Hi Christoffer,
On 11/30/2014 01:47 PM, Christoffer Dall wrote:

The subject reads strangely, perhaps just:

VFIO: platform: test forward state when selecting IRQ handler

OK

On Sun, Nov 23, 2014 at 07:35:55PM +0100, Eric Auger wrote:

quoted

In case the IRQ is forwarded, the VFIO platform IRQ handler does not
need to disable the IRQ anymore.

When setting the IRQ handler we now also test the forwarded state. In
case the IRQ is forwarded we select the edge handler (no automaske).

Signed-off-by: Eric Auger <redacted>

---

v2 -> v3:
- forwarded state was tested in the handler. Now the forwarded state
  is tested before setting the handler. This definitively limits
  the dynamics of forwarded state changes but I don't think there is
  a use case where we need to be able to change the state at any time.

user space can change this by calling the VFIO_IRQ_SET_ACTION_TRIGGER
whenever it wants, right?

yes the user can set/unset the VFIO signaling (and request_irq/free_irq)
using VFIO_IRQ_SET_ACTION_TRIGGER. In this new version I do not allow
changing the forwarded state when the handler is attached (request_irq).

Does it answer your interrogation?

Best Regards

Eric

quoted

---
 drivers/vfio/platform/vfio_platform_irq.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index 08d400e..61a2920 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c

@@ -230,8 +230,13 @@ static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev,
 {
 	struct vfio_platform_irq *irq = &vdev->irqs[index];
 	irq_handler_t handler;
+	struct irq_data *d;
+	bool is_forwarded;
 
-	if (vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE)
+	d = irq_get_irq_data(irq->hwirq);
+	is_forwarded = irqd_irq_forwarded(d);
+
+	if ((vdev->irqs[index].flags & VFIO_IRQ_INFO_MASKABLE) && !is_forwarded)
 		handler = vfio_maskable_irq_handler;
 	else
 		handler = vfio_irq_handler;

-- 
1.9.1