From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: [RFC v4 3/5] VSOCK: Introduce virtio_transport.ko Date: Tue, 22 Dec 2015 17:07:36 +0800 Message-ID: <1450775258-18287-4-git-send-email-stefanha@redhat.com> References: <1450775258-18287-1-git-send-email-stefanha@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Stefan Hajnoczi , "Michael S. Tsirkin" , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, Matt Benjamin , Asias He , Christoffer Dall , matt.ma@linaro.org To: kvm@vger.kernel.org Return-path: In-Reply-To: <1450775258-18287-1-git-send-email-stefanha@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org From: Asias He VM sockets virtio transport implementation. This driver runs in the guest. Signed-off-by: Asias He Signed-off-by: Stefan Hajnoczi --- v4: * Add MAINTAINERS file entry * Drop short/long rx packets * checkpatch.pl cleanups * Clarify locking in struct virtio_vsock * Narrow local variable scopes as suggested by Alex Bennee * Call wake_up() after decrementing total_tx_buf to avoid deadlock v2: * Fix total_tx_buf accounting * Add virtio_transport global mutex to prevent races Signed-off-by: Stefan Hajnoczi --- MAINTAINERS | 1 + net/vmw_vsock/virtio_transport.c | 481 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 482 insertions(+) create mode 100644 net/vmw_vsock/virtio_transport.c diff --git a/MAINTAINERS b/MAINTAINERS index d42db78..67d8504 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11369,6 +11369,7 @@ S: Maintained F: include/linux/virtio_vsock.h F: include/uapi/linux/virtio_vsock.h F: net/vmw_vsock/virtio_transport_common.c +F: net/vmw_vsock/virtio_transport.c VIRTUAL SERIO DEVICE DRIVER M: Stephen Chandler Paul diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c new file mode 100644 index 0000000..e4787bf --- /dev/null +++ b/net/vmw_vsock/virtio_transport.c @@ -0,0 +1,481 @@ +/* + * virtio transport for vsock + * + * Copyright (C) 2013-2015 Red Hat, Inc. + * Author: Asias He + * Stefan Hajnoczi + * + * Some of the code is take from Gerd Hoffmann 's + * early virtio-vsock proof-of-concept bits. + * + * This work is licensed under the terms of the GNU GPL, version 2. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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 { + struct virtio_device *vdev; + struct virtqueue *vqs[VSOCK_VQ_MAX]; + + /* Virtqueue processing is deferred to a workqueue */ + struct work_struct tx_work; + struct work_struct rx_work; + + wait_queue_head_t tx_wait; /* for waiting for tx resources */ + + /* The following fields are protected by tx_lock. vqs[VSOCK_VQ_TX] + * must be accessed with tx_lock held. + */ + struct mutex tx_lock; + u32 total_tx_buf; + + /* The following fields are protected by rx_lock. vqs[VSOCK_VQ_RX] + * must be accessed with rx_lock held. + */ + struct mutex rx_lock; + int rx_buf_nr; + int rx_buf_max_nr; + + 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_one_pkt(struct virtio_vsock *vsock, + struct virtio_vsock_pkt *pkt) +{ + struct scatterlist hdr, buf, *sgs[2]; + int ret, in_sg = 0, out_sg = 0; + struct virtqueue *vq; + DEFINE_WAIT(wait); + + vq = vsock->vqs[VSOCK_VQ_TX]; + + /* Put pkt in the virtqueue */ + 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; + } + + 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->tx_wait, &wait, + TASK_UNINTERRUPTIBLE); + mutex_unlock(&vsock->tx_lock); + schedule(); + mutex_lock(&vsock->tx_lock); + finish_wait(&vsock->tx_wait, &wait); + } + virtqueue_kick(vq); + mutex_unlock(&vsock->tx_lock); + + return pkt->len; +} + +static int +virtio_transport_send_pkt_no_sock(struct virtio_vsock_pkt *pkt) +{ + struct virtio_vsock *vsock; + + vsock = virtio_vsock_get(); + if (!vsock) { + virtio_transport_free_pkt(pkt); + return -ENODEV; + } + + return virtio_transport_send_one_pkt(vsock, pkt); +} + +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; + struct virtio_vsock_sock *vvs; + struct virtio_vsock_pkt *pkt; + struct virtio_vsock *vsock; + 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; + } + + vvs = vsk->trans; + + if (pkt_len > VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE) + pkt_len = VIRTIO_VSOCK_DEFAULT_RX_BUF_SIZE; + 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; + + /* 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->tx_wait, &wait, + TASK_UNINTERRUPTIBLE); + mutex_unlock(&vsock->tx_lock); + schedule(); + mutex_lock(&vsock->tx_lock); + finish_wait(&vsock->tx_wait, &wait); + } + vsock->total_tx_buf += pkt_len; + mutex_unlock(&vsock->tx_lock); + + pkt = virtio_transport_alloc_pkt(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(vvs, pkt_len); + wake_up(&vsock->tx_wait); + return -ENOMEM; + } + + virtio_transport_inc_tx_pkt(vvs, pkt); + + return virtio_transport_send_one_pkt(vsock, 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) + break; + + pkt->buf = kmalloc(buf_len, GFP_KERNEL); + if (!pkt->buf) { + virtio_transport_free_pkt(pkt); + break; + } + + pkt->len = buf_len; + + 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) { + virtio_transport_free_pkt(pkt); + break; + } + 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; + virtqueue_kick(vq); +} + +static void virtio_transport_send_pkt_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); + do { + struct virtio_vsock_pkt *pkt; + unsigned int len; + + virtqueue_disable_cb(vq); + while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { + 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->tx_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 virtqueue *vq; + + vq = vsock->vqs[VSOCK_VQ_RX]; + mutex_lock(&vsock->rx_lock); + do { + struct virtio_vsock_pkt *pkt; + unsigned int len; + + virtqueue_disable_cb(vq); + while ((pkt = virtqueue_get_buf(vq, &len)) != NULL) { + vsock->rx_buf_nr--; + + /* Drop short/long packets */ + if (unlikely(len < sizeof(pkt->hdr) || + len > sizeof(pkt->hdr) + pkt->len)) { + virtio_transport_free_pkt(pkt); + continue; + } + + pkt->len = len - sizeof(pkt->hdr); + virtio_transport_recv_pkt(pkt); + } + } 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 struct virtio_transport virtio_transport = { + .transport = { + .get_local_cid = virtio_transport_get_local_cid, + + .init = virtio_transport_do_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, + }, + + .send_pkt = virtio_transport_send_pkt, + .send_pkt_no_sock = virtio_transport_send_pkt_no_sock, +}; + +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, + }; + static const char * const 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); + + ret = vsock_core_init(&virtio_transport.transport); + if (ret < 0) + goto out_vqs; + + vsock->rx_buf_nr = 0; + vsock->rx_buf_max_nr = 0; + + vdev->priv = vsock; + the_virtio_vsock = vsock; + init_waitqueue_head(&vsock->tx_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; + + flush_work(&vsock->rx_work); + flush_work(&vsock->tx_work); + + vdev->config->reset(vdev); + + mutex_lock(&the_virtio_vsock_mutex); + the_virtio_vsock = NULL; + vsock_core_exit(); + mutex_unlock(&the_virtio_vsock_mutex); + + vdev->config->del_vqs(vdev); + + 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