From c346dae4f3fbce51bbd4f2ec5e8c6f9b91e93163 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Wed, 22 Jun 2022 09:29:40 +0800 Subject: 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 Message-Id: <20220622012940.21441-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Cornelia Huck --- drivers/s390/virtio/virtio_ccw.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/s390') 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)); -- cgit v1.2.3