diff options
Diffstat (limited to 'drivers/vhost/vsock.c')
| -rw-r--r-- | drivers/vhost/vsock.c | 948 |
1 files changed, 948 insertions, 0 deletions
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c new file mode 100644 index 000000000..1f3b89c88 --- /dev/null +++ b/drivers/vhost/vsock.c @@ -0,0 +1,948 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * vhost transport for vsock + * + * Copyright (C) 2013-2015 Red Hat, Inc. + * Author: Asias He <asias@redhat.com> + * Stefan Hajnoczi <stefanha@redhat.com> + */ +#include <linux/miscdevice.h> +#include <linux/atomic.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/vmalloc.h> +#include <net/sock.h> +#include <linux/virtio_vsock.h> +#include <linux/vhost.h> +#include <linux/hashtable.h> + +#include <net/af_vsock.h> +#include "vhost.h" + +#define VHOST_VSOCK_DEFAULT_HOST_CID 2 +/* Max number of bytes transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others. */ +#define VHOST_VSOCK_WEIGHT 0x80000 +/* Max number of packets transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others with + * small pkts. + */ +#define VHOST_VSOCK_PKT_WEIGHT 256 + +enum { + VHOST_VSOCK_FEATURES = VHOST_FEATURES | + (1ULL << VIRTIO_F_ACCESS_PLATFORM) | + (1ULL << VIRTIO_VSOCK_F_SEQPACKET) +}; + +enum { + VHOST_VSOCK_BACKEND_FEATURES = (1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2) +}; + +/* Used to track all the vhost_vsock instances on the system. */ +static DEFINE_MUTEX(vhost_vsock_mutex); +static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8); + +struct vhost_vsock { + struct vhost_dev dev; + struct vhost_virtqueue vqs[2]; + + /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */ + struct hlist_node hash; + + struct vhost_work send_pkt_work; + struct sk_buff_head send_pkt_queue; /* host->guest pending packets */ + + atomic_t queued_replies; + + u32 guest_cid; + bool seqpacket_allow; +}; + +static u32 vhost_transport_get_local_cid(void) +{ + return VHOST_VSOCK_DEFAULT_HOST_CID; +} + +/* Callers that dereference the return value must hold vhost_vsock_mutex or the + * RCU read lock. + */ +static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) +{ + struct vhost_vsock *vsock; + + hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) { + u32 other_cid = vsock->guest_cid; + + /* Skip instances that have no CID yet */ + if (other_cid == 0) + continue; + + if (other_cid == guest_cid) + return vsock; + + } + + return NULL; +} + +static void +vhost_transport_do_send_pkt(struct vhost_vsock *vsock, + struct vhost_virtqueue *vq) +{ + struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; + int pkts = 0, total_len = 0; + bool added = false; + bool restart_tx = false; + + mutex_lock(&vq->mutex); + + if (!vhost_vq_get_backend(vq)) + goto out; + + if (!vq_meta_prefetch(vq)) + goto out; + + /* Avoid further vmexits, we're already processing the virtqueue */ + vhost_disable_notify(&vsock->dev, vq); + + do { + struct virtio_vsock_hdr *hdr; + size_t iov_len, payload_len; + struct iov_iter iov_iter; + u32 flags_to_restore = 0; + struct sk_buff *skb; + unsigned out, in; + size_t nbytes; + int head; + + skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue); + + if (!skb) { + vhost_enable_notify(&vsock->dev, vq); + break; + } + + head = vhost_get_vq_desc(vq, vq->iov, ARRAY_SIZE(vq->iov), + &out, &in, NULL, NULL); + if (head < 0) { + virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); + break; + } + + if (head == vq->num) { + virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); + /* We cannot finish yet if more buffers snuck in while + * re-enabling notify. + */ + if (unlikely(vhost_enable_notify(&vsock->dev, vq))) { + vhost_disable_notify(&vsock->dev, vq); + continue; + } + break; + } + + if (out) { + kfree_skb(skb); + vq_err(vq, "Expected 0 output buffers, got %u\n", out); + break; + } + + iov_len = iov_length(&vq->iov[out], in); + if (iov_len < sizeof(*hdr)) { + kfree_skb(skb); + vq_err(vq, "Buffer len [%zu] too small\n", iov_len); + break; + } + + iov_iter_init(&iov_iter, ITER_DEST, &vq->iov[out], in, iov_len); + payload_len = skb->len; + hdr = virtio_vsock_hdr(skb); + + /* If the packet is greater than the space available in the + * buffer, we split it using multiple buffers. + */ + if (payload_len > iov_len - sizeof(*hdr)) { + payload_len = iov_len - sizeof(*hdr); + + /* As we are copying pieces of large packet's buffer to + * small rx buffers, headers of packets in rx queue are + * created dynamically and are initialized with header + * of current packet(except length). But in case of + * SOCK_SEQPACKET, we also must clear message delimeter + * bit (VIRTIO_VSOCK_SEQ_EOM) and MSG_EOR bit + * (VIRTIO_VSOCK_SEQ_EOR) if set. Otherwise, + * there will be sequence of packets with these + * bits set. After initialized header will be copied to + * rx buffer, these required bits will be restored. + */ + if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) { + hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM); + flags_to_restore |= VIRTIO_VSOCK_SEQ_EOM; + + if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR) { + hdr->flags &= ~cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR); + flags_to_restore |= VIRTIO_VSOCK_SEQ_EOR; + } + } + } + + /* Set the correct length in the header */ + hdr->len = cpu_to_le32(payload_len); + + nbytes = copy_to_iter(hdr, sizeof(*hdr), &iov_iter); + if (nbytes != sizeof(*hdr)) { + kfree_skb(skb); + vq_err(vq, "Faulted on copying pkt hdr\n"); + break; + } + + nbytes = copy_to_iter(skb->data, payload_len, &iov_iter); + if (nbytes != payload_len) { + kfree_skb(skb); + vq_err(vq, "Faulted on copying pkt buf\n"); + break; + } + + /* Deliver to monitoring devices all packets that we + * will transmit. + */ + virtio_transport_deliver_tap_pkt(skb); + + vhost_add_used(vq, head, sizeof(*hdr) + payload_len); + added = true; + + skb_pull(skb, payload_len); + total_len += payload_len; + + /* If we didn't send all the payload we can requeue the packet + * to send it with the next available buffer. + */ + if (skb->len > 0) { + hdr->flags |= cpu_to_le32(flags_to_restore); + + /* We are queueing the same skb to handle + * the remaining bytes, and we want to deliver it + * to monitoring devices in the next iteration. + */ + virtio_vsock_skb_clear_tap_delivered(skb); + virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); + } else { + if (virtio_vsock_skb_reply(skb)) { + int val; + + val = atomic_dec_return(&vsock->queued_replies); + + /* Do we have resources to resume tx + * processing? + */ + if (val + 1 == tx_vq->num) + restart_tx = true; + } + + consume_skb(skb); + } + } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); + if (added) + vhost_signal(&vsock->dev, vq); + +out: + mutex_unlock(&vq->mutex); + + if (restart_tx) + vhost_poll_queue(&tx_vq->poll); +} + +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]; + + vhost_transport_do_send_pkt(vsock, vq); +} + +static int +vhost_transport_send_pkt(struct sk_buff *skb) +{ + struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); + struct vhost_vsock *vsock; + int len = skb->len; + + rcu_read_lock(); + + /* Find the vhost_vsock according to guest context id */ + vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid)); + if (!vsock) { + rcu_read_unlock(); + kfree_skb(skb); + return -ENODEV; + } + + if (virtio_vsock_skb_reply(skb)) + atomic_inc(&vsock->queued_replies); + + virtio_vsock_skb_queue_tail(&vsock->send_pkt_queue, skb); + vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + + rcu_read_unlock(); + return len; +} + +static int +vhost_transport_cancel_pkt(struct vsock_sock *vsk) +{ + struct vhost_vsock *vsock; + int cnt = 0; + int ret = -ENODEV; + + rcu_read_lock(); + + /* Find the vhost_vsock according to guest context id */ + vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); + if (!vsock) + goto out; + + cnt = virtio_transport_purge_skbs(vsk, &vsock->send_pkt_queue); + + if (cnt) { + struct vhost_virtqueue *tx_vq = &vsock->vqs[VSOCK_VQ_TX]; + int new_cnt; + + new_cnt = atomic_sub_return(cnt, &vsock->queued_replies); + if (new_cnt + cnt >= tx_vq->num && new_cnt < tx_vq->num) + vhost_poll_queue(&tx_vq->poll); + } + + ret = 0; +out: + rcu_read_unlock(); + return ret; +} + +static struct sk_buff * +vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, + unsigned int out, unsigned int in) +{ + struct virtio_vsock_hdr *hdr; + struct iov_iter iov_iter; + struct sk_buff *skb; + size_t payload_len; + size_t nbytes; + size_t len; + + if (in != 0) { + vq_err(vq, "Expected 0 input buffers, got %u\n", in); + return NULL; + } + + len = iov_length(vq->iov, out); + + /* len contains both payload and hdr */ + skb = virtio_vsock_alloc_skb(len, GFP_KERNEL); + if (!skb) + return NULL; + + iov_iter_init(&iov_iter, ITER_SOURCE, vq->iov, out, len); + + hdr = virtio_vsock_hdr(skb); + nbytes = copy_from_iter(hdr, sizeof(*hdr), &iov_iter); + if (nbytes != sizeof(*hdr)) { + vq_err(vq, "Expected %zu bytes for pkt->hdr, got %zu bytes\n", + sizeof(*hdr), nbytes); + kfree_skb(skb); + return NULL; + } + + payload_len = le32_to_cpu(hdr->len); + + /* No payload */ + if (!payload_len) + return skb; + + /* The pkt is too big or the length in the header is invalid */ + if (payload_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || + payload_len + sizeof(*hdr) > len) { + kfree_skb(skb); + return NULL; + } + + virtio_vsock_skb_rx_put(skb); + + nbytes = copy_from_iter(skb->data, payload_len, &iov_iter); + if (nbytes != payload_len) { + vq_err(vq, "Expected %zu byte payload, got %zu bytes\n", + payload_len, nbytes); + kfree_skb(skb); + return NULL; + } + + return skb; +} + +/* Is there space left for replies to rx packets? */ +static bool vhost_vsock_more_replies(struct vhost_vsock *vsock) +{ + struct vhost_virtqueue *vq = &vsock->vqs[VSOCK_VQ_TX]; + int val; + + smp_rmb(); /* paired with atomic_inc() and atomic_dec_return() */ + val = atomic_read(&vsock->queued_replies); + + return val < vq->num; +} + +static bool vhost_transport_seqpacket_allow(u32 remote_cid); + +static struct virtio_transport vhost_transport = { + .transport = { + .module = THIS_MODULE, + + .get_local_cid = vhost_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, + .cancel_pkt = vhost_transport_cancel_pkt, + + .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, + + .seqpacket_dequeue = virtio_transport_seqpacket_dequeue, + .seqpacket_enqueue = virtio_transport_seqpacket_enqueue, + .seqpacket_allow = vhost_transport_seqpacket_allow, + .seqpacket_has_data = virtio_transport_seqpacket_has_data, + + .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, + .notify_buffer_size = virtio_transport_notify_buffer_size, + + }, + + .send_pkt = vhost_transport_send_pkt, +}; + +static bool vhost_transport_seqpacket_allow(u32 remote_cid) +{ + struct vhost_vsock *vsock; + bool seqpacket_allow = false; + + rcu_read_lock(); + vsock = vhost_vsock_get(remote_cid); + + if (vsock) + seqpacket_allow = vsock->seqpacket_allow; + + rcu_read_unlock(); + + return seqpacket_allow; +} + +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); + int head, pkts = 0, total_len = 0; + unsigned int out, in; + struct sk_buff *skb; + bool added = false; + + mutex_lock(&vq->mutex); + + if (!vhost_vq_get_backend(vq)) + goto out; + + if (!vq_meta_prefetch(vq)) + goto out; + + vhost_disable_notify(&vsock->dev, vq); + do { + struct virtio_vsock_hdr *hdr; + + if (!vhost_vsock_more_replies(vsock)) { + /* Stop tx until the device processes already + * pending replies. Leave tx virtqueue + * callbacks disabled. + */ + goto no_more_replies; + } + + head = vhost_get_vq_desc(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; + } + + skb = vhost_vsock_alloc_skb(vq, out, in); + if (!skb) { + vq_err(vq, "Faulted on pkt\n"); + continue; + } + + total_len += sizeof(*hdr) + skb->len; + + /* Deliver to monitoring devices all received packets */ + virtio_transport_deliver_tap_pkt(skb); + + hdr = virtio_vsock_hdr(skb); + + /* Only accept correctly addressed packets */ + if (le64_to_cpu(hdr->src_cid) == vsock->guest_cid && + le64_to_cpu(hdr->dst_cid) == + vhost_transport_get_local_cid()) + virtio_transport_recv_pkt(&vhost_transport, skb); + else + kfree_skb(skb); + + vhost_add_used(vq, head, 0); + added = true; + } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); + +no_more_replies: + if (added) + vhost_signal(&vsock->dev, vq); + +out: + 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_start(struct vhost_vsock *vsock) +{ + struct vhost_virtqueue *vq; + size_t i; + int ret; + + mutex_lock(&vsock->dev.mutex); + + ret = vhost_dev_check_owner(&vsock->dev); + if (ret) + goto err; + + for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { + vq = &vsock->vqs[i]; + + mutex_lock(&vq->mutex); + + if (!vhost_vq_access_ok(vq)) { + ret = -EFAULT; + goto err_vq; + } + + if (!vhost_vq_get_backend(vq)) { + vhost_vq_set_backend(vq, vsock); + ret = vhost_vq_init_access(vq); + if (ret) + goto err_vq; + } + + mutex_unlock(&vq->mutex); + } + + /* Some packets may have been queued before the device was started, + * let's kick the send worker to send them. + */ + vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + + mutex_unlock(&vsock->dev.mutex); + return 0; + +err_vq: + vhost_vq_set_backend(vq, NULL); + mutex_unlock(&vq->mutex); + + for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { + vq = &vsock->vqs[i]; + + mutex_lock(&vq->mutex); + vhost_vq_set_backend(vq, NULL); + mutex_unlock(&vq->mutex); + } +err: + mutex_unlock(&vsock->dev.mutex); + return ret; +} + +static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner) +{ + size_t i; + int ret = 0; + + mutex_lock(&vsock->dev.mutex); + + if (check_owner) { + ret = vhost_dev_check_owner(&vsock->dev); + if (ret) + goto err; + } + + for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { + struct vhost_virtqueue *vq = &vsock->vqs[i]; + + mutex_lock(&vq->mutex); + vhost_vq_set_backend(vq, NULL); + mutex_unlock(&vq->mutex); + } + +err: + mutex_unlock(&vsock->dev.mutex); + return ret; +} + +static void vhost_vsock_free(struct vhost_vsock *vsock) +{ + kvfree(vsock); +} + +static int vhost_vsock_dev_open(struct inode *inode, struct file *file) +{ + struct vhost_virtqueue **vqs; + struct vhost_vsock *vsock; + int ret; + + /* This struct is large and allocation could fail, fall back to vmalloc + * if there is no other way. + */ + vsock = kvmalloc(sizeof(*vsock), GFP_KERNEL | __GFP_RETRY_MAYFAIL); + if (!vsock) + return -ENOMEM; + + vqs = kmalloc_array(ARRAY_SIZE(vsock->vqs), sizeof(*vqs), GFP_KERNEL); + if (!vqs) { + ret = -ENOMEM; + goto out; + } + + vsock->guest_cid = 0; /* no CID assigned yet */ + + atomic_set(&vsock->queued_replies, 0); + + vqs[VSOCK_VQ_TX] = &vsock->vqs[VSOCK_VQ_TX]; + vqs[VSOCK_VQ_RX] = &vsock->vqs[VSOCK_VQ_RX]; + vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; + vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; + + vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), + UIO_MAXIOV, VHOST_VSOCK_PKT_WEIGHT, + VHOST_VSOCK_WEIGHT, true, NULL); + + file->private_data = vsock; + skb_queue_head_init(&vsock->send_pkt_queue); + vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); + return 0; + +out: + vhost_vsock_free(vsock); + return ret; +} + +static void vhost_vsock_flush(struct vhost_vsock *vsock) +{ + vhost_dev_flush(&vsock->dev); +} + +static void vhost_vsock_reset_orphans(struct sock *sk) +{ + struct vsock_sock *vsk = vsock_sk(sk); + + /* vmci_transport.c doesn't take sk_lock here either. At least we're + * under vsock_table_lock so the sock cannot disappear while we're + * executing. + */ + + /* If the peer is still valid, no need to reset connection */ + if (vhost_vsock_get(vsk->remote_addr.svm_cid)) + return; + + /* If the close timeout is pending, let it expire. This avoids races + * with the timeout callback. + */ + if (vsk->close_work_scheduled) + return; + + sock_set_flag(sk, SOCK_DONE); + vsk->peer_shutdown = SHUTDOWN_MASK; + sk->sk_state = SS_UNCONNECTED; + sk->sk_err = ECONNRESET; + sk_error_report(sk); +} + +static int vhost_vsock_dev_release(struct inode *inode, struct file *file) +{ + struct vhost_vsock *vsock = file->private_data; + + mutex_lock(&vhost_vsock_mutex); + if (vsock->guest_cid) + hash_del_rcu(&vsock->hash); + mutex_unlock(&vhost_vsock_mutex); + + /* Wait for other CPUs to finish using vsock */ + synchronize_rcu(); + + /* Iterating over all connections for all CIDs to find orphans is + * inefficient. Room for improvement here. */ + vsock_for_each_connected_socket(&vhost_transport.transport, + vhost_vsock_reset_orphans); + + /* Don't check the owner, because we are in the release path, so we + * need to stop the vsock device in any case. + * vhost_vsock_stop() can not fail in this case, so we don't need to + * check the return code. + */ + vhost_vsock_stop(vsock, false); + vhost_vsock_flush(vsock); + vhost_dev_stop(&vsock->dev); + + virtio_vsock_skb_queue_purge(&vsock->send_pkt_queue); + + vhost_dev_cleanup(&vsock->dev); + kfree(vsock->dev.vqs); + vhost_vsock_free(vsock); + return 0; +} + +static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid) +{ + struct vhost_vsock *other; + + /* Refuse reserved CIDs */ + if (guest_cid <= VMADDR_CID_HOST || + guest_cid == U32_MAX) + return -EINVAL; + + /* 64-bit CIDs are not yet supported */ + if (guest_cid > U32_MAX) + return -EINVAL; + + /* Refuse if CID is assigned to the guest->host transport (i.e. nested + * VM), to make the loopback work. + */ + if (vsock_find_cid(guest_cid)) + return -EADDRINUSE; + + /* Refuse if CID is already in use */ + mutex_lock(&vhost_vsock_mutex); + other = vhost_vsock_get(guest_cid); + if (other && other != vsock) { + mutex_unlock(&vhost_vsock_mutex); + return -EADDRINUSE; + } + + if (vsock->guest_cid) + hash_del_rcu(&vsock->hash); + + vsock->guest_cid = guest_cid; + hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid); + mutex_unlock(&vhost_vsock_mutex); + + return 0; +} + +static int vhost_vsock_set_features(struct vhost_vsock *vsock, u64 features) +{ + struct vhost_virtqueue *vq; + int i; + + if (features & ~VHOST_VSOCK_FEATURES) + return -EOPNOTSUPP; + + mutex_lock(&vsock->dev.mutex); + if ((features & (1 << VHOST_F_LOG_ALL)) && + !vhost_log_access_ok(&vsock->dev)) { + goto err; + } + + if ((features & (1ULL << VIRTIO_F_ACCESS_PLATFORM))) { + if (vhost_init_device_iotlb(&vsock->dev, true)) + goto err; + } + + if (features & (1ULL << VIRTIO_VSOCK_F_SEQPACKET)) + vsock->seqpacket_allow = true; + + for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { + vq = &vsock->vqs[i]; + mutex_lock(&vq->mutex); + vq->acked_features = features; + mutex_unlock(&vq->mutex); + } + mutex_unlock(&vsock->dev.mutex); + return 0; + +err: + mutex_unlock(&vsock->dev.mutex); + return -EFAULT; +} + +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 guest_cid; + u64 features; + int start; + int r; + + switch (ioctl) { + case VHOST_VSOCK_SET_GUEST_CID: + if (copy_from_user(&guest_cid, argp, sizeof(guest_cid))) + return -EFAULT; + return vhost_vsock_set_cid(vsock, guest_cid); + case VHOST_VSOCK_SET_RUNNING: + if (copy_from_user(&start, argp, sizeof(start))) + return -EFAULT; + if (start) + return vhost_vsock_start(vsock); + else + return vhost_vsock_stop(vsock, true); + case VHOST_GET_FEATURES: + features = VHOST_VSOCK_FEATURES; + if (copy_to_user(argp, &features, sizeof(features))) + return -EFAULT; + return 0; + case VHOST_SET_FEATURES: + if (copy_from_user(&features, argp, sizeof(features))) + return -EFAULT; + return vhost_vsock_set_features(vsock, features); + case VHOST_GET_BACKEND_FEATURES: + features = VHOST_VSOCK_BACKEND_FEATURES; + if (copy_to_user(argp, &features, sizeof(features))) + return -EFAULT; + return 0; + case VHOST_SET_BACKEND_FEATURES: + if (copy_from_user(&features, argp, sizeof(features))) + return -EFAULT; + if (features & ~VHOST_VSOCK_BACKEND_FEATURES) + return -EOPNOTSUPP; + vhost_set_backend_features(&vsock->dev, features); + 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 ssize_t vhost_vsock_chr_read_iter(struct kiocb *iocb, struct iov_iter *to) +{ + struct file *file = iocb->ki_filp; + struct vhost_vsock *vsock = file->private_data; + struct vhost_dev *dev = &vsock->dev; + int noblock = file->f_flags & O_NONBLOCK; + + return vhost_chr_read_iter(dev, to, noblock); +} + +static ssize_t vhost_vsock_chr_write_iter(struct kiocb *iocb, + struct iov_iter *from) +{ + struct file *file = iocb->ki_filp; + struct vhost_vsock *vsock = file->private_data; + struct vhost_dev *dev = &vsock->dev; + + return vhost_chr_write_iter(dev, from); +} + +static __poll_t vhost_vsock_chr_poll(struct file *file, poll_table *wait) +{ + struct vhost_vsock *vsock = file->private_data; + struct vhost_dev *dev = &vsock->dev; + + return vhost_chr_poll(file, dev, wait); +} + +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, + .compat_ioctl = compat_ptr_ioctl, + .read_iter = vhost_vsock_chr_read_iter, + .write_iter = vhost_vsock_chr_write_iter, + .poll = vhost_vsock_chr_poll, +}; + +static struct miscdevice vhost_vsock_misc = { + .minor = VHOST_VSOCK_MINOR, + .name = "vhost-vsock", + .fops = &vhost_vsock_fops, +}; + +static int __init vhost_vsock_init(void) +{ + int ret; + + ret = vsock_core_register(&vhost_transport.transport, + VSOCK_TRANSPORT_F_H2G); + if (ret < 0) + return ret; + + ret = misc_register(&vhost_vsock_misc); + if (ret) { + vsock_core_unregister(&vhost_transport.transport); + return ret; + } + + return 0; +}; + +static void __exit vhost_vsock_exit(void) +{ + misc_deregister(&vhost_vsock_misc); + vsock_core_unregister(&vhost_transport.transport); +}; + +module_init(vhost_vsock_init); +module_exit(vhost_vsock_exit); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Asias He"); +MODULE_DESCRIPTION("vhost transport for vsock "); +MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR); +MODULE_ALIAS("devname:vhost-vsock"); |