From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [RFC v2 4/9] VFIO: platform: handler tests whether the IRQ is forwarded Date: Mon, 1 Sep 2014 14:52:43 +0200 Message-ID: <1409575968-5329-5-git-send-email-eric.auger@linaro.org> References: <1409575968-5329-1-git-send-email-eric.auger@linaro.org> Cc: linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com To: eric.auger@st.com, eric.auger@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, alex.williamson@redhat.com, joel.schopp@amd.com, kim.phillips@freescale.com, paulus@samba.org, gleb@kernel.org, pbonzini@redhat.com Return-path: In-Reply-To: <1409575968-5329-1-git-send-email-eric.auger@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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) { disable_irq_nosync(irq_ctx->hwirq); irq_ctx->masked = true; } -- 1.9.1