From mboxrd@z Thu Jan 1 00:00:00 1970 From: eric.auger@linaro.org (Eric Auger) Date: Mon, 10 Aug 2015 15:21:00 +0200 Subject: [PATCH v3 06/10] VFIO: platform: add irq bypass producer management In-Reply-To: <1439212864-12954-1-git-send-email-eric.auger@linaro.org> References: <1439212864-12954-1-git-send-email-eric.auger@linaro.org> Message-ID: <1439212864-12954-7-git-send-email-eric.auger@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 --- 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