From 67247289688d49a610a956c23c4ff032f0281845 Mon Sep 17 00:00:00 2001 From: Diana Craciun Date: Mon, 5 Oct 2020 20:36:49 +0300 Subject: vfio/fsl-mc: Allow userspace to MMAP fsl-mc device MMIO regions Allow userspace to mmap device regions for direct access of fsl-mc devices. Signed-off-by: Bharat Bhushan Signed-off-by: Diana Craciun Reviewed-by: Eric Auger Signed-off-by: Alex Williamson --- drivers/vfio/fsl-mc/vfio_fsl_mc.c | 68 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 66 insertions(+), 2 deletions(-) (limited to 'drivers/vfio/fsl-mc') diff --git a/drivers/vfio/fsl-mc/vfio_fsl_mc.c b/drivers/vfio/fsl-mc/vfio_fsl_mc.c index 05dace5ddc2c..55190a2730fb 100644 --- a/drivers/vfio/fsl-mc/vfio_fsl_mc.c +++ b/drivers/vfio/fsl-mc/vfio_fsl_mc.c @@ -30,11 +30,20 @@ static int vfio_fsl_mc_regions_init(struct vfio_fsl_mc_device *vdev) for (i = 0; i < count; i++) { struct resource *res = &mc_dev->regions[i]; + int no_mmap = is_fsl_mc_bus_dprc(mc_dev); vdev->regions[i].addr = res->start; vdev->regions[i].size = resource_size(res); - vdev->regions[i].flags = 0; vdev->regions[i].type = mc_dev->regions[i].flags & IORESOURCE_BITS; + /* + * Only regions addressed with PAGE granularity may be + * MMAPed securely. + */ + if (!no_mmap && !(vdev->regions[i].addr & ~PAGE_MASK) && + !(vdev->regions[i].size & ~PAGE_MASK)) + vdev->regions[i].flags |= + VFIO_REGION_INFO_FLAG_MMAP; + } return 0; @@ -163,9 +172,64 @@ static ssize_t vfio_fsl_mc_write(void *device_data, const char __user *buf, return -EINVAL; } +static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region, + struct vm_area_struct *vma) +{ + u64 size = vma->vm_end - vma->vm_start; + u64 pgoff, base; + u8 region_cacheable; + + pgoff = vma->vm_pgoff & + ((1U << (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT)) - 1); + base = pgoff << PAGE_SHIFT; + + if (region.size < PAGE_SIZE || base + size > region.size) + return -EINVAL; + + region_cacheable = (region.type & FSL_MC_REGION_CACHEABLE) && + (region.type & FSL_MC_REGION_SHAREABLE); + if (!region_cacheable) + 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, + size, vma->vm_page_prot); +} + static int vfio_fsl_mc_mmap(void *device_data, struct vm_area_struct *vma) { - return -EINVAL; + struct vfio_fsl_mc_device *vdev = device_data; + struct fsl_mc_device *mc_dev = vdev->mc_dev; + int index; + + index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT); + + 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)) + return -EINVAL; + if (index >= mc_dev->obj_desc.region_count) + 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 = mc_dev; + + return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma); } static const struct vfio_device_ops vfio_fsl_mc_ops = { -- cgit v1.2.3