RE: [PATCH v2 7/7] vfio/fsl-mc: Block calling interrupt handler without trigger

[Tian, Kevin]

> From: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Sent: Saturday, March 9, 2024 7:05 AM
> 
> The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
> initially NULL and may become NULL if the user sets the trigger
> eventfd to -1.  The interrupt handler itself is guaranteed that
> trigger is always valid between request_irq() and free_irq(), but
> the loopback testing mechanisms to invoke the handler function
> need to test the trigger.  The triggering and setting ioctl paths
> both make use of igate and are therefore mutually exclusive.
> 
> The vfio-fsl-mc driver does not make use of irqfds, nor does it
> support any sort of masking operations, therefore unlike vfio-pci
> and vfio-platform, the flow can remain essentially unchanged.
> 
> Cc: Diana Craciun <diana.craciun@xxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd")
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>