From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [PATCH v3 04/10] VFIO: platform: add vfio_platform_set_automasked Date: Mon, 17 Aug 2015 17:38:16 +0200 Message-ID: <55D1FFE8.9050104@linaro.org> References: <1439212864-12954-1-git-send-email-eric.auger@linaro.org> <1439212864-12954-5-git-send-email-eric.auger@linaro.org> <1439405794.4023.528.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: eric.auger@st.com, kvm@vger.kernel.org, patches@linaro.org, marc.zyngier@arm.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, pbonzini@redhat.com, feng.wu@intel.com, kvmarm@lists.cs.columbia.edu To: Alex Williamson Return-path: In-Reply-To: <1439405794.4023.528.camel@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu List-Id: kvm.vger.kernel.org On 08/12/2015 08:56 PM, Alex Williamson wrote: > On Mon, 2015-08-10 at 15:20 +0200, Eric Auger wrote: >> This function makes possible to change the automasked mode. >> >> Signed-off-by: Eric Auger >> >> --- >> >> v1 -> v2: >> - set forwarded flag >> --- >> drivers/vfio/platform/vfio_platform_irq.c | 19 +++++++++++++++++++ >> 1 file changed, 19 insertions(+) >> >> diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c >> index b31b1f0..a285384 100644 >> --- a/drivers/vfio/platform/vfio_platform_irq.c >> +++ b/drivers/vfio/platform/vfio_platform_irq.c >> @@ -186,6 +186,25 @@ static irqreturn_t vfio_handler(int irq, void *dev_id) >> return ret; >> } >> >> +static int vfio_platform_set_automasked(struct vfio_platform_irq *irq, >> + bool automasked) >> +{ >> + unsigned long flags; >> + >> + spin_lock_irqsave(&irq->lock, flags); >> + if (automasked) { >> + irq->forwarded = true; >> + irq->flags |= VFIO_IRQ_INFO_AUTOMASKED; >> + irq->handler = vfio_automasked_irq_handler; >> + } else { >> + irq->forwarded = false; >> + irq->flags &= ~VFIO_IRQ_INFO_AUTOMASKED; >> + irq->handler = vfio_irq_handler; >> + } >> + spin_unlock_irqrestore(&irq->lock, flags); >> + return 0; > > In vfio-speak, automasked means level and we're not magically changing > the IRQ from level to edge, we're simply able to handle level > differently based on a hardware optimization. Should the user visible > flags therefore change based on this? Aren't we really setting the > forwarded state rather than the automasked state? Well actually this was following the discussion we had a long time ago about that topic: http://lkml.iu.edu/hypermail/linux/kernel/1409.1/03659.html I did not really know how to conclude ... If it is preferred I can hide this to the userspace, no problem. Eric > >> +} >> + >> static void vfio_platform_irq_bypass_stop(struct irq_bypass_producer *prod) >> { >> } > > >