From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34A3FC54ED1 for ; Fri, 23 May 2025 15:45:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C74156B00CF; Fri, 23 May 2025 11:45:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C24986B00D0; Fri, 23 May 2025 11:45:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B3A936B00D1; Fri, 23 May 2025 11:45:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 960E46B00CF for ; Fri, 23 May 2025 11:45:17 -0400 (EDT) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 4516D808E8 for ; Fri, 23 May 2025 15:45:17 +0000 (UTC) X-FDA: 83474596674.11.78648A2 Received: from NAM10-MW2-obe.outbound.protection.outlook.com (mail-mw2nam10on2058.outbound.protection.outlook.com [40.107.94.58]) by imf18.hostedemail.com (Postfix) with ESMTP id 36E591C0005 for ; Fri, 23 May 2025 15:45:13 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=sZsHUsIt; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of ankita@nvidia.com designates 40.107.94.58 as permitted sender) smtp.mailfrom=ankita@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1748015114; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references:dkim-signature; bh=+U5BmXBCwXq7dcG8dVOYzzidUz4anQB0juElHap6PK4=; b=fd+xQQddPftwHMPXZaUmESDe2zOQzayArVvgae5YbLi76m2D8ONVu7jIJLtsdrJGkDTy0B 5YgbexkbRyYNLGcOyzya9FXg2LqwGWzZT7zyEMApqSZM1KTEksWKcAtl11rCsOF9Av/ZTj dYyIdml16LSDszvr51GW6HB5JUf2O8Y= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1748015114; a=rsa-sha256; cv=pass; b=lOsgwRSYnhHknMsDRKy/vR3CgTmj/RzU6/kXBh2+ZEnVGKHgBEbnsXPc967YV5BvNCQ4J/ OayX2V33v7Bk24HjOviPd2M0Ms1YCpLCu1dZ1w7r4suzC9clLGsm0vevU8YOllsGpTDC3t po88xVai79+kUdEk7vz9FAhz0x3ATbs= ARC-Authentication-Results: i=2; imf18.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=sZsHUsIt; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf18.hostedemail.com: domain of ankita@nvidia.com designates 40.107.94.58 as permitted sender) smtp.mailfrom=ankita@nvidia.com; dmarc=pass (policy=reject) header.from=nvidia.com ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=amlZ2QZ3Eomwv+WqeENGPkHducBhJ8suGqqGAcyAFm9zcr3gT81+TzkAw+XGxX0sh/O+V5+3VMXUPjoimwha1m0WzsvaK8NeE6DCefI/vGcSC6QWscTiwX6srknEazpRGTzc3pQRqRQGFdDfjfoKaFrECIVY5kCq3zQk5pl+M00NsfuZ995S/Up1hKyCc/4YXR7LXqPO08mvRKU0Gx4HuM6DvO3elBZwstPF31U0VUNKl7V5LuS+sDJ9EHy2CFZPnOPJak6TWcTVqFnZtLhSP2G/gDYHYGNHJBJ0fHs6BjfuivHlpNqvnI9A0QPZk1TQ4qrIBvJs0SO2SzwGP4UD2w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=+U5BmXBCwXq7dcG8dVOYzzidUz4anQB0juElHap6PK4=; b=NeDxPG03gxnibkBcKjAMqzY7N2bD+FowVUPZhwkL1hXHTqTsg9ooViUSQScei2yhZ44GcCApBI66DwgroWpoTBixa/5hhfXa1hwkAMIVnElFNycv8GUTIgYuOPuLh6iPvtiG44+82gCQ49SRiNH63Kp+yjhbEotEi3KNvjlFzL7LQaBNOkIU+6xER+oNC9Y9QrzIOsohI64m4eC2Xbv9b8FJE3QousXV7R3Pe+vMwx4k38xewuH6fJidQh02GqgZzIe13QDcYKOAmw8I7M+VRE5BbnZ0nkEf31vGqTS3/MswKgxY+ObR2zXVBVVqYhYKd89dldKSvKm28Q42LPPzyg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 216.228.118.233) smtp.rcpttodomain=redhat.com smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none (0) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=+U5BmXBCwXq7dcG8dVOYzzidUz4anQB0juElHap6PK4=; b=sZsHUsItHlwBjVYrOOF5n/ZLszufAntgb26LP/TjLhsvEWNyubIIaAcJ0xttqKXVtjQzsOGKcedLdOEfyqoocpaVsUPaCuO9adiqrxvromEmVawig1bkIipF2tV30TvXJC8KO9n6ah0Yv59GKf1ljdA62m7YddvlG+FhXKtklSspBZQc5uh8GowY9nbKAqoIP7V+U+xdnxTOah4pQUCAhCTk5j1upSO19y3pZ8FrQEzZye+S98P7lral07HPGVA9Mu5nML6BEfVmRgA1B83Xwg7fQPUffv7tWB8uSRjD2N+OMYdqyHD5YTEUgB2fmmhgQ9UWqv0yQhmg/GsT9yOfqw== Received: from BN9PR03CA0434.namprd03.prod.outlook.com (2603:10b6:408:113::19) by DS0PR12MB9348.namprd12.prod.outlook.com (2603:10b6:8:1a0::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8769.24; Fri, 23 May 2025 15:45:10 +0000 Received: from BN1PEPF00004685.namprd03.prod.outlook.com (2603:10b6:408:113:cafe::53) by BN9PR03CA0434.outlook.office365.com (2603:10b6:408:113::19) with Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384) id 15.20.8746.31 via Frontend Transport; Fri, 23 May 2025 15:45:10 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 216.228.118.233) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 216.228.118.233 as permitted sender) receiver=protection.outlook.com; client-ip=216.228.118.233; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (216.228.118.233) by BN1PEPF00004685.mail.protection.outlook.com (10.167.243.86) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8769.18 via Frontend Transport; Fri, 23 May 2025 15:45:10 +0000 Received: from drhqmail202.nvidia.com (10.126.190.181) by mail.nvidia.com (10.127.129.6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.4; Fri, 23 May 2025 08:44:46 -0700 Received: from drhqmail201.nvidia.com (10.126.190.180) by drhqmail202.nvidia.com (10.126.190.181) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14; Fri, 23 May 2025 08:44:45 -0700 Received: from localhost.nvidia.com (10.127.8.12) by mail.nvidia.com (10.126.190.180) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.14 via Frontend Transport; Fri, 23 May 2025 08:44:45 -0700 From: To: , , , , , , , , , , , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH v5 0/5] KVM: arm64: Map GPU device memory as cacheable Date: Fri, 23 May 2025 15:44:40 +0000 Message-ID: <20250523154445.3779-1-ankita@nvidia.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-NV-OnPremToCloud: AnonymousSubmission X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BN1PEPF00004685:EE_|DS0PR12MB9348:EE_ X-MS-Office365-Filtering-Correlation-Id: 0b585a95-d0d5-48bb-70a7-08dd9a10ccb9 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|36860700013|82310400026|1800799024|376014|7416014|921020|13003099007; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?gnLNWLOHFq6cc3oJ/97PTbcRgYeZ8flik1gIzBdW9VyjOJPoCzdLqVVVYXVq?= =?us-ascii?Q?YweLzTmEruQchGRlVX3z+1QkH5xTKJiN0/0Hpml37kqZJOJ17cgmkgi+/p/l?= =?us-ascii?Q?9Oom8BR3NwTlMDBUhRkCbBjQg+kjnxzcXkxhEiKyddrhWDpEG8tpCWokQj3U?= =?us-ascii?Q?ICzFnw8NlgVKoC62Tf4Y4iLLsClJ6854N0RHqa16Q/w7DT99bE/z96lUiLh2?= =?us-ascii?Q?OnEPsXHKJFI9s4ILEmVJc/NdHabPQjmbXk/Jrh6vHOAFDmi+QAcF+ztNtIog?= =?us-ascii?Q?0exNPxAaFgEwWK+Hshec5SKHhqbO6I1pfxhDCePtbuKo9RhK95zEHrMDhETK?= =?us-ascii?Q?V/2/Xpcmj4725KiUfqbBa9fxSR6zNZt6t7OCtLxwxszIYcGQS+BoMYrI+qlJ?= =?us-ascii?Q?edI4G10jlsGAA9iUC7vZCmWTnWk8TLyisB8Hj6bBHbgmnUDac7B4TBsJpk+k?= =?us-ascii?Q?cHUcqkCy/BVaEPq6O/ntoOKHcYRjtTjmVxDszPmLSDWCLIv9SoIXTrbWlWvh?= =?us-ascii?Q?wSVCE8lTGELAYi/Tpp2qXCZBwt2JQvslJQaY+BjSsRUm/YG1SNQWesLjAAp2?= =?us-ascii?Q?BH4i4MmFzFW/GRdvPqisjAzN4cYCRaHo/O3QUx2hZCOz8oFndHmDC6EmvArK?= =?us-ascii?Q?u+ke8y4fUnVor8Oc/fmZRrqLlpiSuWq9q0KJxwdSYbX1vL2/3QXG1gV25htu?= =?us-ascii?Q?uAeAd36bTQV4dGI/hfb00e5DiipCuPSHnPIT2eLR3VysxDrTR8DnU2SGorgm?= =?us-ascii?Q?7y8INA3DfzITamHEsPzzLnl82ZeEQl0yY3wPjR0yaneIB7OoZSs6XHnrS0vh?= =?us-ascii?Q?m9wHS25URuWg1/hGm0LJ84Aa1bDeRdY/A1cCUAiyYyzsvhx7zQJGdxRRyIp3?= =?us-ascii?Q?dfrk4H4VoPaDVg+aULvKNrksbgEwkC2SZoSKAd3/8pe45glbAn82PO8cQg79?= =?us-ascii?Q?DXouAHp0ff2PuvGStmN7ej5IOTOlxDW3YPRpvD34F/hW+3PyKJw6UNZBgvZZ?= =?us-ascii?Q?LCT6lwgq+vq6docmXD2YsYfz2d5dreX+xJZFBkYRtVPAGS5s4Vg7aD1ZzV3A?= =?us-ascii?Q?OIHqw0pDAMVQu/FKgEwhTgrjx+CQqBOdBegxiE/l4Ni2wRtmWCUZeFL2jn06?= =?us-ascii?Q?P8lJRMUNqXOuvNiTr9s4JyENvz4YftulsYPFOJs4E0JYhHpl38CafiQI3r1b?= =?us-ascii?Q?YKD8CN8htTzal5LaqKwNYrluB6jizuAViigfqSsXD+DQ7fe/c2m4+AuPnSvF?= =?us-ascii?Q?xa02rGKYZ2FDOovT2UBhOvpBKl4LYaKrauyFdJXRBgBQHpxm1q7FUbF2lbEG?= =?us-ascii?Q?zP7oCTEXGvf6uhjzclcauV4OsuuE/ot4FBfI5j5RiU6E+ldXqteypDQQpCws?= =?us-ascii?Q?gCH7xi04ET0k3WgKhBMzB95CausdpXQCYSx1bZzFczp8Tqx6yXf+JlA6ZE4z?= =?us-ascii?Q?i9tO3XmiFQu4Sk/VydS1EnPapUme1iaawifrZW3y05iGhs3XwsOeqYAi7TRa?= =?us-ascii?Q?aKTXhjfFwJ/F4c0s8nOPP2TArKBpj34zz18cqbU4axqz6o+2ELUkP4PROgx9?= =?us-ascii?Q?6lQLDuy4WYBYf0BiT3Q=3D?= X-Forefront-Antispam-Report: CIP:216.228.118.233;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:dc7edge2.nvidia.com;CAT:NONE;SFS:(13230040)(36860700013)(82310400026)(1800799024)(376014)(7416014)(921020)(13003099007);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 23 May 2025 15:45:10.0476 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 0b585a95-d0d5-48bb-70a7-08dd9a10ccb9 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.118.233];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: BN1PEPF00004685.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR12MB9348 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 36E591C0005 X-Stat-Signature: z95codezj9a5r6pyxc7booqf9mkckh9z X-Rspam-User: X-HE-Tag: 1748015113-754691 X-HE-Meta: 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 p8eeUQDN 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ankit Agrawal Grace based platforms such as Grace Hopper/Blackwell Superchips have CPU accessible cache coherent GPU memory. The GPU device memory is essentially a DDR memory and retains properties such as cacheability, unaligned accesses, atomics and handling of executable faults. This requires the device memory to be mapped as NORMAL in stage-2. Today KVM forces the memory to either NORMAL or DEVICE_nGnRE depending on whether the memory region is added to the kernel. The KVM code is thus restrictive and prevents device memory that is not added to the kernel to be marked as cacheable. The patch aims to solve this. A cachebility check is made if the VM_PFNMAP is set in VMA flags by consulting the VMA pgprot value. If the pgprot mapping type is cacheable, it is considered safe to be mapped cacheable as the KVM S2 will have the same Normal memory type as the VMA has in the S1 and KVM has no additional responsibility for safety. Note when FWB (Force Write Back) is not enabled, the kernel expects to trivially do cache management by flushing the memory by linearly converting a kvm_pte to phys_addr to a KVA. The cache management thus relies on memory being mapped. Since the GPU device memory is not kernel mapped, exit when the FWB is not supported. Similarly, ARM64_HAS_CACHE_DIC allows KVM to avoid flushing the icache and turns icache_inval_pou() into a NOP. So the cacheable PFNMAP is made contingent on these two hardware features. The ability to safely do the cacheable mapping of PFNMAP is exposed through a KVM capability. The userspace is supposed to query it and consequently set a new memslot flag if it desire to do such mapping. The changes are heavily influenced by the discussions among maintainers Marc Zyngier and Oliver Upton besides Jason Gunthorpe, Catalin Marinas, David Hildenbrand, Sean Christopherson [1] in v3. Many thanks for their valuable suggestions. Applied over next-20250407 and tested on the Grace Hopper and Grace Blackwell platforms by booting up VM, loading NVIDIA module [2] and running nvidia-smi in the VM. To run CUDA workloads, there is a dependency on the IOMMUFD and the Nested Page Table patches being worked on separately by Nicolin Chen. (nicolinc@nvidia.com). NVIDIA has provided git repositories which includes all the requisite kernel [3] and Qemu [4] patches in case one wants to try. v4 -> v5 1. Invert the check to allow MT_DEVICE_* or NORMAL_NC instead of disallowing MT_NORMAL in 1/5. (Catalin Marinas) 2. Removed usage of stage2_has_fwb and directly using the FWB cap check. (Oliver Upton) 3. Introduced kvm_arch_supports_cacheable_pfnmap to check if the prereq features are present. (David Hildenbrand) v3 -> v4 1. Fixed a security bug due to mismatched attributes between S1 and S2 mapping to move it to a separate patch. Suggestion by Jason Gunthorpe (jgg@nvidia.com). 2. New minor patch to change the scope of the FWB support indicator function. 3. Patch to introduce a new memslot flag. Suggestion by Oliver Upton (oliver.upton@linux.dev) and Marc Zyngier (maz@kernel.org) 4. Patch to introduce a new KVM cap to expose cacheable PFNMAP support. Suggestion by Marc Zyngier (maz@kernel.org). 5. Added checks for ARM64_HAS_CACHE_DIC. Suggestion by Catalin Marinas (catalin.marinas@arm.com) v2 -> v3 1. Restricted the new changes to check for cacheability to VM_PFNMAP based on David Hildenbrand's (david@redhat.com) suggestion. 2. Removed the MTE checks based on Jason Gunthorpe's (jgg@nvidia.com) observation that it already done earlier in kvm_arch_prepare_memory_region. 3. Dropped the pfn_valid() checks based on suggestions by Catalin Marinas (catalin.marinas@arm.com). 4. Removed the code for exec fault handling as it is not needed anymore. v1 -> v2 1. Removed kvm_is_device_pfn() as a determiner for device type memory determination. Instead using pfn_valid() 2. Added handling for MTE. 3. Minor cleanup. Link: https://lore.kernel.org/all/20250310103008.3471-1-ankita@nvidia.com [1] Link: https://github.com/NVIDIA/open-gpu-kernel-modules [2] Link: https://github.com/NVIDIA/NV-Kernels/tree/6.8_ghvirt [3] Link: https://github.com/NVIDIA/QEMU/tree/6.8_ghvirt_iommufd_vcmdq [4] v4 Link: Link: https://lore.kernel.org/all/20250310103008.3471-1-ankita@nvidia.com Ankit Agrawal (5): KVM: arm64: Block cacheable PFNMAP mapping KVM: arm64: New function to determine hardware cache management support kvm: arm64: New memslot flag to indicate cacheable mapping KVM: arm64: Allow cacheable stage 2 mapping using VMA flags KVM: arm64: Expose new KVM cap for cacheable PFNMAP Documentation/virt/kvm/api.rst | 17 ++++++++- arch/arm64/kvm/arm.c | 7 ++++ arch/arm64/kvm/mmu.c | 70 +++++++++++++++++++++++++++++++++- include/linux/kvm_host.h | 2 + include/uapi/linux/kvm.h | 2 + virt/kvm/kvm_main.c | 11 +++++- 6 files changed, 105 insertions(+), 4 deletions(-) -- 2.34.1