Am 09.02.2018 um 14:32 schrieb Tom St Denis: > On 02/02/18 02:09 PM, Christian König wrote: >> [SNIP] >> +       if (p->mapping != adev->mman.bdev.dev_mapping) >> +           return -EPERM; > > This comparison fails for both IOMMU and non-IOMMU devices in my > carrizo+polaris10 box. > > The address being read from is what the VM decodes to (checked with > strace). Have you applied the whole series? That patches before this one are necessary to initialize p->mapping when there isn't any userspace mapping for the page. Christian. > > Tom