On Mon, Oct 14, 2013 at 06:09:48PM +0100, Will Deacon wrote: > On Mon, Oct 14, 2013 at 04:17:51PM +0100, Antonios Motakis wrote: > > On Mon, Oct 14, 2013 at 2:48 PM, Will Deacon <will.deacon@xxxxxxx> wrote: > > > On Fri, Oct 11, 2013 at 02:24:47PM +0100, Antonios Motakis wrote: > > VFIO will exercise this code path every time when mapping DMA memory. > > This is normal and VFIO *expects* the function to fail - it is only if > > the function succeeds that VFIO needs to back down from the DMA > > mapping and fail. > > > > This means that there would be a warning every time a VFIO user maps > > some memory for DMA use, even though nothing went wrong. > > Ok, in which case it might be worth reworking arm_smmu_iova_to_phys to treat > {pgd,pud,pmd,pte}_none different from {pgd,pud,pmd,pte}_bad. Just an FYI, but I realised the page table locking is broken in my driver (hold a spinlock over a non-atomic allocation; looks like the exynos guys do this too), so I've just reworked a bunch of iova_to_phys and incorporated this change as part of that. Cheers, Will _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm