Messages in this thread | | | From | Cornelia Huck <> | Subject | Re: [PATCH V6 8/9] virtio: harden vring IRQ | Date | Mon, 30 May 2022 17:18:08 +0200 |
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On Fri, May 27 2022, Jason Wang <jasowang@redhat.com> wrote:
> 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> > --- > drivers/s390/virtio/virtio_ccw.c | 4 ++++ > drivers/virtio/virtio.c | 15 ++++++++++++--- > drivers/virtio/virtio_mmio.c | 5 +++++ > drivers/virtio/virtio_pci_modern_dev.c | 5 +++++ > drivers/virtio/virtio_ring.c | 11 +++++++---- > include/linux/virtio_config.h | 20 ++++++++++++++++++++ > 6 files changed, 53 insertions(+), 7 deletions(-)
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
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