vhost/vsock.h | 4 +
2 files changed, 576 insertions(+)
create mode 100644 drivers/vhost/vsock.c
create mode 100644 drivers/vhost/vsock.h

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
new file mode 100644
index 0000000..deffed9
--- /dev/null
+++ b/drivers/vhost/vsock.c
@@ -0,0 +1,572 @@
+/*
+ * vhost transport for vsock
+ *
+ * Copyright (C) 2013 Red Hat, Inc.
+ * Author: Asias He <asias@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ */
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <net/sock.h>
+#include <linux/virtio_vsock.h>
+#include <linux/vhost.h>
+
+#include <net/af_vsock.h>
+#include "vhost.h"
+#include "vsock.h"
+
+#define VHOST_VSOCK_DEFAULT_HOST_CID 2
+
+static int vhost_transport_socket_init(struct vsock_sock *vsk,
+ struct vsock_sock *psk);
+
+enum {
+ VHOST_VSOCK_FEATURES = VHOST_FEATURES,
+};
+
+/* Used to track all the vhost_vsock instances on the system. */
+static LIST_HEAD(vhost_vsock_list);
+static DEFINE_MUTEX(vhost_vsock_mutex);
+
+struct vhost_vsock_virtqueue {
+ struct vhost_virtqueue vq;
+};
+
+struct vhost_vsock {
+ /* Vhost device */
+ struct vhost_dev dev;
+ /* Vhost vsock virtqueue*/
+ struct vhost_vsock_virtqueue vqs[VSOCK_VQ_MAX];
+ /* Link to global vhost_vsock_list*/
+ struct list_head list;
+ /* Head for pkt from host to guest */
+ struct list_head send_pkt_list;
+ /* Work item to send pkt */
+ struct vhost_work send_pkt_work;
+ /* Wait queue for send pkt */
+ wait_queue_head_t queue_wait;
+ /* Used for global tx buf limitation */
+ u32 total_tx_buf;
+ /* Guest contex id this vhost_vsock instance handles */
+ u32 guest_cid;
+};
+
+static u32 vhost_transport_get_local_cid(void)
+{
+ u32 cid = VHOST_VSOCK_DEFAULT_HOST_CID;
+ return cid;
+}
+
+static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
+{
+ struct vhost_vsock *vsock;
+
+ mutex_lock(&vhost_vsock_mutex);
+ list_for_each_entry(vsock, &vhost_vsock_list, list) {
+ if (vsock->guest_cid == guest_cid) {
+ mutex_unlock(&vhost_vsock_mutex);
+ return vsock;
+ }
+ }
+ mutex_unlock(&vhost_vsock_mutex);
+
+ return NULL;
+}
+
+static void
+vhost_transport_do_send_pkt(struct vhost_vsock *vsock,
+ struct vhost_virtqueue *vq)
+{
+ struct virtio_vsock_pkt *pkt;
+ bool added = false;
+ unsigned out, in;
+ struct sock *sk;
+ int head, ret;
+
+ mutex_lock(&vq->mutex);
+ vhost_disable_notify(&vsock->dev, vq);
+ for (;;) {
+ if (list_empty(&vsock->send_pkt_list)) {
+ vhost_enable_notify(&vsock->dev, vq);
+ break;
+ }
+
+ head = vhost_get_vq_desc(&vsock->dev, vq, vq->iov,
+ ARRAY_SIZE(vq->iov), &out, &in,
+ NULL, NULL);
+ pr_debug("%s: head = %d\n", __func__, head);
+ if (head < 0)
+ break;
+
+ if (head == vq->num) {
+ if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
+ vhost_disable_notify(&vsock->dev, vq);
+ continue;
+ }
+ break;
+ }
+
+ pkt = list_first_entry(&vsock->send_pkt_list,
+ struct virtio_vsock_pkt, list);
+ list_del_init(&pkt->list);
+
+ /* FIXME: no assumption of frame layout */
+ ret = __copy_to_user(vq->iov[0].iov_base, &pkt->hdr,
+ sizeof(pkt->hdr));
+ if (ret) {
+ virtio_transport_free_pkt(pkt);
+ vq_err(vq, "Faulted on copying pkt hdr\n");
+ break;
+ }
+ if (pkt->buf && pkt->len > 0) {
+ ret = __copy_to_user(vq->iov[1].iov_base, pkt->buf,
+ pkt->len);
+ if (ret) {
+ virtio_transport_free_pkt(pkt);
+ vq_err(vq, "Faulted on copying pkt buf\n");
+ break;
+ }
+ }
+
+ vhost_add_used(vq, head, pkt->len);
+ added = true;
+
+ virtio_transport_dec_tx_pkt(pkt);
+ vsock->total_tx_buf -= pkt->len;
+
+ sk = sk_vsock(pkt->trans->vsk);
+ /* Release refcnt taken in vhost_transport_send_pkt */
+ sock_put(sk);
+
+ virtio_transport_free_pkt(pkt);
+ }
+ if (added)
+ vhost_signal(&vsock->dev, vq);
+ mutex_unlock(&vq->mutex);
+
+ if (added)
+ wake_up(&vsock->queue_wait);
+}
+
+static void vhost_transport_send_pkt_work(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq;
+ struct vhost_vsock *vsock;
+
+ vsock = container_of(work, struct vhost_vsock, send_pkt_work);
+ vq = &vsock->vqs[VSOCK_VQ_RX].vq;
+
+ vhost_transport_do_send_pkt(vsock, vq);
+}
+
+static int
+vhost_transport_send_pkt(struct vsock_sock *vsk,
+ struct virtio_vsock_pkt_info *info)
+{
+ u32 src_cid, src_port, dst_cid, dst_port;
+ struct virtio_transport *trans;
+ struct virtio_vsock_pkt *pkt;
+ struct vhost_virtqueue *vq;
+ struct vhost_vsock *vsock;
+ u32 pkt_len = info->pkt_len;
+ DEFINE_WAIT(wait);
+
+ src_cid = vhost_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;
+ }
+
+ /* Find the vhost_vsock according to guest context id */
+ vsock = vhost_vsock_get(dst_cid);
+ if (!vsock)
+ return -ENODEV;
+
+ trans = vsk->trans;
+ vq = &vsock->vqs[VSOCK_VQ_RX].vq;
+
+ /* we can send less than pkt_len bytes */
+ if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
+ pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
+
+ /* virtio_transport_get_credit might return less than pkt_len credit */
+ 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(&vq->mutex);
+ 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(&vq->mutex);
+ schedule();
+ mutex_lock(&vq->mutex);
+ finish_wait(&vsock->queue_wait, &wait);
+ }
+ vsock->total_tx_buf += pkt_len;
+ mutex_unlock(&vq->mutex);
+
+ pkt = virtio_transport_alloc_pkt(vsk, info, pkt_len,
+ src_cid, src_port,
+ dst_cid, dst_port);
+ if (!pkt) {
+ virtio_transport_put_credit(trans, pkt_len);
+ return -ENOMEM;
+ }
+
+ pr_debug("%s:info->pkt_len= %d\n", __func__, pkt_len);
+ /* Released in vhost_transport_do_send_pkt */
+ sock_hold(&trans->vsk->sk);
+ virtio_transport_inc_tx_pkt(pkt);
+
+ /* Queue it up in vhost work */
+ mutex_lock(&vq->mutex);
+ list_add_tail(&pkt->list, &vsock->send_pkt_list);
+ vhost_work_queue(&vsock->dev, &vsock->send_pkt_work);
+ mutex_unlock(&vq->mutex);
+
+ return pkt_len;
+}
+
+static struct virtio_transport_pkt_ops vhost_ops = {
+ .send_pkt = vhost_transport_send_pkt,
+};
+
+static struct virtio_vsock_pkt *
+vhost_vsock_alloc_pkt(struct vhost_virtqueue *vq)
+{
+ struct virtio_vsock_pkt *pkt;
+ int ret;
+ int len;
+
+ pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+ if (!pkt)
+ return NULL;
+
+ len = sizeof(pkt->hdr);
+ if (unlikely(vq->iov[0].iov_len != len)) {
+ vq_err(vq, "Expecting pkt->hdr = %d, got %zu bytes\n",
+ len, vq->iov[0].iov_len);
+ kfree(pkt);
+ return NULL;
+ }
+ ret = __copy_from_user(&pkt->hdr, vq->iov[0].iov_base, len);
+ if (ret) {
+ vq_err(vq, "Faulted on virtio_vsock_hdr\n");
+ kfree(pkt);
+ return NULL;
+ }
+
+ if (le16_to_cpu(pkt->hdr.type) == SOCK_DGRAM)
+ pkt->len = le32_to_cpu(pkt->hdr.len) & 0XFFFF;
+ else if (le16_to_cpu(pkt->hdr.type) == SOCK_STREAM)
+ pkt->len = le32_to_cpu(pkt->hdr.len);
+
+ /* No payload */
+ if (!pkt->len)
+ return pkt;
+
+ /* The pkt is too big */
+ if (pkt->len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
+ kfree(pkt);
+ return NULL;
+ }
+
+ pkt->buf = kmalloc(pkt->len, GFP_KERNEL);
+ if (!pkt->buf) {
+ kfree(pkt);
+ return NULL;
+ }
+
+ ret = __copy_from_user(pkt->buf, vq->iov[1].iov_base, pkt->len);
+ if (ret) {
+ vq_err(vq, "Faulted on virtio_vsock_hdr\n");
+ virtio_transport_free_pkt(pkt);
+ }
+
+ return pkt;
+}
+
+static void vhost_vsock_handle_ctl_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
+ dev);
+
+ pr_debug("%s vq=%p, vsock=%p\n", __func__, vq, vsock);
+}
+
+static void vhost_vsock_handle_tx_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
+ dev);
+ struct virtio_vsock_pkt *pkt;
+ int head, out, in;
+ bool added = false;
+ u32 len;
+
+ mutex_lock(&vq->mutex);
+ vhost_disable_notify(&vsock->dev, vq);
+ for (;;) {
+ head = vhost_get_vq_desc(&vsock->dev, vq, vq->iov,
+ ARRAY_SIZE(vq->iov), &out, &in,
+ NULL, NULL);
+ if (head < 0)
+ break;
+
+ if (head == vq->num) {
+ if (unlikely(vhost_enable_notify(&vsock->dev, vq))) {
+ vhost_disable_notify(&vsock->dev, vq);
+ continue;
+ }
+ break;
+ }
+
+ pkt = vhost_vsock_alloc_pkt(vq);
+ if (!pkt) {
+ vq_err(vq, "Faulted on pkt\n");
+ continue;
+ }
+
+ len = pkt->len;
+ virtio_transport_recv_pkt(pkt);
+ vhost_add_used(vq, head, len);
+ added = true;
+ }
+ if (added)
+ vhost_signal(&vsock->dev, vq);
+ mutex_unlock(&vq->mutex);
+}
+
+static void vhost_vsock_handle_rx_kick(struct vhost_work *work)
+{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_vsock *vsock = container_of(vq->dev, struct vhost_vsock,
+ dev);
+
+ vhost_transport_do_send_pkt(vsock, vq);
+}
+
+static int vhost_vsock_dev_open(struct inode *inode, struct file *file)
+{
+ struct vhost_virtqueue **vqs;
+ struct vhost_vsock *vsock;
+ int ret;
+
+ vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
+ if (!vsock)
+ return -ENOMEM;
+
+ pr_debug("%s:vsock=%p\n", __func__, vsock);
+
+ vqs = kmalloc(VSOCK_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
+ if (!vqs) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ vqs[VSOCK_VQ_CTRL] = &vsock->vqs[VSOCK_VQ_CTRL].vq;
+ vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX].vq;
+ vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX].vq;
+ vsock->vqs[VSOCK_VQ_CTRL].vq.handle_kick = vhost_vsock_handle_ctl_kick;
+ vsock->vqs[VSOCK_VQ_TX].vq.handle_kick = vhost_vsock_handle_tx_kick;
+ vsock->vqs[VSOCK_VQ_RX].vq.handle_kick = vhost_vsock_handle_rx_kick;
+
+ ret = vhost_dev_init(&vsock->dev, vqs, VSOCK_VQ_MAX);
+ if (ret < 0)
+ goto out_vqs;
+
+ file->private_data = vsock;
+ init_waitqueue_head(&vsock->queue_wait);
+ INIT_LIST_HEAD(&vsock->send_pkt_list);
+ vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work);
+
+ mutex_lock(&vhost_vsock_mutex);
+ list_add_tail(&vsock->list, &vhost_vsock_list);
+ mutex_unlock(&vhost_vsock_mutex);
+ return ret;
+
+out_vqs:
+ kfree(vqs);
+out:
+ kfree(vsock);
+ return ret;
+}
+
+static void vhost_vsock_flush(struct vhost_vsock *vsock)
+{
+ int i;
+
+ for (i = 0; i < VSOCK_VQ_MAX; i++)
+ vhost_poll_flush(&vsock->vqs[i].vq.poll);
+ vhost_work_flush(&vsock->dev, &vsock->send_pkt_work);
+}
+
+static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
+{
+ struct vhost_vsock *vsock = file->private_data;
+
+ mutex_lock(&vhost_vsock_mutex);
+ list_del(&vsock->list);
+ mutex_unlock(&vhost_vsock_mutex);
+
+ vhost_dev_stop(&vsock->dev);
+ vhost_vsock_flush(vsock);
+ vhost_dev_cleanup(&vsock->dev, false);
+ kfree(vsock->dev.vqs);
+ kfree(vsock);
+ return 0;
+}
+
+static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u32 guest_cid)
+{
+ mutex_lock(&vhost_vsock_mutex);
+ vsock->guest_cid = guest_cid;
+ pr_debug("%s:guest_cid=%d\n", __func__, guest_cid);
+ mutex_unlock(&vhost_vsock_mutex);
+
+ return 0;
+}
+
+static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl,
+ unsigned long arg)
+{
+ struct vhost_vsock *vsock = f->private_data;
+ void __user *argp = (void __user *)arg;
+ u64 __user *featurep = argp;
+ u32 __user *cidp = argp;
+ u32 guest_cid;
+ u64 features;
+ int r;
+
+ switch (ioctl) {
+ case VHOST_VSOCK_SET_GUEST_CID:
+ if (get_user(guest_cid, cidp))
+ return -EFAULT;
+ return vhost_vsock_set_cid(vsock, guest_cid);
+ case VHOST_GET_FEATURES:
+ features = VHOST_VSOCK_FEATURES;
+ if (copy_to_user(featurep, &features, sizeof(features)))
+ return -EFAULT;
+ return 0;
+ case VHOST_SET_FEATURES:
+ if (copy_from_user(&features, featurep, sizeof(features)))
+ return -EFAULT;
+ return 0;
+ default:
+ mutex_lock(&vsock->dev.mutex);
+ r = vhost_dev_ioctl(&vsock->dev, ioctl, argp);
+ if (r == -ENOIOCTLCMD)
+ r = vhost_vring_ioctl(&vsock->dev, ioctl, argp);
+ else
+ vhost_vsock_flush(vsock);
+ mutex_unlock(&vsock->dev.mutex);
+ return r;
+ }
+}
+
+static const struct file_operations vhost_vsock_fops = {
+ .owner = THIS_MODULE,
+ .open = vhost_vsock_dev_open,
+ .release = vhost_vsock_dev_release,
+ .llseek = noop_llseek,
+ .unlocked_ioctl = vhost_vsock_dev_ioctl,
+};
+
+static struct miscdevice vhost_vsock_misc = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "vhost-vsock",
+ .fops = &vhost_vsock_fops,
+};
+
+static int
+vhost_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 = &vhost_ops;
+
+ return ret;
+}
+
+static struct vsock_transport vhost_transport = {
+ .get_local_cid = vhost_transport_get_local_cid,
+
+ .init = vhost_transport_socket_init,
+ .destruct = virtio_transport_destruct,
+ .release = virtio_transport_release,
+ .connect = virtio_transport_connect,
+ .shutdown = virtio_transport_shutdown,
+
+ .dgram_enqueue = virtio_transport_dgram_enqueue,
+ .dgram_dequeue = virtio_transport_dgram_dequeue,
+ .dgram_bind = virtio_transport_dgram_bind,
+ .dgram_allow = virtio_transport_dgram_allow,
+
+ .stream_enqueue = virtio_transport_stream_enqueue,
+ .stream_dequeue = virtio_transport_stream_dequeue,
+ .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 __init vhost_vsock_init(void)
+{
+ int ret;
+
+ ret = vsock_core_init(&vhost_transport);
+ if (ret < 0)
+ return ret;
+ return misc_register(&vhost_vsock_misc);
+};
+
+static void __exit vhost_vsock_exit(void)
+{
+ misc_deregister(&vhost_vsock_misc);
+ vsock_core_exit();
+};
+
+module_init(vhost_vsock_init);
+module_exit(vhost_vsock_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Asias He");
+MODULE_DESCRIPTION("vhost transport for vsock ");
diff --git a/drivers/vhost/vsock.h b/drivers/vhost/vsock.h
new file mode 100644
index 0000000..0ddb107
--- /dev/null
+++ b/drivers/vhost/vsock.h
@@ -0,0 +1,4 @@
+#ifndef VHOST_VSOCK_H
+#define VHOST_VSOCK_H
+#define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u32)
+#endif
--
1.9.3