From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751663Ab3LKVAY (ORCPT ); Wed, 11 Dec 2013 16:00:24 -0500 Received: from mail-wg0-f52.google.com ([74.125.82.52]:63579 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598Ab3LKVAQ (ORCPT ); Wed, 11 Dec 2013 16:00:16 -0500 From: Antonios Motakis To: alex.williamson@redhat.com, kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org Cc: tech@virtualopensystems.com, a.rigo@virtualopensystems.com, B08248@freescale.com, kim.phillips@linaro.org, Antonios Motakis , kvm@vger.kernel.org (open list:VFIO DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH 6/9] VFIO_PLATFORM: Support MMAP of MMIO regions Date: Wed, 11 Dec 2013 21:58:30 +0100 Message-Id: <1386795513-32426-7-git-send-email-a.motakis@virtualopensystems.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1386795513-32426-1-git-send-email-a.motakis@virtualopensystems.com> References: <1386795513-32426-1-git-send-email-a.motakis@virtualopensystems.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Allow to memory map the MMIO regions of the device so userspace can directly access them. Signed-off-by: Antonios Motakis Tested-by: Alvise Rigo --- drivers/vfio/platform/vfio_platform.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform.c b/drivers/vfio/platform/vfio_platform.c index d0b2941..9786660 100644 --- a/drivers/vfio/platform/vfio_platform.c +++ b/drivers/vfio/platform/vfio_platform.c @@ -58,6 +58,11 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev) region.flags = VFIO_REGION_INFO_FLAG_READ | VFIO_REGION_INFO_FLAG_WRITE; + /* Only regions addressed with PAGE granularity can be MMAPed + * securely. */ + if (!(region.addr & ~PAGE_MASK) && !(region.size & ~PAGE_MASK)) + region.flags |= VFIO_REGION_INFO_FLAG_MMAP; + vdev->region[i] = region; } @@ -283,6 +288,34 @@ err: static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) { + struct vfio_platform_device *vdev = device_data; + u64 req_len = vma->vm_end - vma->vm_start; + u64 addr = vma->vm_pgoff << PAGE_SHIFT; + int i; + + if (vma->vm_end < vma->vm_start) + return -EINVAL; + if (vma->vm_start & ~PAGE_MASK) + return -EINVAL; + if (vma->vm_end & ~PAGE_MASK) + return -EINVAL; + if ((vma->vm_flags & VM_SHARED) == 0) + return -EINVAL; + + for (i = 0; i < vdev->num_regions; i++) { + struct vfio_platform_region region = vdev->region[i]; + + if ((addr < region.addr) + || (addr + req_len - 1) >= (region.addr + region.size)) + continue; + + vma->vm_private_data = vdev; + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + req_len, vma->vm_page_prot); + } + return -EINVAL; } -- 1.8.3.2