Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751942AbaK0Reo (ORCPT ); Thu, 27 Nov 2014 12:34:44 -0500 Received: from mail-wg0-f46.google.com ([74.125.82.46]:38963 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751192AbaK0Rek (ORCPT ); Thu, 27 Nov 2014 12:34:40 -0500 From: Antonios Motakis To: kvmarm@lists.cs.columbia.edu, iommu@lists.linux-foundation.org, alex.williamson@redhat.com Cc: will.deacon@arm.com, tech@virtualopensystems.com, christoffer.dall@linaro.org, eric.auger@linaro.org, kim.phillips@freescale.com, marc.zyngier@arm.com, Antonios Motakis , kvm@vger.kernel.org (open list:VFIO DRIVER), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v10 09/20] vfio/platform: support MMAP of MMIO regions Date: Thu, 27 Nov 2014 18:32:49 +0100 Message-Id: <1417109580-10505-10-git-send-email-a.motakis@virtualopensystems.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1417109580-10505-1-git-send-email-a.motakis@virtualopensystems.com> References: <1417109580-10505-1-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. PIO regions are not being handled at this point. Signed-off-by: Antonios Motakis --- drivers/vfio/platform/vfio_platform_common.c | 65 ++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index fda4c30..6bf78ee 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -54,6 +54,16 @@ static int vfio_platform_regions_init(struct vfio_platform_device *vdev) if (!(res->flags & IORESOURCE_READONLY)) vdev->regions[i].flags |= 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; + break; case IORESOURCE_IO: vdev->regions[i].type = VFIO_PLATFORM_REGION_TYPE_PIO; @@ -333,8 +343,63 @@ static ssize_t vfio_platform_write(void *device_data, const char __user *buf, return -EINVAL; } +static int vfio_platform_mmap_mmio(struct vfio_platform_region region, + struct vm_area_struct *vma) +{ + u64 req_len, pgoff, req_start; + + 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 (region.size < PAGE_SIZE || req_start + req_len > region.size) + return -EINVAL; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff; + + return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + req_len, vma->vm_page_prot); +} + static int vfio_platform_mmap(void *device_data, struct vm_area_struct *vma) { + struct vfio_platform_device *vdev = device_data; + unsigned int index; + + 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)) + 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; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ) + && (vma->vm_flags & VM_READ)) + return -EINVAL; + + if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE) + && (vma->vm_flags & VM_WRITE)) + return -EINVAL; + + vma->vm_private_data = vdev; + + if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_MMIO) + return vfio_platform_mmap_mmio(vdev->regions[index], vma); + + else if (vdev->regions[index].type & VFIO_PLATFORM_REGION_TYPE_PIO) + return -EINVAL; /* not implemented */ + return -EINVAL; } -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/