diff options
Diffstat (limited to 'drivers/vhost/vsock.c')
| -rw-r--r-- | drivers/vhost/vsock.c | 74 |
1 files changed, 51 insertions, 23 deletions
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 0ec970ca64ce..3cefd602b5b1 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -15,6 +15,7 @@ #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" @@ -27,14 +28,14 @@ enum { /* Used to track all the vhost_vsock instances on the system. */ static DEFINE_SPINLOCK(vhost_vsock_lock); -static LIST_HEAD(vhost_vsock_list); +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_list, protected by vhost_vsock_lock */ - struct list_head list; + /* Link to global vhost_vsock_hash, writes use vhost_vsock_lock */ + struct hlist_node hash; struct vhost_work send_pkt_work; spinlock_t send_pkt_list_lock; @@ -50,12 +51,14 @@ static u32 vhost_transport_get_local_cid(void) return VHOST_VSOCK_DEFAULT_HOST_CID; } +/* Callers that dereference the return value must hold vhost_vsock_lock or the + * RCU read lock. + */ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) { struct vhost_vsock *vsock; - spin_lock_bh(&vhost_vsock_lock); - list_for_each_entry(vsock, &vhost_vsock_list, list) { + 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 */ @@ -63,11 +66,9 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) continue; if (other_cid == guest_cid) { - spin_unlock_bh(&vhost_vsock_lock); return vsock; } } - spin_unlock_bh(&vhost_vsock_lock); return NULL; } @@ -198,9 +199,12 @@ vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) struct vhost_virtqueue *vq; int len = pkt->len; + rcu_read_lock(); + /* Find the vhost_vsock according to guest context id */ vsock = vhost_vsock_get(le64_to_cpu(pkt->hdr.dst_cid)); if (!vsock) { + rcu_read_unlock(); virtio_transport_free_pkt(pkt); return -ENODEV; } @@ -215,6 +219,8 @@ vhost_transport_send_pkt(struct virtio_vsock_pkt *pkt) spin_unlock_bh(&vsock->send_pkt_list_lock); vhost_work_queue(&vsock->dev, &vsock->send_pkt_work); + + rcu_read_unlock(); return len; } @@ -224,12 +230,15 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) struct vhost_vsock *vsock; struct virtio_vsock_pkt *pkt, *n; int cnt = 0; + int ret = -ENODEV; LIST_HEAD(freeme); + rcu_read_lock(); + /* Find the vhost_vsock according to guest context id */ vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); if (!vsock) - return -ENODEV; + goto out; spin_lock_bh(&vsock->send_pkt_list_lock); list_for_each_entry_safe(pkt, n, &vsock->send_pkt_list, list) { @@ -255,7 +264,10 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) vhost_poll_queue(&tx_vq->poll); } - return 0; + ret = 0; +out: + rcu_read_unlock(); + return ret; } static struct virtio_vsock_pkt * @@ -508,6 +520,8 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) 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]; @@ -521,10 +535,6 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) spin_lock_init(&vsock->send_pkt_list_lock); INIT_LIST_HEAD(&vsock->send_pkt_list); vhost_work_init(&vsock->send_pkt_work, vhost_transport_send_pkt_work); - - spin_lock_bh(&vhost_vsock_lock); - list_add_tail(&vsock->list, &vhost_vsock_list); - spin_unlock_bh(&vhost_vsock_lock); return 0; out: @@ -551,13 +561,21 @@ static void vhost_vsock_reset_orphans(struct sock *sk) * executing. */ - if (!vhost_vsock_get(vsk->remote_addr.svm_cid)) { - sock_set_flag(sk, SOCK_DONE); - vsk->peer_shutdown = SHUTDOWN_MASK; - sk->sk_state = SS_UNCONNECTED; - sk->sk_err = ECONNRESET; - sk->sk_error_report(sk); - } + /* 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->sk_error_report(sk); } static int vhost_vsock_dev_release(struct inode *inode, struct file *file) @@ -565,9 +583,13 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) struct vhost_vsock *vsock = file->private_data; spin_lock_bh(&vhost_vsock_lock); - list_del(&vsock->list); + if (vsock->guest_cid) + hash_del_rcu(&vsock->hash); spin_unlock_bh(&vhost_vsock_lock); + /* 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_vsock_reset_orphans); @@ -607,12 +629,18 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid) return -EINVAL; /* Refuse if CID is already in use */ + spin_lock_bh(&vhost_vsock_lock); other = vhost_vsock_get(guest_cid); - if (other && other != vsock) + if (other && other != vsock) { + spin_unlock_bh(&vhost_vsock_lock); return -EADDRINUSE; + } + + if (vsock->guest_cid) + hash_del_rcu(&vsock->hash); - spin_lock_bh(&vhost_vsock_lock); vsock->guest_cid = guest_cid; + hash_add_rcu(vhost_vsock_hash, &vsock->hash, vsock->guest_cid); spin_unlock_bh(&vhost_vsock_lock); return 0; |