diff options
| author | Jason Wang <jasowang@redhat.com> | 2022-06-22 09:29:40 +0800 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-06-24 02:49:48 -0400 |
| commit | c346dae4f3fbce51bbd4f2ec5e8c6f9b91e93163 (patch) | |
| tree | 4e3a09595a5ec554cf002679c587049c627fba49 /drivers/virtio | |
| parent | 03d9571706942fa653a4975709820596d13563c7 (diff) | |
virtio: disable notification hardening by default
We try to harden virtio device notifications in 8b4ec69d7e09 ("virtio:
harden vring IRQ"). It works with the assumption that the driver or
core can properly call virtio_device_ready() at the right
place. Unfortunately, this seems to be not true and uncover various
bugs of the existing drivers, mainly the issue of using
virtio_device_ready() incorrectly.
So let's add a Kconfig option and disable it by default. It gives
us time to fix the drivers and then we can consider re-enabling it.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220622012940.21441-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/virtio')
| -rw-r--r-- | drivers/virtio/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/virtio/virtio.c | 2 | ||||
| -rw-r--r-- | drivers/virtio/virtio_ring.c | 12 |
3 files changed, 27 insertions, 0 deletions
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; |