virtio: disable notification hardening by default

We try to harden virtio device notifications in 8b4ec69d7e ("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>
This commit is contained in:
Jason Wang
2022-06-22 09:29:40 +08:00
committed by Michael S. Tsirkin
parent 03d9571706
commit c346dae4f3
5 changed files with 37 additions and 1 deletions

View File

@@ -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