From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752237AbaFEVOS (ORCPT ); Thu, 5 Jun 2014 17:14:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19813 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321AbaFEVOQ (ORCPT ); Thu, 5 Jun 2014 17:14:16 -0400 Message-ID: <1402002841.9207.260.camel@ul30vt.home> Subject: Re: [RFC PATCH v6 10/20] vfio/platform: return info for device and its memory mapped IO regions From: Alex Williamson To: Antonios Motakis Cc: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, tech@virtualopensystems.com, a.rigo@virtualopensystems.com, kvm@vger.kernel.org, christoffer.dall@linaro.org, will.deacon@arm.com, kim.phillips@freescale.com, stuart.yoder@freescale.com, eric.auger@linaro.org, Catalin Marinas , Mark Rutland , Vladimir Murzin , open list Date: Thu, 05 Jun 2014 15:14:01 -0600 In-Reply-To: <1401987808-23596-11-git-send-email-a.motakis@virtualopensystems.com> References: <1401987808-23596-1-git-send-email-a.motakis@virtualopensystems.com> <1401987808-23596-11-git-send-email-a.motakis@virtualopensystems.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2014-06-05 at 19:03 +0200, Antonios Motakis wrote: > A VFIO userspace driver will start by opening the VFIO device > that corresponds to an IOMMU group, and will use the ioctl interface > to get the basic device info, such as number of memory regions and > interrupts, and their properties. > > This patch enables the IOCTLs: > - VFIO_DEVICE_GET_INFO > - VFIO_DEVICE_GET_REGION_INFO > > IRQ info is provided by one of the latter patches. > > Signed-off-by: Antonios Motakis > --- > drivers/vfio/platform/vfio_platform.c | 79 +++++++++++++++++++++++++-- > drivers/vfio/platform/vfio_platform_private.h | 17 ++++++ > 2 files changed, 90 insertions(+), 6 deletions(-) > > diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c > index 1df76d8..eeaebc4 100644 > --- a/drivers/vfio/platform/vfio_platform.c > +++ b/drivers/vfio/platform/vfio_platform.c > @@ -34,17 +34,66 @@ > #define DRIVER_AUTHOR "Antonios Motakis " > #define DRIVER_DESC "VFIO for platform devices - User Level meta-driver" > > +static int vfio_platform_regions_init(struct vfio_platform_device *vdev) > +{ > + int cnt = 0, i; > + > + while (platform_get_resource(vdev->pdev, IORESOURCE_MEM, cnt)) > + cnt++; > + > + vdev->region = kzalloc(sizeof(struct vfio_platform_region) * cnt, > + GFP_KERNEL); > + if (!vdev->region) > + return -ENOMEM; > + > + for (i = 0; i < cnt; i++) { > + struct resource *res = > + platform_get_resource(vdev->pdev, IORESOURCE_MEM, i); > + > + if (!res) > + goto err; > + > + vdev->region[i].addr = res->start; > + vdev->region[i].size = resource_size(res); > + vdev->region[i].flags = 0; > + } > + > + vdev->num_regions = cnt; > + > + return 0; > +err: > + kfree(vdev->region); > + return -EINVAL; > +} > + > +static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) > +{ > + vdev->num_regions = 0; > + kfree(vdev->region); > +} > + > static void vfio_platform_release(void *device_data) > { > + struct vfio_platform_device *vdev = device_data; > + > + vfio_platform_regions_cleanup(vdev); > + > module_put(THIS_MODULE); > } > > static int vfio_platform_open(void *device_data) > { > + struct vfio_platform_device *vdev = device_data; > + int ret; > + > if (!try_module_get(THIS_MODULE)) > return -ENODEV; > > - return 0; > + ret = vfio_platform_regions_init(vdev); > + if (ret) > + module_put(THIS_MODULE); > + > + return ret; The user can call VFIO_GROUP_GET_DEVICE_FD for a single device more than once, vfio_pci maintains a reference count to make sure we only allocate and initialize on the first open and cleanup on the last close. > } > > static long vfio_platform_ioctl(void *device_data, > @@ -65,18 +114,36 @@ static long vfio_platform_ioctl(void *device_data, > return -EINVAL; > > info.flags = VFIO_DEVICE_FLAGS_PLATFORM; > - info.num_regions = 0; > + info.num_regions = vdev->num_regions; > info.num_irqs = 0; > > return copy_to_user((void __user *)arg, &info, minsz); > > - } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) > - return -EINVAL; > + } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) { > + struct vfio_region_info info; > + > + minsz = offsetofend(struct vfio_region_info, offset); > + > + if (copy_from_user(&info, (void __user *)arg, minsz)) > + return -EFAULT; > + > + if (info.argsz < minsz) > + return -EINVAL; > + > + if (info.index >= vdev->num_regions) > + return -EINVAL; > + > + /* map offset to the physical address */ > + info.offset = VFIO_PLATFORM_INDEX_TO_OFFSET(info.index); > + info.size = vdev->region[info.index].size; > + info.flags = vdev->region[info.index].flags; > + > + return copy_to_user((void __user *)arg, &info, minsz); > > - else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) > + } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) { > return -EINVAL; > > - else if (cmd == VFIO_DEVICE_SET_IRQS) > + } else if (cmd == VFIO_DEVICE_SET_IRQS) > return -EINVAL; > > else if (cmd == VFIO_DEVICE_RESET) > diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h > index 4ae88f8..3448f918 100644 > --- a/drivers/vfio/platform/vfio_platform_private.h > +++ b/drivers/vfio/platform/vfio_platform_private.h > @@ -15,8 +15,25 @@ > #ifndef VFIO_PLATFORM_PRIVATE_H > #define VFIO_PLATFORM_PRIVATE_H > > +#define VFIO_PLATFORM_OFFSET_SHIFT 40 > +#define VFIO_PLATFORM_OFFSET_MASK (((u64)(1) << VFIO_PLATFORM_OFFSET_SHIFT) - 1) > + > +#define VFIO_PLATFORM_OFFSET_TO_INDEX(off) \ > + (off >> VFIO_PLATFORM_OFFSET_SHIFT) > + > +#define VFIO_PLATFORM_INDEX_TO_OFFSET(index) \ > + ((u64)(index) << VFIO_PLATFORM_OFFSET_SHIFT) > + > +struct vfio_platform_region { > + u64 addr; > + resource_size_t size; > + u32 flags; > +}; > + > struct vfio_platform_device { > struct platform_device *pdev; > + struct vfio_platform_region *region; "regions" (plural) has slightly better consistency. Thanks, Alex > + u32 num_regions; > }; > > #endif /* VFIO_PLATFORM_PRIVATE_H */