On Tue, Nov 27, 2012 at 9:31 PM, Terje Bergstr?m <tbergstrom at nvidia.com> wrote: > On 27.11.2012 12:37, Thierry Reding wrote: >> But in that case it should be made mandatory at first until proper IOMMU >> support is enabled on Tegra30. Then it can be checked at driver probe >> time whether or not to enable the extra checks. That way we don't need a >> special Kconfig option and we still get all the security that we need, >> right? > > I guess it depends on the level of security. > > If we want to only protect kernel and user space memory, this would be > sufficient and no firewall is needed if IOMMU is turned on. > > If we want to protect 2D buffers from each other, this is not sufficient.
We generally aim for the first, to stop the gpu from reading/writing any memory it hasn't been granted access to, the second is nice to have though, but really requires a GPU with VM to implement properly. Dave.
