diff options
Diffstat (limited to 'hw/virtio/vhost.c')
| -rw-r--r-- | hw/virtio/vhost.c | 122 |
1 files changed, 105 insertions, 17 deletions
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index fdcd1a8fdf..eb8c4c378c 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -1551,7 +1551,7 @@ void vhost_dev_cleanup(struct vhost_dev *hdev) int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) { BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); - int i, r, e; + int i, r; /* We will pass the notifiers to the kernel, make sure that QEMU * doesn't interfere. @@ -1559,32 +1559,29 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) r = virtio_device_grab_ioeventfd(vdev); if (r < 0) { error_report("binding does not support host notifiers"); - goto fail; + return r; } + /* + * Batch all the host notifiers in a single transaction to avoid + * quadratic time complexity in address_space_update_ioeventfds(). + */ + memory_region_transaction_begin(); + for (i = 0; i < hdev->nvqs; ++i) { r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, true); if (r < 0) { error_report("vhost VQ %d notifier binding failed: %d", i, -r); - goto fail_vq; + memory_region_transaction_commit(); + vhost_dev_disable_notifiers(hdev, vdev); + return r; } } + memory_region_transaction_commit(); + return 0; -fail_vq: - while (--i >= 0) { - e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, - false); - if (e < 0) { - error_report("vhost VQ %d notifier cleanup error: %d", i, -r); - } - assert (e >= 0); - virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); - } - virtio_device_release_ioeventfd(vdev); -fail: - return r; } /* Stop processing guest IO notifications in vhost. @@ -1597,6 +1594,12 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); int i, r; + /* + * Batch all the host notifiers in a single transaction to avoid + * quadratic time complexity in address_space_update_ioeventfds(). + */ + memory_region_transaction_begin(); + for (i = 0; i < hdev->nvqs; ++i) { r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i, false); @@ -1604,6 +1607,15 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) error_report("vhost VQ %d notifier cleanup failed: %d", i, -r); } assert (r >= 0); + } + + /* + * The transaction expects the ioeventfds to be open when it + * commits. Do it now, before the cleanup loop. + */ + memory_region_transaction_commit(); + + for (i = 0; i < hdev->nvqs; ++i) { virtio_bus_cleanup_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i); } virtio_device_release_ioeventfd(vdev); @@ -1640,7 +1652,68 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, file.index = hdev->vhost_ops->vhost_get_vq_index(hdev, n); r = hdev->vhost_ops->vhost_set_vring_call(hdev, &file); if (r < 0) { - VHOST_OPS_DEBUG(r, "vhost_set_vring_call failed"); + error_report("vhost_set_vring_call failed %d", -r); + } +} + +bool vhost_config_pending(struct vhost_dev *hdev) +{ + assert(hdev->vhost_ops); + if ((hdev->started == false) || + (hdev->vhost_ops->vhost_set_config_call == NULL)) { + return false; + } + + EventNotifier *notifier = + &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier; + return event_notifier_test_and_clear(notifier); +} + +void vhost_config_mask(struct vhost_dev *hdev, VirtIODevice *vdev, bool mask) +{ + int fd; + int r; + EventNotifier *notifier = + &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier; + EventNotifier *config_notifier = &vdev->config_notifier; + assert(hdev->vhost_ops); + + if ((hdev->started == false) || + (hdev->vhost_ops->vhost_set_config_call == NULL)) { + return; + } + if (mask) { + assert(vdev->use_guest_notifier_mask); + fd = event_notifier_get_fd(notifier); + } else { + fd = event_notifier_get_fd(config_notifier); + } + r = hdev->vhost_ops->vhost_set_config_call(hdev, fd); + if (r < 0) { + error_report("vhost_set_config_call failed %d", -r); + } +} + +static void vhost_stop_config_intr(struct vhost_dev *dev) +{ + int fd = -1; + assert(dev->vhost_ops); + if (dev->vhost_ops->vhost_set_config_call) { + dev->vhost_ops->vhost_set_config_call(dev, fd); + } +} + +static void vhost_start_config_intr(struct vhost_dev *dev) +{ + int r; + + assert(dev->vhost_ops); + int fd = event_notifier_get_fd(&dev->vdev->config_notifier); + if (dev->vhost_ops->vhost_set_config_call) { + r = dev->vhost_ops->vhost_set_config_call(dev, fd); + if (!r) { + event_notifier_set(&dev->vdev->config_notifier); + } } } @@ -1880,6 +1953,16 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) } } + r = event_notifier_init( + &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier, 0); + if (r < 0) { + return r; + } + event_notifier_test_and_clear( + &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier); + if (!vdev->use_guest_notifier_mask) { + vhost_config_mask(hdev, vdev, true); + } if (hdev->log_enabled) { uint64_t log_base; @@ -1918,6 +2001,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) vhost_device_iotlb_miss(hdev, vq->used_phys, true); } } + vhost_start_config_intr(hdev); return 0; fail_start: if (vrings) { @@ -1947,6 +2031,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) /* should only be called after backend is connected */ assert(hdev->vhost_ops); + event_notifier_test_and_clear( + &hdev->vqs[VHOST_QUEUE_NUM_CONFIG_INR].masked_config_notifier); + event_notifier_test_and_clear(&vdev->config_notifier); trace_vhost_dev_stop(hdev, vdev->name, vrings); @@ -1969,6 +2056,7 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev, bool vrings) } memory_listener_unregister(&hdev->iommu_listener); } + vhost_stop_config_intr(hdev); vhost_log_put(hdev, true); hdev->started = false; vdev->vhost_started = false; |