diff options
| author | Jason Wang <jasowang@redhat.com> | 2022-05-27 08:01:19 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2022-05-31 18:45:10 +0200 |
| commit | 8b4ec69d7e098a7ddf832e1e7840de53ed474c77 (patch) | |
| tree | bdb4776afb38a0ab34b028987924967a941fe2f7 /drivers/virtio/virtio.c | |
| parent | virtio: allow to unbreak virtqueue (diff) | |
| download | linux-8b4ec69d7e098a7ddf832e1e7840de53ed474c77.tar.xz linux-8b4ec69d7e098a7ddf832e1e7840de53ed474c77.zip | |
virtio: harden vring IRQ
This is a rework on the previous IRQ hardening that is done for
virtio-pci where several drawbacks were found and were reverted:
1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ
that is used by some device such as virtio-blk
2) done only for PCI transport
The vq->broken is re-used in this patch for implementing the IRQ
hardening. The vq->broken is set to true during both initialization
and reset. And the vq->broken is set to false in
virtio_device_ready(). Then vring_interrupt() can check and return
when vq->broken is true. And in this case, switch to return IRQ_NONE
to let the interrupt core aware of such invalid interrupt to prevent
IRQ storm.
The reason of using a per queue variable instead of a per device one
is that we may need it for per queue reset hardening in the future.
Note that the hardening is only done for vring interrupt since the
config interrupt hardening is already done in commit 22b7050a024d7
("virtio: defer config changed notifications"). But the method that is
used by config interrupt can't be reused by the vring interrupt
handler because it uses spinlock to do the synchronization which is
expensive.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Vineeth Vijayan <vneethv@linux.ibm.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220527060120.20964-9-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Diffstat (limited to 'drivers/virtio/virtio.c')
| -rw-r--r-- | drivers/virtio/virtio.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index aa1eb5132767..95fac4c97c8b 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -220,6 +220,15 @@ static int virtio_features_ok(struct virtio_device *dev) * */ void virtio_reset_device(struct virtio_device *dev) { + /* + * The below virtio_synchronize_cbs() guarantees that any + * interrupt for this line arriving after + * virtio_synchronize_vqs() has completed is guaranteed to see + * vq->broken as true. + */ + virtio_break_device(dev); + virtio_synchronize_cbs(dev); + dev->config->reset(dev); } EXPORT_SYMBOL_GPL(virtio_reset_device); @@ -428,6 +437,9 @@ int register_virtio_device(struct virtio_device *dev) dev->config_enabled = false; dev->config_change_pending = false; + INIT_LIST_HEAD(&dev->vqs); + spin_lock_init(&dev->vqs_list_lock); + /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ virtio_reset_device(dev); @@ -435,9 +447,6 @@ int register_virtio_device(struct virtio_device *dev) /* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); - INIT_LIST_HEAD(&dev->vqs); - spin_lock_init(&dev->vqs_list_lock); - /* * device_add() causes the bus infrastructure to look for a matching * driver. |