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 88C4BCD493B for ; Thu, 21 Sep 2023 01:49:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1F3C06B01AE; Wed, 20 Sep 2023 21:49:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1A4856B01F0; Wed, 20 Sep 2023 21:49:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F37E06B01F1; Wed, 20 Sep 2023 21:49:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id DF6C36B01AE for ; Wed, 20 Sep 2023 21:49:30 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id B22541A0256 for ; Thu, 21 Sep 2023 01:49:30 +0000 (UTC) X-FDA: 81258922500.06.29F5E9F Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.93]) by imf24.hostedemail.com (Postfix) with ESMTP id C6443180009 for ; Thu, 21 Sep 2023 01:49:25 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=NmudNnXX; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf24.hostedemail.com: domain of yan.y.zhao@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yan.y.zhao@intel.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1695260967; h=from:from:sender:reply-to: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=+3aC1OVXl10q8xdpDYGn6D2IOakpCQbxwk421apnZV0=; b=isA3vTI+18wJtuV2qib+fRXEO04m4EYxX1FQ70rtPJjaoHctaqW/QIbZH1SOsoOE2uYZwL FaiV3Xh/olsJam92m18VD3jIlNmc5TVuDc/sRW58VovSsLDfjP54h8gw1Svb8475KXQtvT LZeys2xFmJs4q8vmVFTCuziHa5tBsrQ= ARC-Authentication-Results: i=2; imf24.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=NmudNnXX; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); spf=pass (imf24.hostedemail.com: domain of yan.y.zhao@intel.com designates 192.55.52.93 as permitted sender) smtp.mailfrom=yan.y.zhao@intel.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1695260967; a=rsa-sha256; cv=fail; b=M6lK2W/QO9W0QcYf9sL7BLzg1/Wdi0Q2FWYeEgr9iw0YcBGq6qASLPZuVV7MR914W7R8K0 Ors8YS6ZQK/Cws53qP0/rAAIFWIor13vqNDkHn/xZE7dNV0ljU4ZZiseqqUc6eFVL9Imo/ xIZmCfU2U4tePQgiuQDxhr4QVgvRnII= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695260965; x=1726796965; h=date:from:to:cc:subject:message-id:reply-to:references: in-reply-to:mime-version; bh=ybsMtUIUFSJoctpzBY42mYJCdPhjUqrVHUheuTnnJAM=; b=NmudNnXXIHMsrQldTM4AvrOzP8MzJlO2D5XHb06QLXMu8Sgyh8BsZO09 U3IdUFozBmGU70fXqMZkpKYgBW4gY11zbz7/wrwgZkFlFBxCQ5BekoBLF bvw+vCEMLJC8lsrFqZ3+RdnKRxdRez17FRAbtibXXMG0pHLqQYxhRATk8 VP3jqIzFJfBlz/o9qjuFhnYaHHihc4OLXQPRip4YPjuNu2ixG7/gZvv3v mGUsDIh1A8DW0fiERT6FZh6P2QB3icRjkh4j1/eR6Em7fq1CudIzvud9y kfFNxHqXHo/73Aa6zVUNaClQFs4/u1bQLG9AZ9BivNuXuT3MhBQ0wI77p w==; X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="377688684" X-IronPort-AV: E=Sophos;i="6.03,164,1694761200"; d="scan'208";a="377688684" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2023 18:49:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="817156551" X-IronPort-AV: E=Sophos;i="6.03,164,1694761200"; d="scan'208";a="817156551" Received: from orsmsx602.amr.corp.intel.com ([10.22.229.15]) by fmsmga004.fm.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 20 Sep 2023 18:49:21 -0700 Received: from orsmsx612.amr.corp.intel.com (10.22.229.25) by ORSMSX602.amr.corp.intel.com (10.22.229.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.32; Wed, 20 Sep 2023 18:49:21 -0700 Received: from orsmsx612.amr.corp.intel.com (10.22.229.25) by ORSMSX612.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.32; Wed, 20 Sep 2023 18:49:20 -0700 Received: from ORSEDG601.ED.cps.intel.com (10.7.248.6) by orsmsx612.amr.corp.intel.com (10.22.229.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.32 via Frontend Transport; Wed, 20 Sep 2023 18:49:20 -0700 Received: from NAM12-MW2-obe.outbound.protection.outlook.com (104.47.66.48) by edgegateway.intel.com (134.134.137.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.32; Wed, 20 Sep 2023 18:49:20 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=j2lMf+RO2hmnHO+BX1hxkmC0zEJY+HEZMp1ZDkHQMd1fySEq7fj2KPa2WBo37jb+JeEnTaRvDXVkBsHwbRHg3A8rL7MrFOpyd9h8ILOC49pMfZYFkh/swdikMrJAvsdpKoyMTpmPrcIfpGEWuZh+QiaP0CLwl3zfp7Nd8ekPy0/lBoTGj17KwQHghyyODi9Fx5ygXMzH0fYvjhjR1FWJ/h6rXMwiBGdzWOp0H/L5/MgCw/hbFBCVTJWOq5LHoznsz2GId7gII4Wo/4d+glkYUxkmKCL5oZogSAhP0d7zEjIVVvJIQ/we8Gq08kiyp2dwBcJGpUZOaJQkSunTVsRH8A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=+3aC1OVXl10q8xdpDYGn6D2IOakpCQbxwk421apnZV0=; b=NXbrtwktsjRY3IZ56Pi4e9LF9RQQAgLBK3Bh6lPFdgBE5Az/YFAxAa9x8neSdq6HmeYhbqVn8+mRzxn4IeDAwYopzqiTfVZB3l7REkkLQce0rKWVuQv0LgCK0CYqfOZg8jYPP+++L/Qn3hRIb7BxRPV2lm1LYQpt58JkSRz7GSEZmFQByQ8lIQ9mAO9qGmEE8IMC9NkCvAi0SqBKowzhrRcL+gfSBAJx2d8Q/KVi+TaGYWrou2zUddamPmfLH0/zoN2EUP27mrRgqwHnNsBAiV5j6uCW7iOA8YdrIucmdCjurtYReMBJqHiY91pY58qFjaQajtHgGVtEzUDtk1ACnQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Received: from DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) by IA0PR11MB7840.namprd11.prod.outlook.com (2603:10b6:208:403::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6792.28; Thu, 21 Sep 2023 01:49:15 +0000 Received: from DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::5e79:2d52:51e:f602]) by DS7PR11MB5966.namprd11.prod.outlook.com ([fe80::5e79:2d52:51e:f602%6]) with mapi id 15.20.6813.017; Thu, 21 Sep 2023 01:49:15 +0000 Date: Thu, 21 Sep 2023 09:21:09 +0800 From: Yan Zhao To: Sean Christopherson CC: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , "Matthew Wilcox (Oracle)" , Andrew Morton , Paul Moore , James Morris , "Serge E. Hallyn" , , , , , , , , , , , , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , Yu Zhang , Isaku Yamahata , Xu Yilun , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , "Liam Merwick" , Isaku Yamahata , "Kirill A . Shutemov" Subject: Re: [RFC PATCH v12 11/33] KVM: Introduce per-page memory attributes Message-ID: Reply-To: Yan Zhao References: <20230914015531.1419405-1-seanjc@google.com> <20230914015531.1419405-12-seanjc@google.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: SG2PR03CA0129.apcprd03.prod.outlook.com (2603:1096:4:91::33) To DS7PR11MB5966.namprd11.prod.outlook.com (2603:10b6:8:71::6) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR11MB5966:EE_|IA0PR11MB7840:EE_ X-MS-Office365-Filtering-Correlation-Id: 886be40f-a1ae-429f-606b-08dbba44f64e X-LD-Processed: 46c98d88-e344-4ed4-8496-4ed7712e255d,ExtAddr X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR11MB5966.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(346002)(366004)(396003)(136003)(39860400002)(376002)(451199024)(1800799009)(186009)(83380400001)(41300700001)(6666004)(3450700001)(8676002)(4326008)(8936002)(6506007)(6486002)(5660300002)(26005)(86362001)(6512007)(82960400001)(7406005)(38100700002)(478600001)(7416002)(2906002)(66946007)(316002)(6916009)(66476007)(66556008)(54906003);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?A1TxF1ewPD0395Uonf+hysQwW8vvr6rM+BME/jcPfIxl2NVZOrIUu21OFpbh?= =?us-ascii?Q?wsDI85nrxHlqDZHS+7VE9ITm9EbgCurIo8OS1qEnRUJ9YDxvzVnkdJz5VHyv?= =?us-ascii?Q?JkJzllwTofUgbSabqMHjjI4XvIPYYi3+vjgIluSM9LIS0pWg6IV9UuTXfxZC?= =?us-ascii?Q?OKf4pGYAw4fUljbUxhDaShwIUP1RPfq87l35e73YE89lO97vom6xlamX1H5y?= =?us-ascii?Q?nHf8F/nkB7kZrwytAtN2l/ju7/pNgw9yhFA8VCF0Hez92GNmJCfjRH2C9rLS?= =?us-ascii?Q?lVUcY6LFdQ74u+Z+42Y7QORcxv6aSALlwTmhJudJgrFq6xO84UmorrhrJONr?= =?us-ascii?Q?lPsnF8yQhT9XgFh1KIsvNKYLCJzBHCNOl4gNFGwnh0Hrmew4476ZHdMDAnuI?= =?us-ascii?Q?Yc51LX7wdtptO/hmH9cG9ZrGDuE5cl+DL5dVWNb/sI/2w3XKgO5O+UT0gaPt?= =?us-ascii?Q?BBdyaKJxDSpd9UdxTSnBVB8fUaVEoj00rtj1ynUlEw/i4cht8nPLBG0BheE3?= =?us-ascii?Q?FAlEvZp6VjaWluDVgza7glPEw9xDalD27Njd1TRcy8OAxTrnaZpby6sJOPOS?= =?us-ascii?Q?KoQyBZW+zggz+1sH7EOLUv7lsME/YoPAYnEXyUKczfpf2/1FSWBZSTfvRdoV?= =?us-ascii?Q?GaGxmmkY/ehqmLjhzebFHhls3H0nQgy7+/9Vh7rmdPq1O4VtWw2dHW0BelQ1?= =?us-ascii?Q?UazMQmR7gxVayimkdNWDvUS8vDK2gLZbvisq5pnXqsn2SSjHmlOy5mT+O5gO?= =?us-ascii?Q?RzCXP5OwcG5k7WN0fEg9ZW77OzJvbwnYvmRhv4+xLAnmyyNdAZXUDeGHj675?= =?us-ascii?Q?yM8tJkDRDL3Y6obxdTYUzr8FJ1j4vQoorVExqjPcccMGepG39Ron/uRILtni?= =?us-ascii?Q?xHUv9iILaNtMYB+OPgeEdkyduuTqofQV4Iv2LEKsTVbUQ5CUHnL3P7u5oE1k?= =?us-ascii?Q?Q+G473hKNGK3DuiaHi9Ipaj44S6wT7jKL766T7HAtxXhhvjuTKeLxmnjtbCQ?= =?us-ascii?Q?AeXzxAuZZL2s96t3Bhmj0e/695Zcb5mQyTjqhKFXDFYN8t9LqhudqGVdlOVj?= =?us-ascii?Q?ijLLlpnBF+X9/LHN4tMrREewDJuc9y/1AOO4UqOmp7YSTtcvcAgoeCn1365I?= =?us-ascii?Q?jyX9bkQHa4UVQy06VUI8NcXCKT/yQyQQnpw+0teD/+16+NwHbWSgO1IzVxrE?= =?us-ascii?Q?Sw2qrBnX8yKSne7TKt9Jt2RrE6BsLxgS6tGH6KBcMj82AW+7vibSaVkLN4F3?= =?us-ascii?Q?dmdt+x5iruTwIPE4OkOfyYH8tfY329xZ7pA6AeEggE6mtyw0rWMSEgWg0z0Y?= =?us-ascii?Q?FUzBbcXDPdUAkgXRxY26olK2Wf5e0Mg+0XM+L1vC94pYzP/nhevkR0V/2dRD?= =?us-ascii?Q?lx7o8s+umk25xuOmD0eAOhXn5bL1N7Z83lkAYZM4ofm4Zmp1LBMGj33eqN7j?= =?us-ascii?Q?LaDxIHlnRHWwdbyJbC5r7tQj3BideY/VAgzinFHQWDyy4I7D3TQ22Wc5E4Gq?= =?us-ascii?Q?xPWmPGC7cmqGTdp18y+lOzgSDPTSpbnYBB5IpYAQcsEEw3tpKxnLwctaa3lU?= =?us-ascii?Q?+msaURG+keUbpCdFDTwzOq4Q4z7blAK3gFQ15d1F?= X-MS-Exchange-CrossTenant-Network-Message-Id: 886be40f-a1ae-429f-606b-08dbba44f64e X-MS-Exchange-CrossTenant-AuthSource: DS7PR11MB5966.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Sep 2023 01:49:15.7430 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: JaDD69pDRW021RZZEY4PJ8iJCzQstnBmgg+iOI1fouHssJkHBeheMrtvgVCOrPg7sykZoq8JmuHYJIMhLVJODg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR11MB7840 X-OriginatorOrg: intel.com X-Rspam-User: X-Stat-Signature: 95jydfthp1apbddc4zk7d8b6i3mcnjj5 X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: C6443180009 X-HE-Tag: 1695260965-856047 X-HE-Meta: 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 Vr3ciNZK zZX3n4eDKBQNeqNVeXRUmHMCNmV1t4IwdesTiCFLOpUh9ffWsPW+sKWgFK6B0WgLenLuPNEY4PUTWFH1pYberBOkgZ3uT/+ikubZxjLxY78Qnq3Yo+jY3DhhqeWAwR41oISoACkxBXwLX7EfmHiXR0KTPPIkEKrG9qKIZrr9E4mTaeIuaNFUocsRXbvnKCRU4XSPnSBB9I3WcAL5Hl6bIgJlA8D7JfDRRVnILnPkPWqIRBrICMMt/Mpbsrl6911O91T8F5/+ulZSd+mcb06iLlKzO0rA9zCrigTyXqngkVQluRsyxpkdx4qdCd1qMnEpPh7u0A4XWpoAd6upD/u+xvwtxX4wHtBu8FKIhsiWiXRYKvEFfbF4VNZkUHPjSEONsA3syypsXgbZw6nn75HD9G7jb0gSBmxMrkuGy8kibXU4TilXKbb5mmtDFslAH4ukpxosAnyo9ZP2+O0zg+aKe/CNkyeNQY3RFy/sn 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: On Wed, Sep 20, 2023 at 02:00:22PM -0700, Sean Christopherson wrote: > On Fri, Sep 15, 2023, Yan Zhao wrote: > > On Wed, Sep 13, 2023 at 06:55:09PM -0700, Sean Christopherson wrote: > > > From: Chao Peng > > > > > > In confidential computing usages, whether a page is private or shared is > > > necessary information for KVM to perform operations like page fault > > > handling, page zapping etc. There are other potential use cases for > > > per-page memory attributes, e.g. to make memory read-only (or no-exec, > > > or exec-only, etc.) without having to modify memslots. > > > > > ... > > >> +bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end, > > > + unsigned long attrs) > > > +{ > > > + XA_STATE(xas, &kvm->mem_attr_array, start); > > > + unsigned long index; > > > + bool has_attrs; > > > + void *entry; > > > + > > > + rcu_read_lock(); > > > + > > > + if (!attrs) { > > > + has_attrs = !xas_find(&xas, end); > > > + goto out; > > > + } > > > + > > > + has_attrs = true; > > > + for (index = start; index < end; index++) { > > > + do { > > > + entry = xas_next(&xas); > > > + } while (xas_retry(&xas, entry)); > > > + > > > + if (xas.xa_index != index || xa_to_value(entry) != attrs) { > > Should "xa_to_value(entry) != attrs" be "!(xa_to_value(entry) & attrs)" ? > > No, the exact comparsion is deliberate. The intent of the API is to determine > if the entire range already has the desired attributes, not if there is overlap > between the two. > > E.g. if/when RWX attributes are supported, the exact comparison is needed to > handle a RW => R conversion. > > > > + has_attrs = false; > > > + break; > > > + } > > > + } > > > + > > > +out: > > > + rcu_read_unlock(); > > > + return has_attrs; > > > +} > > > + > > ... > > > +/* Set @attributes for the gfn range [@start, @end). */ > > > +static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end, > > > + unsigned long attributes) > > > +{ > > > + struct kvm_mmu_notifier_range pre_set_range = { > > > + .start = start, > > > + .end = end, > > > + .handler = kvm_arch_pre_set_memory_attributes, > > > + .on_lock = kvm_mmu_invalidate_begin, > > > + .flush_on_ret = true, > > > + .may_block = true, > > > + }; > > > + struct kvm_mmu_notifier_range post_set_range = { > > > + .start = start, > > > + .end = end, > > > + .arg.attributes = attributes, > > > + .handler = kvm_arch_post_set_memory_attributes, > > > + .on_lock = kvm_mmu_invalidate_end, > > > + .may_block = true, > > > + }; > > > + unsigned long i; > > > + void *entry; > > > + int r = 0; > > > + > > > + entry = attributes ? xa_mk_value(attributes) : NULL; > > Also here, do we need to get existing attributes of a GFN first ? > > No? @entry is the new value that will be set for all entries. This line doesn't > touch the xarray in any way. Maybe I'm just not understanding your question. Hmm, I thought this interface was to allow users to add/remove an attribute to a GFN rather than overwrite all attributes of a GFN. Now I think I misunderstood the intention. But I wonder if there is a way for users to just add one attribute, as I don't find ioctl like KVM_GET_MEMORY_ATTRIBUTES for users to get current attributes and then to add/remove one based on that. e.g. maybe in future, KVM wants to add one attribute in kernel without being told by userspace ?