Hi Sricharan, On 02/12/16 14:55, Sricharan R wrote: > This series is a resend of the V5 that Mitch sent sometime back [2] > All the patches are the same and i have just rebased. Not sure why this > finally did not make it last time. The last patch in the previous > series does not apply now [3], so just redid that. Also Copied the tags > that he had from last time as well.
Heh, I was assuming this would be down to me to pick up. Vinod did have some complaints last time about the commit message on the PL330 patch - I did get as far as rewriting that and reworking onto my SMMU changes[1], I just hadn't got round to sending it, so it fell onto the "after the next merge window" pile. I'd give some review comments, but they'd essentially be a diff against that branch :) Robin. [1]:http://www.linux-arm.org/git?p=linux-rm.git;a=shortlog;h=refs/heads/mh/dma-priv > The following patch to the ARM SMMU driver: > > commit d346180e70b91b3d5a1ae7e5603e65593d4622bc > Author: Robin Murphy <robin.mur...@arm.com> > Date: Tue Jan 26 18:06:34 2016 +0000 > > iommu/arm-smmu: Treat all device transactions as unprivileged > > started forcing all SMMU transactions to come through as "unprivileged". > The rationale given was that: > > (1) There is no way in the IOMMU API to even request privileged > mappings. > > (2) It's difficult to implement a DMA mapper that correctly models the > ARM VMSAv8 behavior of unprivileged-writeable => > privileged-execute-never. > > This series rectifies (1) by introducing an IOMMU API for privileged > mappings and implements it in io-pgtable-arm. > > This series rectifies (2) by introducing a new dma attribute > (DMA_ATTR_PRIVILEGED) for users of the DMA API that need privileged > mappings which are inaccessible to lesser-privileged execution levels, and > implements it in the arm64 IOMMU DMA mapper. The one known user (pl330.c) > is converted over to the new attribute. > > Jordan and Jeremy can provide more info on the use case if needed, but the > high level is that it's a security feature to prevent attacks such as [1]. > > [1] https://github.com/robclark/kilroy > [2] https://lkml.org/lkml/2016/7/27/590 > [3] https://patchwork.kernel.org/patch/9250493/ > > Changelog: > > v5..v6 > - Rebased all the patches and redid 6/6 as it does not apply in > this code base. > > v4..v5 > > - Simplified patch 4/6 (suggested by Robin Murphy). > > v3..v4 > > - Rebased and reworked on linux next due to the dma attrs rework going > on over there. Patches changed: 3/6, 4/6, and 5/6. > > v2..v3 > > - Incorporated feedback from Robin: > * Various comments and re-wordings. > * Use existing bit definitions for IOMMU_PRIV implementation > in io-pgtable-arm. > * Renamed and redocumented dma_direction_to_prot. > * Don't worry about executability in new DMA attr. > > v1..v2 > > - Added a new DMA attribute to make executable privileged mappings > work, and use that in the pl330 driver (suggested by Will). > > Jeremy Gebben (1): > iommu/io-pgtable-arm: add support for the IOMMU_PRIV flag > > Mitchel Humpherys (4): > iommu: add IOMMU_PRIV attribute > common: DMA-mapping: add DMA_ATTR_PRIVILEGED attribute > arm64/dma-mapping: Implement DMA_ATTR_PRIVILEGED > dmaengine: pl330: Make sure microcode is privileged > > Sricharan R (1): > iommu/arm-smmu: Set privileged attribute to 'default' instead of > 'unprivileged' > > Documentation/DMA-attributes.txt | 10 ++++++++++ > arch/arm64/mm/dma-mapping.c | 6 +++--- > drivers/dma/pl330.c | 6 ++++-- > drivers/iommu/arm-smmu.c | 2 +- > drivers/iommu/dma-iommu.c | 10 ++++++++-- > drivers/iommu/io-pgtable-arm.c | 5 ++++- > include/linux/dma-iommu.h | 3 ++- > include/linux/dma-mapping.h | 7 +++++++ > include/linux/iommu.h | 1 + > 9 files changed, 40 insertions(+), 10 deletions(-) > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
