From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCHv7 20/26] vfio/platform: trigger an interrupt via eventfd Date: Wed, 24 Sep 2014 11:00:09 -0600 Message-ID: <1411578009.24563.107.camel@ul30vt.home> References: <1411483586-29304-1-git-send-email-a.motakis@virtualopensystems.com> <1411483586-29304-21-git-send-email-a.motakis@virtualopensystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1411483586-29304-21-git-send-email-a.motakis-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Antonios Motakis Cc: kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, eric.auger-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, open list , iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, tech-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org, kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Tue, 2014-09-23 at 16:46 +0200, Antonios Motakis wrote: > This patch allows to set an eventfd for a patform device's interrupt, > and also to trigger the interrupt eventfd from userspace for testing. > > Signed-off-by: Antonios Motakis > --- > drivers/vfio/platform/vfio_platform_irq.c | 89 ++++++++++++++++++++++++++- > drivers/vfio/platform/vfio_platform_private.h | 2 + > 2 files changed, 89 insertions(+), 2 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform_irq.c b/drivers/vfio/platform/vfio_platform_irq.c > index 007b386..25a7825 100644 > --- a/drivers/vfio/platform/vfio_platform_irq.c > +++ b/drivers/vfio/platform/vfio_platform_irq.c > @@ -45,11 +45,91 @@ static int vfio_platform_set_irq_unmask(struct vfio_platform_device *vdev, > return -EINVAL; > } > > +static irqreturn_t vfio_irq_handler(int irq, void *dev_id) > +{ > + struct vfio_platform_irq *irq_ctx = dev_id; > + > + eventfd_signal(irq_ctx->trigger, 1); > + > + return IRQ_HANDLED; > +} > + > +static int vfio_set_trigger(struct vfio_platform_device *vdev, > + int index, int fd) > +{ > + struct vfio_platform_irq *irq = &vdev->irqs[index]; > + struct eventfd_ctx *trigger; > + int ret; > + > + if (irq->trigger) { > + free_irq(irq->hwirq, irq); > + kfree(irq->name); > + eventfd_ctx_put(irq->trigger); > + irq->trigger = NULL; > + } > + > + if (fd < 0) /* Disable only */ > + return 0; > + > + irq->name = kasprintf(GFP_KERNEL, "vfio-irq[%d](%s)", > + irq->hwirq, vdev->name); > + if (!irq->name) > + return -ENOMEM; > + > + trigger = eventfd_ctx_fdget(fd); > + if (IS_ERR(trigger)) { > + kfree(irq->name); > + return PTR_ERR(trigger); > + } > + > + irq->trigger = trigger; > + > + ret = request_irq(irq->hwirq, vfio_irq_handler, 0, irq->name, irq); > + if (ret) { > + kfree(irq->name); > + eventfd_ctx_put(trigger); > + irq->trigger = NULL; > + return ret; > + } > + > + return 0; > +} > + > static int vfio_platform_set_irq_trigger(struct vfio_platform_device *vdev, > unsigned index, unsigned start, > unsigned count, uint32_t flags, void *data) > { > - return -EINVAL; > + struct vfio_platform_irq *irq = &vdev->irqs[index]; > + uint8_t irq_bitmap; Minor nit here and also present in the next patch, I believe when we have DATA_BOOL, it's defined to be a u8 array, where each byte is a bool, not each bit. So it's not actually a bitmap. The PCI code handles any non-zero byte as true, not just bit0. Thanks, Alex > + int32_t fd; > + > + switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) { > + case VFIO_IRQ_SET_DATA_NONE: > + if (count == 0) > + return vfio_set_trigger(vdev, index, -1); > + > + vfio_irq_handler(irq->hwirq, irq); > + return 0; > + > + case VFIO_IRQ_SET_DATA_BOOL: > + if (copy_from_user(&irq_bitmap, data, sizeof(uint8_t))) > + return -EFAULT; > + > + if (irq_bitmap == 0x1) { > + vfio_irq_handler(irq->hwirq, irq); > + return 0; > + } > + > + return -EINVAL; > + > + case VFIO_IRQ_SET_DATA_EVENTFD: > + if (copy_from_user(&fd, data, sizeof(int32_t))) > + return -EFAULT; > + > + return vfio_set_trigger(vdev, index, fd); > + } > + > + return -EFAULT; > } > > int vfio_platform_set_irqs_ioctl(struct vfio_platform_device *vdev, > @@ -95,7 +175,7 @@ int vfio_platform_irq_init(struct vfio_platform_device *vdev) > if (hwirq < 0) > goto err; > > - vdev->irqs[i].flags = 0; > + vdev->irqs[i].flags = VFIO_IRQ_INFO_EVENTFD; > vdev->irqs[i].count = 1; > vdev->irqs[i].hwirq = hwirq; > } > @@ -110,6 +190,11 @@ err: > > void vfio_platform_irq_cleanup(struct vfio_platform_device *vdev) > { > + int i; > + > + for (i = 0; i < vdev->num_irqs; i++) > + vfio_set_trigger(vdev, i, -1); > + > vdev->num_irqs = 0; > kfree(vdev->irqs); > } > diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h > index 4201b94..765b371 100644 > --- a/drivers/vfio/platform/vfio_platform_private.h > +++ b/drivers/vfio/platform/vfio_platform_private.h > @@ -28,6 +28,8 @@ struct vfio_platform_irq { > u32 flags; > u32 count; > int hwirq; > + char *name; > + struct eventfd_ctx *trigger; > }; > > struct vfio_platform_region {