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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/vhost/vsock.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/vhost/vsock.c')
-rw-r--r--drivers/vhost/vsock.c948
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");