From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 44A9F366563; Mon, 27 Apr 2026 05:55:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777269323; cv=none; b=F2koh/933J7NtHcA/OindgQTLovY59e9xvh7MtI8Nsa0ZF5PSnIy2A5d/B9tUBdYeXlvOKADmQufJE5j6NBoNvSAdrluqmdgmBUp540z+QbaBRq2N9XhKn/SS+fKQXzgwFz0xKtUkOL/+d5Jamuas7/4Bw4Z+maB6v5IKU4zw9w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777269323; c=relaxed/simple; bh=6ZjxOpU68srlH3qry9A0v7Th0kxY8yaBOyYCtR4Ku2o=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lGijvsYnwcmQgtUlva8aD2glr9rogu3otulNnc27h4TrnAMQ1LAZnlx31PMDtOJcRnGORIQla48By81aEf/+fsKrW5kqGv60yv4cMzYmiSHl9iYZcsygA+qmA4wc130+LaGdO0Di48ysmZUBAq2cCVh+nUTUzHHxpdqxO59PlRA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a91uPiwT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a91uPiwT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4065C19425; Mon, 27 Apr 2026 05:55:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777269322; bh=6ZjxOpU68srlH3qry9A0v7Th0kxY8yaBOyYCtR4Ku2o=; h=From:To:Cc:Subject:Date:From; b=a91uPiwTgoduDRliXTq1Qc6Ts1j0KVr/JxNT2CI+aO0PRIy2V58/OJxFY+wDgIEMV lqAjjWUryGT1QJSV3wHctJ3n/AU3sPy6+05aiK84fsYVaYiTdtviEaPN+sHAB9/xuV 5ufA5wWH8oJKmCZoNL8S1HqziXDAfVJ6zcdfS5Cmtq9s31N2gZgfPU3q81YC5SXwIQ /Ql7hxJW3MACjewVAeVAF63P68UxbRd3nepK5kXFN27ibyWeEyGJ5TuM7iO1LU+dJ6 CBS7/NR5lOmURfhMMNn/c6baMZBhmjliiBk9ngZItdLgfAFuMqCZi77vIudxBUjvv5 3fesTp+wm3iUw== From: "Aneesh Kumar K.V (Arm)" To: iommu@lists.linux.dev, linux-kernel@vger.kernel.org Cc: "Aneesh Kumar K.V (Arm)" , Robin Murphy , Marek Szyprowski , Will Deacon , Marc Zyngier , Steven Price , Suzuki K Poulose , Catalin Marinas , Jiri Pirko , Jason Gunthorpe , Mostafa Saleh , Petr Tesarik , Alexey Kardashevskiy , Dan Williams , Xu Yilun Subject: [PATCH v3 0/9] dma-mapping: Use DMA_ATTR_CC_SHARED through direct, pool and swiotlb paths Date: Mon, 27 Apr 2026 11:25:00 +0530 Message-ID: <20260427055509.898190-1-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This series propagates DMA_ATTR_CC_SHARED through the dma-direct, dma-pool, and swiotlb paths so that encrypted and decrypted DMA buffers are handled consistently. Today, the direct DMA path mostly relies on force_dma_unencrypted() for shared/decrypted buffer handling. This series consolidates the force_dma_unencrypted() checks in the top-level functions and ensures that the remaining DMA interfaces use DMA attributes to make the correct decisions. The series: - moves swiotlb-backed allocations out of __dma_direct_alloc_pages(), - propagates DMA_ATTR_CC_SHARED through the dma-direct alloc/free paths - teaches the atomic DMA pools to track encrypted versus decrypted state - tracks swiotlb pool encryption state and enforces strict pool selection - centralizes encrypted/decrypted pgprot handling in dma_pgprot() using DMA attributes - passes DMA attributes down to dma_capable() so capability checks can validate whether the selected DMA address encoding matches DMA_ATTR_CC_SHARED - makes dma_direct_map_phys() choose the DMA address encoding from DMA_ATTR_CC_SHARED and fall back to swiotlb when a shared DMA request cannot use the direct mapping, which lets arm64 and x86 CCA guests stop relying on SWIOTLB_FORCE for DMA mappings - use the selected swiotlb pool state to derive the returned DMA address. Changes from v2: https://lore.kernel.org/all/20260420061415.3650870-1-aneesh.kumar@kernel.org * pass attrs to dma_capable() and update direct, swiotlb, Xen swiotlb, and x86 GART paths so the capability checks see the DMA address attr value DMA_ATTR_CC_SHARED. * rework dma_direct_map_phys() so DMA_ATTR_CC_SHARED selects phys_to_dma_unencrypted() while the default path uses phys_to_dma_encrypted(), with swiotlb fallback when the requested shared/private state cannot be satisfied by a direct DMA address. * stop relying on SWIOTLB_FORCE for arm64 and x86 CC guest DMA mappings; swiotlb is still enabled there, but shared mappings is now selected through the generic dma_direct_map_phys()/dma_capable() decision instead of a global force-bounce flag. Changes from v1: https://lore.kernel.org/all/20260417085900.3062416-1-aneesh.kumar@kernel.org * rebased to latest kernel (change from DMA_ATTR_CC_DECRYPTED -> DMA_ATTR_CC_SHARED) * update the alloc path so DMA_ATTR_CC_SHARED is not a caller-visible attribute. Cc: Robin Murphy Cc: Marek Szyprowski Cc: Will Deacon Cc: Marc Zyngier Cc: Steven Price Cc: Suzuki K Poulose Cc: Catalin Marinas Cc: Jiri Pirko Cc: Jason Gunthorpe Cc: Mostafa Saleh Cc: Petr Tesarik Cc: Alexey Kardashevskiy Cc: Dan Williams Cc: Xu Yilun Aneesh Kumar K.V (Arm) (9): dma-direct: swiotlb: handle swiotlb alloc/free outside __dma_direct_alloc_pages dma-direct: use DMA_ATTR_CC_SHARED in alloc/free paths dma-pool: track decrypted atomic pools and select them via attrs dma: swiotlb: track pool encryption state and honor DMA_ATTR_CC_SHARED dma-mapping: make dma_pgprot() honor DMA_ATTR_CC_SHARED dma-direct: pass attrs to dma_capable() for DMA_ATTR_CC_SHARED checks dma-direct: make dma_direct_map_phys() honor DMA_ATTR_CC_SHARED dma-direct: set decrypted flag for remapped DMA allocations dma-direct: select DMA address encoding from DMA_ATTR_CC_SHARED arch/arm64/mm/init.c | 4 +- arch/x86/kernel/amd_gart_64.c | 30 +++--- arch/x86/kernel/pci-dma.c | 4 +- drivers/iommu/dma-iommu.c | 2 +- drivers/xen/swiotlb-xen.c | 9 +- include/linux/dma-direct.h | 19 +++- include/linux/dma-map-ops.h | 2 +- include/linux/swiotlb.h | 7 +- kernel/dma/direct.c | 189 ++++++++++++++++++++++++++-------- kernel/dma/direct.h | 32 +++--- kernel/dma/mapping.c | 16 ++- kernel/dma/pool.c | 154 +++++++++++++++++---------- kernel/dma/swiotlb.c | 93 +++++++++++++---- 13 files changed, 393 insertions(+), 168 deletions(-) base-commit: dd6c438c3e64a5ff0b5d7e78f7f9be547803ef1b -- 2.43.0