diff options
Diffstat (limited to 'net/vmw_vsock/virtio_transport.c')
-rw-r--r-- | net/vmw_vsock/virtio_transport.c | 265 |
1 files changed, 168 insertions, 97 deletions
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 96ab344f17bb..cc70d651d13e 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -39,6 +39,7 @@ struct virtio_vsock { * must be accessed with tx_lock held. */ struct mutex tx_lock; + bool tx_run; struct work_struct send_pkt_work; spinlock_t send_pkt_list_lock; @@ -54,6 +55,7 @@ struct virtio_vsock { * must be accessed with rx_lock held. */ struct mutex rx_lock; + bool rx_run; int rx_buf_nr; int rx_buf_max_nr; @@ -61,46 +63,28 @@ struct virtio_vsock { * vqs[VSOCK_VQ_EVENT] must be accessed with event_lock held. */ struct mutex event_lock; + bool event_run; struct virtio_vsock_event event_list[8]; 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(); - - if (!vsock) - return VMADDR_CID_ANY; - - return vsock->guest_cid; -} - -static void virtio_transport_loopback_work(struct work_struct *work) -{ - struct virtio_vsock *vsock = - container_of(work, struct virtio_vsock, loopback_work); - LIST_HEAD(pkts); - - spin_lock_bh(&vsock->loopback_list_lock); - list_splice_init(&vsock->loopback_list, &pkts); - spin_unlock_bh(&vsock->loopback_list_lock); - - mutex_lock(&vsock->rx_lock); - while (!list_empty(&pkts)) { - struct virtio_vsock_pkt *pkt; - - pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list); - list_del_init(&pkt->list); + struct virtio_vsock *vsock; + u32 ret; - virtio_transport_recv_pkt(pkt); + rcu_read_lock(); + vsock = rcu_dereference(the_virtio_vsock); + if (!vsock) { + ret = VMADDR_CID_ANY; + goto out_rcu; } - mutex_unlock(&vsock->rx_lock); + + ret = vsock->guest_cid; +out_rcu: + rcu_read_unlock(); + return ret; } static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock, @@ -128,6 +112,9 @@ virtio_transport_send_pkt_work(struct work_struct *work) mutex_lock(&vsock->tx_lock); + if (!vsock->tx_run) + goto out; + vq = vsock->vqs[VSOCK_VQ_TX]; for (;;) { @@ -186,6 +173,7 @@ virtio_transport_send_pkt_work(struct work_struct *work) if (added) virtqueue_kick(vq); +out: mutex_unlock(&vsock->tx_lock); if (restart_rx) @@ -198,14 +186,18 @@ virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt) struct virtio_vsock *vsock; int len = pkt->len; - vsock = virtio_vsock_get(); + rcu_read_lock(); + vsock = rcu_dereference(the_virtio_vsock); if (!vsock) { virtio_transport_free_pkt(pkt); - return -ENODEV; + len = -ENODEV; + goto out_rcu; } - if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) - return virtio_transport_send_pkt_loopback(vsock, pkt); + if (le64_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid) { + len = virtio_transport_send_pkt_loopback(vsock, pkt); + goto out_rcu; + } if (pkt->reply) atomic_inc(&vsock->queued_replies); @@ -215,6 +207,9 @@ virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt) spin_unlock_bh(&vsock->send_pkt_list_lock); queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work); + +out_rcu: + rcu_read_unlock(); return len; } @@ -223,12 +218,14 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk) { struct virtio_vsock *vsock; struct virtio_vsock_pkt *pkt, *n; - int cnt = 0; + int cnt = 0, ret; LIST_HEAD(freeme); - vsock = virtio_vsock_get(); + rcu_read_lock(); + vsock = rcu_dereference(the_virtio_vsock); if (!vsock) { - return -ENODEV; + ret = -ENODEV; + goto out_rcu; } spin_lock_bh(&vsock->send_pkt_list_lock); @@ -256,7 +253,11 @@ virtio_transport_cancel_pkt(struct vsock_sock *vsk) queue_work(virtio_vsock_workqueue, &vsock->rx_work); } - return 0; + ret = 0; + +out_rcu: + rcu_read_unlock(); + return ret; } static void virtio_vsock_rx_fill(struct virtio_vsock *vsock) @@ -308,6 +309,10 @@ static void virtio_transport_tx_work(struct work_struct *work) vq = vsock->vqs[VSOCK_VQ_TX]; mutex_lock(&vsock->tx_lock); + + if (!vsock->tx_run) + goto out; + do { struct virtio_vsock_pkt *pkt; unsigned int len; @@ -318,6 +323,8 @@ static void virtio_transport_tx_work(struct work_struct *work) added = true; } } while (!virtqueue_enable_cb(vq)); + +out: mutex_unlock(&vsock->tx_lock); if (added) @@ -336,56 +343,6 @@ static bool virtio_transport_more_replies(struct virtio_vsock *vsock) return val < virtqueue_get_vring_size(vq); } -static void virtio_transport_rx_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 { - virtqueue_disable_cb(vq); - for (;;) { - struct virtio_vsock_pkt *pkt; - unsigned int len; - - if (!virtio_transport_more_replies(vsock)) { - /* Stop rx until the device processes already - * pending replies. Leave rx virtqueue - * callbacks disabled. - */ - goto out; - } - - pkt = virtqueue_get_buf(vq, &len); - if (!pkt) { - break; - } - - 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_deliver_tap_pkt(pkt); - virtio_transport_recv_pkt(pkt); - } - } while (!virtqueue_enable_cb(vq)); - -out: - if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) - virtio_vsock_rx_fill(vsock); - mutex_unlock(&vsock->rx_lock); -} - /* event_lock must be held */ static int virtio_vsock_event_fill_one(struct virtio_vsock *vsock, struct virtio_vsock_event *event) @@ -455,6 +412,9 @@ static void virtio_transport_event_work(struct work_struct *work) mutex_lock(&vsock->event_lock); + if (!vsock->event_run) + goto out; + do { struct virtio_vsock_event *event; unsigned int len; @@ -469,7 +429,7 @@ static void virtio_transport_event_work(struct work_struct *work) } while (!virtqueue_enable_cb(vq)); virtqueue_kick(vsock->vqs[VSOCK_VQ_EVENT]); - +out: mutex_unlock(&vsock->event_lock); } @@ -546,6 +506,86 @@ static struct virtio_transport virtio_transport = { .send_pkt = virtio_transport_send_pkt, }; +static void virtio_transport_loopback_work(struct work_struct *work) +{ + struct virtio_vsock *vsock = + container_of(work, struct virtio_vsock, loopback_work); + LIST_HEAD(pkts); + + spin_lock_bh(&vsock->loopback_list_lock); + list_splice_init(&vsock->loopback_list, &pkts); + spin_unlock_bh(&vsock->loopback_list_lock); + + mutex_lock(&vsock->rx_lock); + + if (!vsock->rx_run) + goto out; + + while (!list_empty(&pkts)) { + struct virtio_vsock_pkt *pkt; + + pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list); + list_del_init(&pkt->list); + + virtio_transport_recv_pkt(&virtio_transport, pkt); + } +out: + mutex_unlock(&vsock->rx_lock); +} + +static void virtio_transport_rx_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); + + if (!vsock->rx_run) + goto out; + + do { + virtqueue_disable_cb(vq); + for (;;) { + struct virtio_vsock_pkt *pkt; + unsigned int len; + + if (!virtio_transport_more_replies(vsock)) { + /* Stop rx until the device processes already + * pending replies. Leave rx virtqueue + * callbacks disabled. + */ + goto out; + } + + pkt = virtqueue_get_buf(vq, &len); + if (!pkt) { + break; + } + + 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_deliver_tap_pkt(pkt); + virtio_transport_recv_pkt(&virtio_transport, pkt); + } + } while (!virtqueue_enable_cb(vq)); + +out: + if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) + virtio_vsock_rx_fill(vsock); + mutex_unlock(&vsock->rx_lock); +} + static int virtio_vsock_probe(struct virtio_device *vdev) { vq_callback_t *callbacks[] = { @@ -566,7 +606,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev) return ret; /* Only one virtio-vsock device per guest is supported */ - if (the_virtio_vsock) { + if (rcu_dereference_protected(the_virtio_vsock, + lockdep_is_held(&the_virtio_vsock_mutex))) { ret = -EBUSY; goto out; } @@ -591,8 +632,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev) vsock->rx_buf_max_nr = 0; atomic_set(&vsock->queued_replies, 0); - vdev->priv = vsock; - the_virtio_vsock = vsock; mutex_init(&vsock->tx_lock); mutex_init(&vsock->rx_lock); mutex_init(&vsock->event_lock); @@ -606,14 +645,23 @@ static int virtio_vsock_probe(struct virtio_device *vdev) INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work); INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work); + mutex_lock(&vsock->tx_lock); + vsock->tx_run = true; + mutex_unlock(&vsock->tx_lock); + mutex_lock(&vsock->rx_lock); virtio_vsock_rx_fill(vsock); + vsock->rx_run = true; mutex_unlock(&vsock->rx_lock); mutex_lock(&vsock->event_lock); virtio_vsock_event_fill(vsock); + vsock->event_run = true; mutex_unlock(&vsock->event_lock); + vdev->priv = vsock; + rcu_assign_pointer(the_virtio_vsock, vsock); + mutex_unlock(&the_virtio_vsock_mutex); return 0; @@ -628,6 +676,12 @@ static void virtio_vsock_remove(struct virtio_device *vdev) struct virtio_vsock *vsock = vdev->priv; struct virtio_vsock_pkt *pkt; + mutex_lock(&the_virtio_vsock_mutex); + + vdev->priv = NULL; + rcu_assign_pointer(the_virtio_vsock, NULL); + synchronize_rcu(); + flush_work(&vsock->loopback_work); flush_work(&vsock->rx_work); flush_work(&vsock->tx_work); @@ -637,6 +691,24 @@ static void virtio_vsock_remove(struct virtio_device *vdev) /* Reset all connected sockets when the device disappear */ vsock_for_each_connected_socket(virtio_vsock_reset_sock); + /* Stop all work handlers to make sure no one is accessing the device, + * so we can safely call vdev->config->reset(). + */ + mutex_lock(&vsock->rx_lock); + vsock->rx_run = false; + mutex_unlock(&vsock->rx_lock); + + mutex_lock(&vsock->tx_lock); + vsock->tx_run = false; + mutex_unlock(&vsock->tx_lock); + + mutex_lock(&vsock->event_lock); + vsock->event_run = false; + mutex_unlock(&vsock->event_lock); + + /* Flush all device writes and interrupts, device will not use any + * more buffers. + */ vdev->config->reset(vdev); mutex_lock(&vsock->rx_lock); @@ -667,12 +739,11 @@ static void virtio_vsock_remove(struct virtio_device *vdev) } spin_unlock_bh(&vsock->loopback_list_lock); - mutex_lock(&the_virtio_vsock_mutex); - the_virtio_vsock = NULL; - mutex_unlock(&the_virtio_vsock_mutex); - + /* Delete virtqueues and flush outstanding callbacks if any */ vdev->config->del_vqs(vdev); + mutex_unlock(&the_virtio_vsock_mutex); + kfree(vsock); } |