Hi Alex, On 3/9/24 00:05, Alex Williamson wrote:

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@oss.nxp.com Cc: stable@vger.kernel.org Fixes: cc0ee20bd969 ("vfio/fsl-mc: trigger an interrupt via eventfd") Signed-off-by: Alex Williamson alex.williamson@redhat.com

Reviewed-by: Eric Auger eric.auger@redhat.com

Eric

---

drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c index d62fbfff20b8..82b2afa9b7e3 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc_intr.c @@ -141,13 +141,14 @@ static int vfio_fsl_mc_set_irq_trigger(struct vfio_fsl_mc_device *vdev, irq = &vdev->mc_irqs[index]; if (flags & VFIO_IRQ_SET_DATA_NONE) {

• vfio_fsl_mc_irq_handler(hwirq, irq);
  

• if (irq->trigger)
  

• 	eventfd_signal(irq->trigger);
  

} else if (flags & VFIO_IRQ_SET_DATA_BOOL) { u8 trigger = *(u8 *)data;

• if (trigger)
  

• 	vfio_fsl_mc_irq_handler(hwirq, irq);
  

• if (trigger && irq->trigger)
  

• 	eventfd_signal(irq->trigger);
  

  }

return 0;