lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Mon,  1 Sep 2014 14:52:43 +0200
From:	Eric Auger <>
Subject: [RFC v2 4/9] VFIO: platform: handler tests whether the IRQ is forwarded

In case the IRQ is forwarded, the VFIO platform IRQ handler does not
need to disable the IRQ anymore. In that mode, when the handler completes
the IRQ is not deactivated but only its priority is lowered.

Some other actor (typically a guest) is supposed to deactivate the IRQ,
allowing at that time a new physical IRQ to hit.

In virtualization use case, the physical IRQ is automatically completed
by the interrupt controller when the guest completes the corresponding
virtual IRQ.

Signed-off-by: Eric Auger <>
 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 6768508..1f851b2 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -88,13 +88,18 @@ static irqreturn_t vfio_irq_handler(int irq, void *dev_id)
 	struct vfio_platform_irq *irq_ctx = dev_id;
 	unsigned long flags;
 	int ret = IRQ_NONE;
+	struct irq_data *d;
+	bool is_forwarded;
 	spin_lock_irqsave(&irq_ctx->lock, flags);
 	if (!irq_ctx->masked) {
 		ret = IRQ_HANDLED;
+		d = irq_get_irq_data(irq_ctx->hwirq);
+		is_forwarded = irqd_irq_forwarded(d);
-		if (irq_ctx->flags & VFIO_IRQ_INFO_AUTOMASKED) {
+		if (irq_ctx->flags & VFIO_IRQ_INFO_AUTOMASKED &&
+						!is_forwarded) {
 			irq_ctx->masked = true;

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists