From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f46.google.com (mail-wr1-f46.google.com [209.85.221.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 68A804EA393 for ; Wed, 14 Oct 2026 09:37:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791970675; cv=none; b=bJp0PSv60eU3VwwdUGq12jC3Frxz38inIhoM5xR9VEZkxQFZukFoVxvy59WjrFSuK9fhkxbaoWtvj8RauNRCcWLzji8eGR/6SA+/H321nTCnzkX9BEH4/Dq4GyW6E+vVolNSe+JeMLmTk3oPp3JMoD6wn+45SIyGvKPMot+geQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791970675; c=relaxed/simple; bh=am0hAA/nRejPE4sLTQ21BeEMerAqyBcR4Wmfr7+mp98=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fseER5MT2Co2sKPGnw8WlY1q2yXcF3gJ/gp0GAFKGToX0NrMyjJu4Z4ktAqim9MtTpNeitBIaDfXQlXrZODogIbby36L2kufj9/InMQtY+t7enzbZt50wiQTMhRvtz++xG/2gc6vEjJW4hFLN8l9HAP+JouIwBEMNicCVoZ26uY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=EwznDaKh; arc=none smtp.client-ip=209.85.221.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EwznDaKh" Received: by mail-wr1-f46.google.com with SMTP id ffacd0b85a97d-48b060ec084so2529346f8f.0 for ; Wed, 14 Oct 2026 02:37:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791970666; x=1792575466; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=XH1DvjtQ4kSOTYVjVn8rMjarIlp6Ws3f/rSFMl2hKxs=; b=EwznDaKhPpvGXxLe7BB+ZcRRK4E1o996vzalW+r/N6Jiq7nX8vwcixiCQQ4nGBIs72 Moe0ahffzZUAWejfBNx6Vf3kfXH8LMc2jZ3mteP6qysZSPJEhlFuZz8pvKVmz/ltu7AD vPzaYRQcTZN56u6t7Dk7WrwI/uIrjUs5GeFezMG/jy1S0CV0NjilZ0yeLS74JCq/D9io DcJCTnBUpnLm0KE6y5pifLxC9uiLCTG2Ixc3eu+A2WJbsRZPXiRUs3PpYDhPrwVz1p+e 7ikoeIEc9MIoY7jLe+IuCaCX3SGkCCww9gaIkPwCzmGo/v4amQ3NMAeUjP+gW+lOPr9P wbgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791970666; x=1792575466; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=XH1DvjtQ4kSOTYVjVn8rMjarIlp6Ws3f/rSFMl2hKxs=; b=1YSkK88l0ey5D6tBJDadJbEZ6h3oWjOuaYMF2PzUl9j4+53NZOvlVNj8R27YMS0oFR giPiHE/Zyh5JnUyghXiqeQyLrXAUO6QHoZO5nzD5TAO/GvRg81Pe9YwcIW3NZIKsCdzv aAL5O06kMypLE/wDA1ZxUGBJc+zBFJGW96M3CukqUZuYoAQSU62gRe8/eLCYGF+tp6PS iNDNHwx3G2HEeQC3yYfCslk8Qv7TLBvkJeujcy3yPdSCyMk534FUFkupOTL00PMlYYtR Opd3xy3TGFqBdhz5w16/AmRzJm8XJwyJsAGT4PmkVZE7geHeBNWG8jc3S2ZnQzSsUv2U AFug== X-Forwarded-Encrypted: i=1; AKwUvBzdr5cT+VVxHG65Uo1UqUBdTUUI1AYafVwwcIJywtgZi2uSYmlx8ll9bZCAfbCQX3Nr3m+SuJMtPZtVjTJM@vger.kernel.org X-Gm-Message-State: AFq9FYJ4H3w2eBtXBM2HlQV7djihBW/xSbojBW00qIGfKW8coZ02WcIL /U+gCtdWks7zi4Dg3Tp38FLYrAzSQIE4pgyNE7iJh+pJMX2HQWoFQ6pZ X-Gm-Gg: AYBFou03jvW24GGeMBblD6z3/6FuoTx3zOUPEyXyVjE+AnAfGKuCYg7JMoufGGwfjf8 km++nZ4BEKYhRzWc3IGivQNUeg9rT/6GMeaasiAbKqyXryM5TSrQJD9BT60B29/oY2yt+6eHL11 5Iq9itulr1ajgoN82SP/o+IHW5sMLPaPVHac02UxLug6pr0O6uZRHUnFnD1b9LX4R/OyBaLtVkt gb74R+9+++PG2mfC3ZhPi+KVwRF06NpXPBJNdmYyCJE2KXUv125bR0U8V1KavPmlBuBA0g4UDe+ 2cpQS+yBVsrdOlf/KL942npS63u0bJ1IxalHRm2UjLRN6/7GrXfqL6dPBOM7gki+SQkTmrR9okc UsUZemL/SnL9ecjGnMtEiQzVzLWkWHyA0ygvN5M96/k0d2gFxlul25+fqo+u/mzCC3EEaPevImW dmRpyYwjn4uuB3zT3ZPgdkMLypUBmeFw31NphG00e/lL51n++yvUCkQXNhxIwgcIey39x1QmzrI BZhHsbClfkfDBNcfxUseM857yugXnT8hb5+oL9PtMtO9mzsABdX7Si82Vf9rHV6iZl1boirK+iK XVnxNL66pTSlHwubM+otj2icC8nIR3MlamdF X-Received: by 2002:adf:e001:0:20b0:48b:efb:4a66 with SMTP id ffacd0b85a97d-48dba7b405bmr21828342f8f.6.1791970666161; Wed, 14 Oct 2026 02:37:46 -0700 (PDT) Received: from dev-dsk-fgriffo-1c-93421965.eu-west-1.amazon.com (54-240-197-234.amazon.com. [54.240.197.234]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-48de3f7f8b8sm9365477f8f.35.2026.10.14.02.37.45 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 14 Oct 2026 02:37:45 -0700 (PDT) From: Fred Griffoul To: Paolo Bonzini , Sean Christopherson , Marc Zyngier , Oliver Upton , Catalin Marinas , Andrew Morton , David Hildenbrand , Alexander Viro , Christian Brauner , Jan Kara , Jason Gunthorpe , Kevin Tian , Joerg Roedel , Will Deacon , Robin Murphy , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Jonathan Corbet , Shuah Khan , Shuah Khan Cc: David Woodhouse , Ackerley Tng , "Aneesh Kumar K . V" , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Steffen Eiden , linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org Subject: [RFC PATCH v2 08/11] iommufd/selftest: Add mock-domain IOVA queries Date: Wed, 14 Oct 2026 09:37:30 +0000 Message-ID: <20261014093733.90312-9-griffoul@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261014093733.90312-1-griffoul@gmail.com> References: <20261014093733.90312-1-griffoul@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Fred Griffoul A test of memory that can be taken back or replaced does not know in advance which frame a device reaches. IOMMU_TEST_OP_MD_CHECK_MAP only compares against a known buffer. Add MD_CHECK_MAPPED, which checks that a range is fully mapped or fully unmapped, and MD_IOVA_TO_PHYS, which returns the frame behind an IOVA, or 0 if it is unmapped. Both refuse an IOVA outside the domain's aperture. Both hold domains_rwsem for writing so that a userspace unmap cannot free a page-table level during the walk. Assisted-by: Claude:claude-opus-5-5 Signed-off-by: Fred Griffoul --- drivers/iommu/iommufd/iommufd_test.h | 16 ++++ drivers/iommu/iommufd/selftest.c | 109 +++++++++++++++++++++++++++ 2 files changed, 125 insertions(+) diff --git a/drivers/iommu/iommufd/iommufd_test.h b/drivers/iommu/iommufd/iommufd_test.h index 52b78cbcc920..28fd9c43edc4 100644 --- a/drivers/iommu/iommufd/iommufd_test.h +++ b/drivers/iommu/iommufd/iommufd_test.h @@ -31,6 +31,8 @@ enum { IOMMU_TEST_OP_PASID_CHECK_HWPT, IOMMU_TEST_OP_DMABUF_GET, IOMMU_TEST_OP_DMABUF_REVOKE, + IOMMU_TEST_OP_MD_CHECK_MAPPED, + IOMMU_TEST_OP_MD_IOVA_TO_PHYS, }; enum { @@ -193,6 +195,20 @@ struct iommu_test_cmd { __s32 dmabuf_fd; __u32 revoked; } dmabuf_revoke; + struct { + /* + * 1: every page in [iova, iova+length) must be mapped; + * 0: none of them may be. Mixed is an error. + */ + __u32 mapped; + __u32 __reserved; + __aligned_u64 iova; + __aligned_u64 length; + } check_mapped; + struct { + __aligned_u64 iova; + __aligned_u64 out_phys; /* 0 if unmapped */ + } iova_to_phys; }; __u32 last; }; diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index af07c642a526..1f5cd2d00fda 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -2031,6 +2031,107 @@ static int iommufd_test_dmabuf_get(struct iommufd_ucmd *ucmd, return rc; } +/* + * True if [iova, iova + length) lies inside the domain's aperture. Outside + * it the page table returns an error code from iova_to_phys(), not 0. + */ +static bool mock_domain_covers(struct mock_iommu_domain *mock, + unsigned long iova, size_t length) +{ + struct iommu_domain_geometry *geo = &mock->domain.geometry; + unsigned long last; + + if (check_add_overflow(iova, length - 1, &last)) + return false; + return iova >= geo->aperture_start && last <= geo->aperture_end; +} + +/* + * iova_to_phys() walks the page table, so it must not run while an unmap + * frees a level of it. A userspace unmap holds the IOAS domains_rwsem for + * reading while it unmaps the domains, so holding it for writing keeps such + * unmaps away. A memory provider or dma-buf revoke unmaps under its pages + * mutex only, so tests must not run these queries while a revoke of the + * range is in progress. + */ +static struct rw_semaphore * +mock_domain_unmap_lock(struct iommufd_hw_pagetable *hwpt) +{ + return &to_hwpt_paging(hwpt)->ioas->iopt.domains_rwsem; +} + +/* + * Report the physical address the mock domain resolves @iova to, or 0 if + * it is unmapped. Lets a test check that two IOVAs share one frame, or that + * an IOVA moved to another frame, without knowing the frames in advance. + */ +static int iommufd_test_md_iova_to_phys(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, + unsigned long iova) +{ + struct iommu_test_cmd *cmd = ucmd->cmd; + struct iommufd_hw_pagetable *hwpt; + struct mock_iommu_domain *mock; + unsigned int page_size; + int rc; + + hwpt = get_md_pagetable(ucmd, mockpt_id, &mock); + if (IS_ERR(hwpt)) + return PTR_ERR(hwpt); + + page_size = 1 << __ffs(mock->domain.pgsize_bitmap); + if (iova % page_size || !mock_domain_covers(mock, iova, page_size)) { + rc = -EINVAL; + goto out_put; + } + down_write(mock_domain_unmap_lock(hwpt)); + cmd->iova_to_phys.out_phys = + mock->domain.ops->iova_to_phys(&mock->domain, iova); + up_write(mock_domain_unmap_lock(hwpt)); + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); +out_put: + iommufd_put_object(ucmd->ictx, &hwpt->obj); + return rc; +} + +static int iommufd_test_md_check_mapped(struct iommufd_ucmd *ucmd, + unsigned int mockpt_id, + unsigned long iova, size_t length, + bool mapped) +{ + struct iommufd_hw_pagetable *hwpt; + struct mock_iommu_domain *mock; + unsigned int page_size; + int rc = 0; + + hwpt = get_md_pagetable(ucmd, mockpt_id, &mock); + if (IS_ERR(hwpt)) + return PTR_ERR(hwpt); + + page_size = 1 << __ffs(mock->domain.pgsize_bitmap); + if (iova % page_size || length % page_size || !length || + !mock_domain_covers(mock, iova, length)) { + rc = -EINVAL; + goto out_put; + } + + down_write(mock_domain_unmap_lock(hwpt)); + for (; length; length -= page_size, iova += page_size) { + bool is_mapped = + mock->domain.ops->iova_to_phys(&mock->domain, iova) != 0; + + if (is_mapped != mapped) { + rc = -ENOENT; + break; + } + } + up_write(mock_domain_unmap_lock(hwpt)); + +out_put: + iommufd_put_object(ucmd->ictx, &hwpt->obj); + return rc; +} + static int iommufd_test_dmabuf_revoke(struct iommufd_ucmd *ucmd, int fd, bool revoked) { @@ -2143,6 +2244,14 @@ int iommufd_test(struct iommufd_ucmd *ucmd) return iommufd_test_dmabuf_revoke(ucmd, cmd->dmabuf_revoke.dmabuf_fd, cmd->dmabuf_revoke.revoked); + case IOMMU_TEST_OP_MD_CHECK_MAPPED: + return iommufd_test_md_check_mapped(ucmd, cmd->id, + cmd->check_mapped.iova, + cmd->check_mapped.length, + cmd->check_mapped.mapped); + case IOMMU_TEST_OP_MD_IOVA_TO_PHYS: + return iommufd_test_md_iova_to_phys(ucmd, cmd->id, + cmd->iova_to_phys.iova); default: return -EOPNOTSUPP; } -- 2.47.3