diff options
| -rw-r--r-- | drivers/s390/virtio/virtio_ccw.c | 9 | ||||
| -rw-r--r-- | drivers/virtio/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 2 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 12 | ||||
| -rw-r--r-- | include/linux/virtio_config.h | 2 |
5 files changed, 37 insertions, 1 deletions
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c index 97e51c34e6cf..161d3b141f0d 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -1136,8 +1136,13 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, vcdev->err = -EIO; } virtio_ccw_check_activity(vcdev, activity); - /* Interrupts are disabled here */ +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION + /* + * Paired with virtio_ccw_synchronize_cbs() and interrupts are + * disabled here. + */ read_lock(&vcdev->irq_lock); +#endif for_each_set_bit(i, indicators(vcdev), sizeof(*indicators(vcdev)) * BITS_PER_BYTE) { /* The bit clear must happen before the vring kick. */ @@ -1146,7 +1151,9 @@ static void virtio_ccw_int_handler(struct ccw_device *cdev, vq = virtio_ccw_vq_by_ind(vcdev, i); vring_interrupt(0, vq); } +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION read_unlock(&vcdev->irq_lock); +#endif if (test_bit(0, indicators2(vcdev))) { virtio_config_changed(&vcdev->vdev); clear_bit(0, indicators2(vcdev)); diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig index a6dc8b5846fe..e1556d2a355a 100644 --- a/drivers/virtio/Kconfig +++ b/drivers/virtio/Kconfig @@ -29,6 +29,19 @@ menuconfig VIRTIO_MENU if VIRTIO_MENU +config VIRTIO_HARDEN_NOTIFICATION + bool "Harden virtio notification" + help + Enable this to harden the device notifications and suppress + those that happen at a time where notifications are illegal. + + Experimental: Note that several drivers still have bugs that + may cause crashes or hangs when correct handling of + notifications is enforced; depending on the subset of + drivers and devices you use, this may or may not work. + + If unsure, say N. + config VIRTIO_PCI tristate "PCI driver for virtio devices" depends on PCI diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 6bace84ae37e..7deeed30d1f3 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -219,6 +219,7 @@ static int virtio_features_ok(struct virtio_device *dev) * */ void virtio_reset_device(struct virtio_device *dev) { +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION /* * The below virtio_synchronize_cbs() guarantees that any * interrupt for this line arriving after @@ -227,6 +228,7 @@ void virtio_reset_device(struct virtio_device *dev) */ virtio_break_device(dev); virtio_synchronize_cbs(dev); +#endif dev->config->reset(dev); } diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index ef30465dd39c..96731cdef422 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1708,7 +1708,11 @@ static struct virtqueue *vring_create_virtqueue_packed( vq->we_own_ring = true; vq->notify = notify; vq->weak_barriers = weak_barriers; +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION vq->broken = true; +#else + vq->broken = false; +#endif vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR); vq->event_triggered = false; vq->num_added = 0; @@ -2154,9 +2158,13 @@ irqreturn_t vring_interrupt(int irq, void *_vq) } if (unlikely(vq->broken)) { +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION dev_warn_once(&vq->vq.vdev->dev, "virtio vring IRQ raised before DRIVER_OK"); return IRQ_NONE; +#else + return IRQ_HANDLED; +#endif } /* Just a hint for performance: so it's ok that this can be racy! */ @@ -2199,7 +2207,11 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index, vq->we_own_ring = false; vq->notify = notify; vq->weak_barriers = weak_barriers; +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION vq->broken = true; +#else + vq->broken = false; +#endif vq->last_used_idx = 0; vq->event_triggered = false; vq->num_added = 0; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 49c7c32815f1..b47c2e7ed0ee 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -257,6 +257,7 @@ void virtio_device_ready(struct virtio_device *dev) WARN_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); +#ifdef CONFIG_VIRTIO_HARDEN_NOTIFICATION /* * The virtio_synchronize_cbs() makes sure vring_interrupt() * will see the driver specific setup if it sees vq->broken @@ -264,6 +265,7 @@ void virtio_device_ready(struct virtio_device *dev) */ virtio_synchronize_cbs(dev); __virtio_unbreak_device(dev); +#endif /* * The transport should ensure the visibility of vq->broken * before setting DRIVER_OK. See the comments for the transport |