linux-kernel - [PATCH v3 06/10] VFIO: platform: add irq bypass producer management

lists.openwall.net		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 linux-cve-announce 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, 10 Aug 2015 15:21:00 +0200
From:	Eric Auger <eric.auger@...aro.org>
To:	eric.auger@...com, eric.auger@...aro.org,
	linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu,
	kvm@...r.kernel.org, christoffer.dall@...aro.org,
	marc.zyngier@....com, alex.williamson@...hat.com, feng.wu@...el.com
Cc:	linux-kernel@...r.kernel.org, patches@...aro.org,
	pbonzini@...hat.com
Subject: [PATCH v3 06/10] VFIO: platform: add irq bypass producer management

This patch populates the IRQ bypass callacks:
- stop/start producer simply consist in disabling/enabling the host irq
- add/del consumer: basically set the automasked flag to false/true

Signed-off-by: Eric Auger <eric.auger@...aro.org>

---
v2 -> v3:
- vfio_platform_irq_bypass_add_consumer now returns an error in case
  the IRQ is recognized as active
- active boolean not set anymore
- do not VFIO mask the IRQ anymore on unforward

v1 -> v2:
- device handle caching in vfio_platform_device is introduced in a
  separate patch
- use container_of
---
 drivers/vfio/platform/vfio_platform_irq.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c
index efaee58..400a188 100644
--- a/drivers/vfio/platform/vfio_platform_irq.c
+++ b/drivers/vfio/platform/vfio_platform_irq.c
@@ -224,23 +224,44 @@ static int vfio_platform_is_active(struct vfio_platform_irq *irq)
 
 static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod)
 {
+	disable_irq(prod->irq);
 }
 
 static void vfio_platform_irq_bypass_start(struct irq_bypass_producer *prod)
 {
+	enable_irq(prod->irq);
 }
 
 static int vfio_platform_irq_bypass_add_consumer(
 			struct irq_bypass_producer *prod,
 			struct irq_bypass_consumer *cons)
 {
-	return 0;
+	struct vfio_platform_irq *irq =
+		container_of(prod, struct vfio_platform_irq, producer);
+
+	/*
+	 * if the IRQ is active at irqchip level or VFIO (auto)masked
+	 * this means the host IRQ is already under injection in the
+	 * guest and this not safe to change the forwarding state at
+	 * that stage.
+	 * It is not possible to differentiate user-space masking
+	 * from auto-masking, leading to possible false detection of
+	 * active state.
+	 */
+	if (vfio_platform_is_active(irq))
+		return -EAGAIN;
+
+	return vfio_platform_set_automasked(irq, false);
 }
 
 static void vfio_platform_irq_bypass_del_consumer(
 			struct irq_bypass_producer *prod,
 			struct irq_bypass_consumer *cons)
 {
+	struct vfio_platform_irq *irq =
+		container_of(prod, struct vfio_platform_irq, producer);
+
+	vfio_platform_set_automasked(irq, true);
 }
 
 static int vfio_set_trigger(struct vfio_platform_device *vdev, int index,
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/