From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=115.124.30.133 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792489279; b=w0W1jIxAsO6TsS9EfMMAnSkx1tw+6mVDCpVnYGaSPMdGGwutxchqs+6ruyaJcrb6PR42 /a0MQa3s7RlmX5A50aQXwURFSS5t6qu6q8P1CJ9Sef0CYsOIIkCld0WWyMzWKqS0hgSWO GX1s7Uj4+/AcPPvNBKupCiPufuCMS2glyWPRKXfcrL9AmImsssccPF6g8BIeulXqt2FCp 59JRHkzpEB9Lpvws6G1vP1P0hF3n3+dzTJ/N9MR8YMCwP8WDgYXHwiaPV+PEkzp1lkzFO TMRdKYp1FkPBgh1+n9y2EyojAj4Q/E1ORCK2apgfn93VC1zbBQ1rRoRS44dl4EoXBww== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792489279; h=DMARC-Filter:DKIM-Signature:X-Alimail-AntiSpam:Received:From:To:Cc: Subject:Date:Message-Id:X-Mailer:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=kcaNBbiUMzKXzNSISjdYUCG67KZVrDK5XLEKTAvzTD8=; b=5eFlA4jB/WYXEWv7ZDZtuWFw7x6dSqvj8QD2cOF6L5bJatujX27T0Q9qu/s4L/bo5aY5 XnrydWE6nNa5gVTjZwgXsev0wMx8GiGhWOKuXbVoE4pL6tdoGq7m5v/ntciSE+6FxLl0v B1jmQMQX3pI2oXXaKZoqNz3CTgMJ082/9N0r/gJXNRHmAa5z55deKuIyz42GEhXprH6FX /hAK7e4xCOF7dyVcUgKRmayL8me0lvTtL8NqT9J5PXEAC8UcBvsQ3FvhiiWC4zcezNr1C XBy7dHw+y07acJiRP1z0Ws7LmfUnU4z3xEHWpFY0LI/J/h3MtBpFy9QpEkaPtRLORmA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=hnd9Hn8E; arc=none smtp.remote-ip=115.124.30.133 Received: from out30-133.freemail.mail.aliyun.com (out30-133.freemail.mail.aliyun.com [115.124.30.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4EC23606A31B for ; Tue, 20 Oct 2026 09:41:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 4EC23606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=hnd9Hn8E DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1792489276; h=From:To:Subject:Date:Message-Id:MIME-Version:Content-Type; bh=kcaNBbiUMzKXzNSISjdYUCG67KZVrDK5XLEKTAvzTD8=; b=hnd9Hn8EXWYYouXAjRHaPzeWZ9FNrXDV6wHWZhyezJoHCN/rluBc4hezKr+J22THL4gOrreiChGFGhWXH++mUE1J3ZrCto4nNnIJBn7mg1dlQlYw4ABXrIX6KYy6luayJBspeIIaG0Vj4ymV4IELjC01JhtAEryMfI1O0tRJuWk= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R181e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033045133197;MF=fangyu.yu@linux.alibaba.com;NM=1;PH=DS;RN=28;SR=0;TI=SMTPD_---0XDCspNU_1792489269; Received: from localhost.localdomain(mailfrom:fangyu.yu@linux.alibaba.com fp:SMTPD_---0XDCspNU_1792489269 cluster:ay36) by smtp.aliyun-inc.com; Tue, 20 Oct 2026 17:41:12 +0800 From: fangyu.yu@linux.alibaba.com To: tomasz.jeznach@linux.dev, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, baolu.lu@linux.intel.com, jroedel@suse.de, zong.li@sifive.com, andrew.jones@linux.dev, anup@brainfault.org, jgg@nvidia.com, jgg@ziepe.ca, kevin.tian@intel.com, atish.patra@linux.dev, skhawaja@google.com, vasant.hegde@amd.com, joerg.roedel@amd.com, tanchi25@mails.ucas.ac.cn, gong.shuai@sanechips.com.cn Cc: fangyu.yu@linux.alibaba.com, guoren@kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, kvm-riscv@lists.infradead.org Subject: [RFC PATCH v5 00/10] iommu/riscv: Add hardware dirty tracking for second-stage domains Date: Tue, 20 Oct 2026 17:40:56 +0800 Message-Id: <20261020094106.92722-1-fangyu.yu@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 (Apple Git-146) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Fangyu Yu The RISC-V IOMMU architecture defines an AMO_HWAD capability (Hardware Access/Dirty update) that allows the IOMMU to atomically set the A/D bits in second-stage PTEs on DMA access. When DC.tc.GADE is asserted, the IOMMU autonomously sets D on the first write to a page mapped by an iohgatp domain. This series wires that capability up to the iommufd dirty-tracking interface (IOMMU_HWPT_SET_DIRTY_TRACKING / IOMMU_HWPT_GET_DIRTY_BITMAP) and reports IOMMU_CAP_DIRTY_TRACKING. Design notes ------------ * The feature is scoped to second-stage (iohgatp) domains only; these are the domains created for KVM / VFIO device pass-through when userspace allocates an HWPT with IOMMU_HWPT_ALLOC_NEST_PARENT or IOMMU_HWPT_ALLOC_DIRTY_TRACKING. First-stage (iosatp) domains are not touched by this series. * The page-table side plugs into the existing generic_pt dirty hook framework (amdv1 / vtdss style). RISC-V adds the three required PTE ops – is_write_dirty / make_write_clean / make_write_dirty. Testing ------- * Test on QEMU RISC-V, a nvme and an e1000e device was passed through to an L2 guest via vfio-pci + iommufd. * generic_pt KUnit: the existing test_dirty case now runs and passes for the RISC-V 64-bit format. Follow-up work -------------- * Build a dedicated end-to-end test case that drives the full flow (HWPT_ALLOC with DIRTY_TRACKING -> attach -> IOAS_MAP -> generate real DMA -> SET_DIRTY_TRACKING -> GET_DIRTY_BITMAP -> verify bitmap against expected IOVA footprint) so that the behaviour can be regression-tested beyond the KUnit PTE-level coverage. * If possible, rebase and retest on top of the updated "iommu irqbypass" patchset. LLM-based coding assistants were used for code exploration, patch review, test execution, and drafting/editing messages and this cover letter. I reviewed and finalized all resulting code and text. --- Changes in v5: - Propagate the GADE bit from the new device context into the hardware DC in riscv_iommu_iodir_update(), so the pre-enabled GADE actually reaches the hardware. (Per Gong Shuai) - Issue a global IOTINVAL.GVMA in riscv_iommu_iodir_set_mode(), so that second-stage translations cached before a DDTP mode change (e.g. by a previous kernel after kexec) are flushed as the specification requires. (Per Tan Chi) - Rebased on top of v7.3, with [1] and [2] applied. - Link to v4: https://lore.kernel.org/linux-riscv/20260915032828.11250-1-fangyu.yu@linux.alibaba.com/ Changes in v4 (Jason's suggestions): - Rebased the series on top of [1] and [2]. - Drop the RISC-V-specific pt_num_items_lg2() top-level special case. - Validate page-table address widths by translation stage: accept only Sv39/Sv48/Sv57 widths for first-stage tables and only Sv39x4/Sv48x4/ Sv57x4 widths for second-stage tables. - Replace the aliased first-stage/second-stage MODE union with independent FSC/IOSATP and IOHGATP MODE fields. - Add pt_dirty_supported() to restrict RISC-V generic_pt dirty tracking to second-stage tables. - Link to v3: https://lore.kernel.org/linux-riscv/20260821132749.82070-1-fangyu.yu@linux.alibaba.com/ Changes in v3 (Andrew Jones's suggestions): - Rebased the series on top of Andrew Jones' generic_pt RISC-V supported feature mask fix, which adds PT_FEAT_RISCV_SVPBMT to the supported feature set. - Added PT_FEAT_RISCV_S2 to the RISC-V generic_pt supported feature mask and KUnit feature matrix. - Kept PT_FEAT_SIGN_EXTEND only for first-stage RISC-V KUnit configs; second stage configs now use PT_FEAT_RISCV_S2 without sign-extension semantics. - Split RISC-V IOMMU capability checks into first-stage FSC and second-stage IOHGATP helpers. - Updated second-stage paging domain setup to use GPA widths 41/50/59 and to avoid PT_FEAT_SIGN_EXTEND. - Link to v2: https://lore.kernel.org/linux-riscv/20260507113706.11400-1-fangyu.yu@linux.alibaba.com/ Changes in v2 (Jason's suggestions): - Introduced a single PT_FEAT_RISCV_S2: second-stage selection is driven purely by this feature bit. - Switched from dynamic DC.tc.GADE toggling to static pre-enable. - domain_alloc_paging_flags: follow the switch/case design from other drivers. - Drop IOMMU_CAP_DEFERRED_FLUSH in riscv_iommu_capable. - Remove the .hw_info-related patch. - Link to v1: https://lore.kernel.org/linux-riscv/20260428131359.34872-1-fangyu.yu@linux.alibaba.com/ [1] https://lore.kernel.org/linux-iommu/1-v2-563ee63886f0+1209-iommupt_armv8_jgg@nvidia.com/ [2] https://lore.kernel.org/linux-iommu/20260818092444.42755-1-andrew.jones@oss.qualcomm.com/ Fangyu Yu (6): iommupt: Add RISC-V Second-stage (iohgatp) page table support iommupt: Add RISC-V dirty tracking PTE ops iommu/riscv: Add domain_alloc_paging_flags for second-stage domain iommu/riscv: Pre-enable GADE for second-stage domains iommu/riscv: Add dirty tracking support for second-stage domains iommu/riscv: Add IOTINVAL.GVMA invalidations Tomasz Jeznach (2): iommu/riscv: report iommu capabilities RISC-V: KVM: Enable KVM_VFIO interfaces on RISC-V arch Zong Li (2): iommu/riscv: use data structure instead of individual values iommu/riscv: support GSCID and GVMA invalidation command arch/riscv/kvm/Kconfig | 2 + drivers/iommu/generic_pt/fmt/iommu_riscv64.c | 2 +- drivers/iommu/generic_pt/fmt/riscv.h | 158 +++++++++++-- drivers/iommu/riscv/iommu-bits.h | 7 + drivers/iommu/riscv/iommu.c | 235 +++++++++++++++---- include/linux/generic_pt/common.h | 4 + include/linux/generic_pt/iommu.h | 11 + 7 files changed, 347 insertions(+), 72 deletions(-) -- 2.50.1