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SubjectRe: [PATCH] vfio: Fix PCI 2.3 shared interrupt
Date
Applied.

On Wednesday, November 03, 2010 01:17:33 pm Alex Williamson wrote:
> Trying to be too clever with setting the irq_disabled flag. PCI 2.3
> disabled devices can still share IRQs, which can lead to clearing
> the irq_disabled flag, preventing the EOI from registering, and leaving
> the device without interrupts. Interrupt handler should only ever
> set irq_disabled and we can exit earlier to avoid the config space
> access if we know we're disabled.
>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>
> drivers/vfio/vfio_intrs.c | 9 ++++++++-
> 1 files changed, 8 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/vfio/vfio_intrs.c b/drivers/vfio/vfio_intrs.c
> index 604082c..73e3deb 100644
> --- a/drivers/vfio/vfio_intrs.c
> +++ b/drivers/vfio/vfio_intrs.c
> @@ -57,6 +57,12 @@ irqreturn_t vfio_interrupt(int irq, void *dev_id)
>
> spin_lock_irq(&vdev->irqlock);
>
> + /* INTX disabled interrupts can still be shared */
> + if (vdev->irq_disabled) {
> + spin_unlock_irq(&vdev->irqlock);
> + return ret;
> + }
> +
> if (vdev->pci_2_3) {
> pci_block_user_cfg_access(pdev);
>
> @@ -87,7 +93,8 @@ done:
> ret = IRQ_HANDLED;
> }
>
> - vdev->irq_disabled = (ret == IRQ_HANDLED);
> + if (ret == IRQ_HANDLED)
> + vdev->irq_disabled = true;
>
> spin_unlock_irq(&vdev->irqlock);


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