diff options
| -rw-r--r-- | drivers/vfio/platform/vfio_platform_common.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 4df66f5fb313..d7fe2c71e8bc 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -55,6 +55,16 @@ 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; @@ -334,8 +344,63 @@ 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; } |