On 9/3/19 1:36 PM, Thomas Hellström (VMware) wrote: > So the question here should really be, can we determine already at mmap > time whether backing memory will be unencrypted and adjust the *real* > vma->vm_page_prot under the mmap_sem? > > Possibly, but that requires populating the buffer with memory at mmap > time rather than at first fault time.
I'm not connecting the dots. vma->vm_page_prot is used to create a VMA's PTEs regardless of if they are created at mmap() or fault time. If we establish a good vma->vm_page_prot, can't we just use it forever for demand faults? Or, are you concerned that if an attempt is made to demand-fault page that's incompatible with vma->vm_page_prot that we have to SEGV? > And it still requires knowledge whether the device DMA is always > unencrypted (or if SEV is active). I may be getting mixed up on MKTME (the Intel memory encryption) and SEV. Is SEV supported on all memory types? Page cache, hugetlbfs, anonymous? Or just anonymous? _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
