From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antonios Motakis Subject: [PATCHv7 17/26] vfio/platform: support MMAP of MMIO regions Date: Tue, 23 Sep 2014 16:46:16 +0200 Message-ID: <1411483586-29304-18-git-send-email-a.motakis@virtualopensystems.com> References: <1411483586-29304-1-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: <1411483586-29304-1-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: alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, kvmarm-FPEHb7Xf0XXUo1n7N8X6UoWGPAHP3yOg@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org 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 , Antonios Motakis , tech-lrHrjnjw1UfHK3s98zE1ajGjJy/sRE9J@public.gmane.org, christoffer.dall-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org List-Id: iommu@lists.linux-foundation.org Allow to memory map the MMIO regions of the device so userspace can directly access them. Signed-off-by: Antonios Motakis --- drivers/vfio/platform/vfio_platform_common.c | 40 +++++++++++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 589b226..5551d32 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -50,6 +50,11 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev) vdev->regions[i].size = resource_size(res); vdev->regions[i].flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; + /* Only regions addressed with PAGE granularity may be MMAPed + * securely. */ + if (!(vdev->regions[i].addr & ~PAGE_MASK) + && !(vdev->regions[i].size & ~PAGE_MASK)) + vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_MMAP; } vdev->num_regions = cnt; @@ -281,7 +286,40 @@ err: static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) { - return -EINVAL; + struct vfio_platform_device *vdev = device_data; + unsigned int index; + u64 req_len, pgoff, req_start; + struct vfio_platform_region regions; + + index = vma->vm_pgoff >> (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT); + + if (vma->vm_end < vma->vm_start) + return -EINVAL; + if ((vma->vm_flags & VM_SHARED) == 0) + return -EINVAL; + if (index >= vdev->num_regions) + return -EINVAL; + if (vma->vm_start & ~PAGE_MASK) + return -EINVAL; + if (vma->vm_end & ~PAGE_MASK) + return -EINVAL; + + regions = vdev->regions[index]; + + req_len = vma->vm_end - vma->vm_start; + pgoff = vma->vm_pgoff & + ((1U << (VFIO_PLATFORM_OFFSET_SHIFT - PAGE_SHIFT)) - 1); + req_start = pgoff << PAGE_SHIFT; + + if (regions.size < PAGE_SIZE || req_start + req_len > regions.size) + return -EINVAL; + + vma->vm_private_data = vdev; + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_pgoff = (regions.addr >> PAGE_SHIFT) + pgoff; + + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + req_len, vma->vm_page_prot); } static const struct vfio_device_ops vfio_platform_ops = { -- 1.8.3.2