From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752282AbcLBQRP (ORCPT ); Fri, 2 Dec 2016 11:17:15 -0500 Received: from foss.arm.com ([217.140.101.70]:43914 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783AbcLBQQn (ORCPT ); Fri, 2 Dec 2016 11:16:43 -0500 Subject: Re: [RESEND PATCH V6 0/6] Add support for privileged mappings To: Sricharan R , jcrouse@codeaurora.org, pdaly@codeaurora.org, jgebben@codeaurora.org, joro@8bytes.org, linux-kernel@vger.kernel.org, pratikp@codeaurora.org, iommu@lists.linux-foundation.org, tzeng@codeaurora.org, linux-arm-kernel@lists.infradead.org, will.deacon@arm.com, mitchelh@codeaurora.org, vinod.koul@intel.com References: <1480690509-13490-1-git-send-email-sricharan@codeaurora.org> From: Robin Murphy Message-ID: Date: Fri, 2 Dec 2016 16:16:39 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <1480690509-13490-1-git-send-email-sricharan@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > 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(-) > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [RESEND PATCH V6 0/6] Add support for privileged mappings Date: Fri, 2 Dec 2016 16:16:39 +0000 Message-ID: References: <1480690509-13490-1-git-send-email-sricharan@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1480690509-13490-1-git-send-email-sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Sricharan R , jcrouse-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, pdaly-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, jgebben-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, pratikp-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, tzeng-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, mitchelh-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, vinod.koul-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org 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 > 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(-) > From mboxrd@z Thu Jan 1 00:00:00 1970 From: robin.murphy@arm.com (Robin Murphy) Date: Fri, 2 Dec 2016 16:16:39 +0000 Subject: [RESEND PATCH V6 0/6] Add support for privileged mappings In-Reply-To: <1480690509-13490-1-git-send-email-sricharan@codeaurora.org> References: <1480690509-13490-1-git-send-email-sricharan@codeaurora.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > 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(-) >