On 10.10.2017 12:53, Joerg Roedel wrote: > On Wed, Oct 04, 2017 at 04:02:31AM +0300, Dmitry Osipenko wrote: >> Due to a bug in IOVA allocator, page mapping could accidentally overwritten. >> We can catch this case by checking 'VALID' bit of GART's page entry prior to >> mapping of a page. Since that check introduces a noticeable performance >> impact, it should be enabled explicitly by a new >> CONFIG_TEGRA_IOMMU_GART_DEBUG >> option. > > Which bug in the IOVA allocator are you talking about? >
I'm not talking about any specific bug, but in general if allocator re-maps already mapped region or unmaps the wrong-and-used region. I had those bug-cases during of development of the 'scattered' graphics allocations for Tegra20. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
