From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [PATCH v3 3/8] VFIO: platform: forwarded state tested when selecting IRQ handler Date: Mon, 01 Dec 2014 15:39:24 +0100 Message-ID: <547C7D9C.7030909@linaro.org> References: <1416767760-14487-1-git-send-email-eric.auger@linaro.org> <1416767760-14487-4-git-send-email-eric.auger@linaro.org> <20141130124730.GD82106@macair> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: eric.auger@st.com, 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, agraf@suse.de, linux-kernel@vger.kernel.org, patches@linaro.org, will.deacon@arm.com, a.motakis@virtualopensystems.com, a.rigo@virtualopensystems.com, john.liuli@huawei.com, ming.lei@canonical.com, feng.wu@intel.com To: Christoffer Dall Return-path: In-Reply-To: <20141130124730.GD82106@macair> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org 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: >> 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 >> >> --- >> >> 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 > >> --- >> 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 >>