VSOCK: Introduce virtio-vsock.ko
VM sockets virtio transport implementation. This module runs in guest kernel. Signed-off-by: Asias He <asias@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Asias He
David S. Miller
Родитель
80a19e338d
Коммит
32e61b06b6
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@ -0,0 +1,466 @@
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/*
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* virtio transport for vsock
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*
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* Copyright (C) 2013-2015 Red Hat, Inc.
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* Author: Asias He <asias@redhat.com>
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* Stefan Hajnoczi <stefanha@redhat.com>
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*
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* Some of the code is take from Gerd Hoffmann <kraxel@redhat.com>'s
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* early virtio-vsock proof-of-concept bits.
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*
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* This work is licensed under the terms of the GNU GPL, version 2.
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*/
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/virtio.h>
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#include <linux/virtio_ids.h>
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#include <linux/virtio_config.h>
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#include <linux/virtio_vsock.h>
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#include <net/sock.h>
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#include <linux/mutex.h>
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#include <net/af_vsock.h>
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static struct workqueue_struct *virtio_vsock_workqueue;
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static struct virtio_vsock *the_virtio_vsock;
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static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */
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static void virtio_vsock_rx_fill(struct virtio_vsock *vsock);
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struct virtio_vsock {
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/* Virtio device */
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struct virtio_device *vdev;
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/* Virtio virtqueue */
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struct virtqueue *vqs[VSOCK_VQ_MAX];
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/* Wait queue for send pkt */
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wait_queue_head_t queue_wait;
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/* Work item to send pkt */
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struct work_struct tx_work;
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/* Work item to recv pkt */
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struct work_struct rx_work;
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/* Mutex to protect send pkt*/
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struct mutex tx_lock;
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/* Mutex to protect recv pkt*/
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struct mutex rx_lock;
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/* Number of recv buffers */
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int rx_buf_nr;
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/* Number of max recv buffers */
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int rx_buf_max_nr;
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/* Used for global tx buf limitation */
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u32 total_tx_buf;
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/* Guest context id, just like guest ip address */
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u32 guest_cid;
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};
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static struct virtio_vsock *virtio_vsock_get(void)
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{
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return the_virtio_vsock;
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}
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static u32 virtio_transport_get_local_cid(void)
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{
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struct virtio_vsock *vsock = virtio_vsock_get();
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return vsock->guest_cid;
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}
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static int
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virtio_transport_send_pkt(struct vsock_sock *vsk,
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struct virtio_vsock_pkt_info *info)
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{
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u32 src_cid, src_port, dst_cid, dst_port;
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int ret, in_sg = 0, out_sg = 0;
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struct virtio_transport *trans;
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struct virtio_vsock_pkt *pkt;
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struct virtio_vsock *vsock;
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struct scatterlist hdr, buf, *sgs[2];
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struct virtqueue *vq;
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u32 pkt_len = info->pkt_len;
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DEFINE_WAIT(wait);
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vsock = virtio_vsock_get();
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if (!vsock)
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return -ENODEV;
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src_cid = virtio_transport_get_local_cid();
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src_port = vsk->local_addr.svm_port;
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if (!info->remote_cid) {
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dst_cid = vsk->remote_addr.svm_cid;
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dst_port = vsk->remote_addr.svm_port;
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} else {
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dst_cid = info->remote_cid;
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dst_port = info->remote_port;
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}
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trans = vsk->trans;
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vq = vsock->vqs[VSOCK_VQ_TX];
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if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE)
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pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
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pkt_len = virtio_transport_get_credit(trans, pkt_len);
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/* Do not send zero length OP_RW pkt*/
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if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
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return pkt_len;
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/* Respect global tx buf limitation */
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mutex_lock(&vsock->tx_lock);
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while (pkt_len + vsock->total_tx_buf > VIRTIO_VSOCK_MAX_TX_BUF_SIZE) {
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prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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mutex_unlock(&vsock->tx_lock);
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schedule();
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mutex_lock(&vsock->tx_lock);
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finish_wait(&vsock->queue_wait, &wait);
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}
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vsock->total_tx_buf += pkt_len;
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mutex_unlock(&vsock->tx_lock);
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pkt = virtio_transport_alloc_pkt(vsk, info, pkt_len,
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src_cid, src_port,
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dst_cid, dst_port);
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if (!pkt) {
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mutex_lock(&vsock->tx_lock);
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vsock->total_tx_buf -= pkt_len;
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mutex_unlock(&vsock->tx_lock);
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virtio_transport_put_credit(trans, pkt_len);
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return -ENOMEM;
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}
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pr_debug("%s:info->pkt_len= %d\n", __func__, info->pkt_len);
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/* Will be released in virtio_transport_send_pkt_work */
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sock_hold(&trans->vsk->sk);
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virtio_transport_inc_tx_pkt(pkt);
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/* Put pkt in the virtqueue */
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sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
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sgs[out_sg++] = &hdr;
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if (info->msg && info->pkt_len > 0) {
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sg_init_one(&buf, pkt->buf, pkt->len);
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sgs[out_sg++] = &buf;
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}
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mutex_lock(&vsock->tx_lock);
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while ((ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, pkt,
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GFP_KERNEL)) < 0) {
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prepare_to_wait_exclusive(&vsock->queue_wait, &wait,
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TASK_UNINTERRUPTIBLE);
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mutex_unlock(&vsock->tx_lock);
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schedule();
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mutex_lock(&vsock->tx_lock);
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finish_wait(&vsock->queue_wait, &wait);
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}
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virtqueue_kick(vq);
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mutex_unlock(&vsock->tx_lock);
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return pkt_len;
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}
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static struct virtio_transport_pkt_ops virtio_ops = {
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.send_pkt = virtio_transport_send_pkt,
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};
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static void virtio_vsock_rx_fill(struct virtio_vsock *vsock)
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{
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int buf_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE;
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struct virtio_vsock_pkt *pkt;
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struct scatterlist hdr, buf, *sgs[2];
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struct virtqueue *vq;
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int ret;
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vq = vsock->vqs[VSOCK_VQ_RX];
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do {
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pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
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if (!pkt) {
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pr_debug("%s: fail to allocate pkt\n", __func__);
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goto out;
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}
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/* TODO: use mergeable rx buffer */
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pkt->buf = kmalloc(buf_len, GFP_KERNEL);
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if (!pkt->buf) {
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pr_debug("%s: fail to allocate pkt->buf\n", __func__);
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goto err;
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}
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sg_init_one(&hdr, &pkt->hdr, sizeof(pkt->hdr));
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sgs[0] = &hdr;
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sg_init_one(&buf, pkt->buf, buf_len);
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sgs[1] = &buf;
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ret = virtqueue_add_sgs(vq, sgs, 0, 2, pkt, GFP_KERNEL);
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if (ret)
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goto err;
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vsock->rx_buf_nr++;
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} while (vq->num_free);
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if (vsock->rx_buf_nr > vsock->rx_buf_max_nr)
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vsock->rx_buf_max_nr = vsock->rx_buf_nr;
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out:
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virtqueue_kick(vq);
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return;
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err:
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virtqueue_kick(vq);
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virtio_transport_free_pkt(pkt);
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return;
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}
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static void virtio_transport_send_pkt_work(struct work_struct *work)
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{
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struct virtio_vsock *vsock =
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container_of(work, struct virtio_vsock, tx_work);
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struct virtio_vsock_pkt *pkt;
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bool added = false;
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struct virtqueue *vq;
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unsigned int len;
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struct sock *sk;
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vq = vsock->vqs[VSOCK_VQ_TX];
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mutex_lock(&vsock->tx_lock);
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do {
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virtqueue_disable_cb(vq);
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while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
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sk = &pkt->trans->vsk->sk;
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virtio_transport_dec_tx_pkt(pkt);
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/* Release refcnt taken in virtio_transport_send_pkt */
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sock_put(sk);
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vsock->total_tx_buf -= pkt->len;
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virtio_transport_free_pkt(pkt);
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added = true;
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}
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} while (!virtqueue_enable_cb(vq));
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mutex_unlock(&vsock->tx_lock);
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if (added)
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wake_up(&vsock->queue_wait);
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}
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static void virtio_transport_recv_pkt_work(struct work_struct *work)
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{
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struct virtio_vsock *vsock =
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container_of(work, struct virtio_vsock, rx_work);
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struct virtio_vsock_pkt *pkt;
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struct virtqueue *vq;
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unsigned int len;
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vq = vsock->vqs[VSOCK_VQ_RX];
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mutex_lock(&vsock->rx_lock);
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do {
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virtqueue_disable_cb(vq);
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while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) {
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pkt->len = len;
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virtio_transport_recv_pkt(pkt);
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vsock->rx_buf_nr--;
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}
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} while (!virtqueue_enable_cb(vq));
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if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2)
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virtio_vsock_rx_fill(vsock);
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mutex_unlock(&vsock->rx_lock);
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}
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static void virtio_vsock_ctrl_done(struct virtqueue *vq)
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{
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}
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static void virtio_vsock_tx_done(struct virtqueue *vq)
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{
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struct virtio_vsock *vsock = vq->vdev->priv;
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if (!vsock)
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return;
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queue_work(virtio_vsock_workqueue, &vsock->tx_work);
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}
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static void virtio_vsock_rx_done(struct virtqueue *vq)
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{
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struct virtio_vsock *vsock = vq->vdev->priv;
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if (!vsock)
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return;
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queue_work(virtio_vsock_workqueue, &vsock->rx_work);
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}
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static int
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virtio_transport_socket_init(struct vsock_sock *vsk, struct vsock_sock *psk)
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{
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struct virtio_transport *trans;
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int ret;
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ret = virtio_transport_do_socket_init(vsk, psk);
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if (ret)
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return ret;
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trans = vsk->trans;
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trans->ops = &virtio_ops;
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return ret;
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}
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static struct vsock_transport virtio_transport = {
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.get_local_cid = virtio_transport_get_local_cid,
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.init = virtio_transport_socket_init,
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.destruct = virtio_transport_destruct,
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.release = virtio_transport_release,
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.connect = virtio_transport_connect,
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.shutdown = virtio_transport_shutdown,
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.dgram_bind = virtio_transport_dgram_bind,
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.dgram_dequeue = virtio_transport_dgram_dequeue,
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.dgram_enqueue = virtio_transport_dgram_enqueue,
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.dgram_allow = virtio_transport_dgram_allow,
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.stream_dequeue = virtio_transport_stream_dequeue,
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.stream_enqueue = virtio_transport_stream_enqueue,
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.stream_has_data = virtio_transport_stream_has_data,
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.stream_has_space = virtio_transport_stream_has_space,
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.stream_rcvhiwat = virtio_transport_stream_rcvhiwat,
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.stream_is_active = virtio_transport_stream_is_active,
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.stream_allow = virtio_transport_stream_allow,
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.notify_poll_in = virtio_transport_notify_poll_in,
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.notify_poll_out = virtio_transport_notify_poll_out,
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.notify_recv_init = virtio_transport_notify_recv_init,
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.notify_recv_pre_block = virtio_transport_notify_recv_pre_block,
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.notify_recv_pre_dequeue = virtio_transport_notify_recv_pre_dequeue,
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.notify_recv_post_dequeue = virtio_transport_notify_recv_post_dequeue,
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.notify_send_init = virtio_transport_notify_send_init,
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.notify_send_pre_block = virtio_transport_notify_send_pre_block,
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.notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue,
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.notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue,
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.set_buffer_size = virtio_transport_set_buffer_size,
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.set_min_buffer_size = virtio_transport_set_min_buffer_size,
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.set_max_buffer_size = virtio_transport_set_max_buffer_size,
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.get_buffer_size = virtio_transport_get_buffer_size,
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.get_min_buffer_size = virtio_transport_get_min_buffer_size,
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.get_max_buffer_size = virtio_transport_get_max_buffer_size,
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};
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static int virtio_vsock_probe(struct virtio_device *vdev)
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{
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vq_callback_t *callbacks[] = {
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virtio_vsock_ctrl_done,
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virtio_vsock_rx_done,
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virtio_vsock_tx_done,
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};
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const char *names[] = {
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"ctrl",
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"rx",
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"tx",
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};
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struct virtio_vsock *vsock = NULL;
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u32 guest_cid;
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int ret;
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ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
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if (ret)
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return ret;
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/* Only one virtio-vsock device per guest is supported */
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if (the_virtio_vsock) {
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ret = -EBUSY;
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||||
goto out;
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||||
}
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||||
vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
|
||||
if (!vsock) {
|
||||
ret = -ENOMEM;
|
||||
goto out;
|
||||
}
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||||
|
||||
vsock->vdev = vdev;
|
||||
|
||||
ret = vsock->vdev->config->find_vqs(vsock->vdev, VSOCK_VQ_MAX,
|
||||
vsock->vqs, callbacks, names);
|
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if (ret < 0)
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goto out;
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||||
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||||
vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
|
||||
&guest_cid, sizeof(guest_cid));
|
||||
vsock->guest_cid = le32_to_cpu(guest_cid);
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||||
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;
|
||||
|
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vdev->priv = the_virtio_vsock = vsock;
|
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init_waitqueue_head(&vsock->queue_wait);
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||||
mutex_init(&vsock->tx_lock);
|
||||
mutex_init(&vsock->rx_lock);
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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);
|
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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);
|
||||
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Ссылка в новой задаче