Received: by 2002:ab2:3141:0:b0:1ed:23cc:44d1 with SMTP id i1csp1691508lqg; Mon, 4 Mar 2024 00:06:19 -0800 (PST) X-Forwarded-Encrypted: i=3; AJvYcCUSjHovWFWijy+Iaor4761qk2jOQ5Dw+8R3um3jr3cW2pp1CvhcY/3/5GtK89v9TCiArfTzCSolpvS0XOVVC4tVdY3Zd2/XQxgqQysxPw== X-Google-Smtp-Source: AGHT+IFYYFUkkYPSz5F8b4jCaQ1ZCJhWgU5k9SK7bNHYpngKDPcnbTzg9QVS3zCWSh7eh0LfPQbv X-Received: by 2002:a50:bacb:0:b0:567:1797:426f with SMTP id x69-20020a50bacb000000b005671797426fmr2855058ede.24.1709539579764; Mon, 04 Mar 2024 00:06:19 -0800 (PST) Return-Path: Received: from am.mirrors.kernel.org (am.mirrors.kernel.org. [2604:1380:4601:e00::3]) by mx.google.com with ESMTPS id s4-20020a056402036400b0055f27dea051si3712747edw.347.2024.03.04.00.06.19 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 04 Mar 2024 00:06:19 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-90164-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3; Authentication-Results: mx.google.com; dkim=pass header.i=@intel.com header.s=Intel header.b=DTisB+WN; arc=fail (signature failed); spf=pass (google.com: domain of linux-kernel+bounces-90164-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) smtp.mailfrom="linux-kernel+bounces-90164-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by am.mirrors.kernel.org (Postfix) with ESMTPS id 559311F22687 for ; Mon, 4 Mar 2024 08:06:19 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3B5C7171AE; Mon, 4 Mar 2024 08:06:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DTisB+WN" Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 2BD3B14A8C; Mon, 4 Mar 2024 08:06:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.7 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709539568; cv=fail; b=szFmch2SYfknf3aYMx3YBeQHAstQIWZ7iI3uS1aDZRm5D5vxqc5v6Ze+qvaRmWRd0Rb1gyRTrUZ16Ltpgdi5+2X5Yc9Y5JCMszuyknvg4+6+kaVnojq2Ag9DjT/Ex81mlLaopSiBZfxpCCv6UY2IKEvptjVBhDmDf8Gk0WZX8Z4= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709539568; c=relaxed/simple; bh=N6i/UrEc6iXyHkafR3IiG8tWh+W342jJ5U4oTzCRtoY=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=W8jL1eYXuoCzrKXE5Saq2HFHOMJj2trxWXpfbbYRyl2SadIrUIcOrd07JKsBulTw1dRZDhPq5snHfXR7h18loRABMGalA+tNMpe0foskIAbWQESVguAucSZr/hTKiRqBXeK75RKXwSuRbPcuxM4JpOhU8rheo7K1gB8qTkQFbXc= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DTisB+WN; arc=fail smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1709539566; x=1741075566; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=N6i/UrEc6iXyHkafR3IiG8tWh+W342jJ5U4oTzCRtoY=; b=DTisB+WNccPg7rrpSP/DfC0nupJetW4FtvrvFHbtbcypWap+7k1s7xZE 6koQijlu098p0uFU+x8gXyjLCluw0vvdq2+U+uAQZuAapivNSoncImUZl Wkg0D+bHxUDTFgmXr5v8qOZpEJ8Co34waJvVif5Y73LSnracUJ3/a8opJ D0u93RIBUh5g1GLw1n4wpI0DqnkPuG9vzYbE+I1feTQ7SIZi8jyFu/Jmg AMOepoW+r3m8zZoe9UIB+28zkT5Y1/5ybamqsVrogJDAJK4u86F9BjIsM X9JpO7F/ayOT8VkeKzBO79wMGbRzM1MZs9FIuhMHOoEAiOzHnfBtG1AJo A==; X-IronPort-AV: E=McAfee;i="6600,9927,11002"; a="29440286" X-IronPort-AV: E=Sophos;i="6.06,203,1705392000"; d="scan'208";a="29440286" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2024 00:06:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,203,1705392000"; d="scan'208";a="46419635" Received: from orsmsx601.amr.corp.intel.com ([10.22.229.14]) by orviesa001.jf.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 04 Mar 2024 00:06:05 -0800 Received: from orsmsx610.amr.corp.intel.com (10.22.229.23) by ORSMSX601.amr.corp.intel.com (10.22.229.14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 4 Mar 2024 00:06:04 -0800 Received: from orsmsx610.amr.corp.intel.com (10.22.229.23) by ORSMSX610.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Mon, 4 Mar 2024 00:06:04 -0800 Received: from ORSEDG602.ED.cps.intel.com (10.7.248.7) by orsmsx610.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35 via Frontend Transport; Mon, 4 Mar 2024 00:06:04 -0800 Received: from NAM04-DM6-obe.outbound.protection.outlook.com (104.47.73.41) by edgegateway.intel.com (134.134.137.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 4 Mar 2024 00:06:03 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=i5V6IZkhb4+szVmAruCFQUacwQ9WL9LQEYOeftHeNW1xAMUI4ihncWsvAox/ea4J0ffOuIehb66WCreDMh4C/532T04Mhpyaf510gVeJXr5GLsOu7oWidHpGgSUf/THsr7eXN4X4061vok1Yt2CM/47L83HYErhcRhjFAwfSnJbH2XIN7uX/AOmKeSXz1Y7RPoqieW+oI7Moyb/DBvGLxdagydNbUN9A94yMvm5NBheduxoaBGPJOX2JioxcSxDVoSd4Erwdn+Evls9ba0H+NfzXInDDPsdvfHzRdADIT0TCC9hHZuSJiTgyHvS5uGWSOLYlPajrlzSrxUlFCM0OPg== 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=rcpNDrGbjxSmQGc94msUJz67J6WVOpJ0Hocin3fJZIQ=; b=U4dHC/cEDAsgGgFAp/9L1gyuhVMRSqu41in9GVlLrSv3t4jZdmzQxdVzRtk3umBZii9BCcWm9kZeuupsZLdECBziBN2JkioavDEeV7gZ63HQ84TczlaClgS+lAB7c827Qjaafcg0RDrFknwzrb4stxfSp7quIPyQPx5zQNo/evslCXN/N4jOISEsQ+OpnWu4j8NSqry99bFKCYQG3xorFlq179WhpCKMmkYSaFGpnOe1jCCc9FT2b750PRLB4fVAVA/iIH7MLb1lpl5tpTauVDCaWrNwM12KarQsF0jJgeKTx4FwN9cjd7HD/+vIcJtftbRKKENvz5jli6yuJ110Vg== 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 BN9PR11MB5276.namprd11.prod.outlook.com (2603:10b6:408:135::18) by CY8PR11MB7731.namprd11.prod.outlook.com (2603:10b6:930:75::21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7362.23; Mon, 4 Mar 2024 08:06:02 +0000 Received: from BN9PR11MB5276.namprd11.prod.outlook.com ([fe80::39d:5a9c:c9f5:c327]) by BN9PR11MB5276.namprd11.prod.outlook.com ([fe80::39d:5a9c:c9f5:c327%5]) with mapi id 15.20.7362.019; Mon, 4 Mar 2024 08:06:02 +0000 From: "Tian, Kevin" To: Alex Williamson CC: "david@redhat.com" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH] Revert "vfio/type1: Unpin zero pages" Thread-Topic: [PATCH] Revert "vfio/type1: Unpin zero pages" Thread-Index: AQHaa1+9vCqOMpJOeEum19hngVFPlrEnPr4Q Date: Mon, 4 Mar 2024 08:06:02 +0000 Message-ID: References: <20240229223544.257207-1-alex.williamson@redhat.com> In-Reply-To: <20240229223544.257207-1-alex.williamson@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; x-ms-publictraffictype: Email x-ms-traffictypediagnostic: BN9PR11MB5276:EE_|CY8PR11MB7731:EE_ x-ms-office365-filtering-correlation-id: 8955c062-c0f9-4f3a-52f7-08dc3c21ef00 x-ms-exchange-senderadcheck: 1 x-ms-exchange-antispam-relay: 0 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: +ZbaxQPWcteUShNZ7rzMbiEKzKfX/WJncUY2f4o5VsurCZJPbiTJuiETDRqSDXSoV1Y+G8yH7jRMXlDuNjH5J9ZdBqbp9hGRQz+f4anCHE3FF02je8W6xG7H1SRZSVb2Q8YXtQzsYtV4XgFLAEhxghUdIHoRwLt/bCtiOLEixevNAppdjXBbD3iCb/0j7OOrO//dgRdtpgkPatQCGEeXq12PndOVjEbfr3T2Vg/UKjR6FgUKIbKulo3zyioAMvqM9C3+yUMHos5QvcgVlJSGncgfyGyoIJPveWHnioZVuOWZ8G4lCkAiTilHgn1xgzs1zOyHJAHNeY6iOBFb1qEcEc00wDxwQmlTzXQM0u0MFEWkiVgFpq2Un8rkccsE86eOcoT6gNWWLwdr4fdT80tudhWcxdy0CgloLiEsVV2OPW++hNkEntiTT1kTCzIg5yL2r8UbNbbY96JRjEHZKMJEFCjycJ+h/tWH7a4G+gLTtmaXqQ8G5w0Ys/fH4FygC3C3ZjtNN7RbJ1HljfqvBxP17j/3nJlBzpEpRsJdyY/2qXl4c8ibTL+lMSREx8jMxXJzLuHbX/+aYcKApqCluasO4F9ZwtwcF2MTQikJOrGzUryFR1Kk4ta37+mZAAeHh2PAq/W2r8wjkqvwAp3ZF5v4kB14bj32zvqNLVa1ukFizJmoOPZzILHpMXMpGLCKQ42c/+nyHsh2bWATIcpB29sxBr3PnZ7M9chMITX+aNM0qio= x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BN9PR11MB5276.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(376005)(38070700009);DIR:OUT;SFP:1101; x-ms-exchange-antispam-messagedata-chunkcount: 1 x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?8nncwu3guiX2L6IF4mpBmtmasbPZ717fL5HhhHOX/MB28PhhnewO6WjnXC3M?= =?us-ascii?Q?M7Jjq98xuturbHFwbVtjksyCSqHfZoU4sndGmhbHCRY4IosAPVQMvABx8xOF?= =?us-ascii?Q?ljcXFrtY50CRNHt7SrcEayX328mfZllhYg2nlstnJgJMwfeMYpPEiAF8Zf0c?= =?us-ascii?Q?0XUV50vXBQ/wBJM6v4AYMS0BrSgwMHOZfabzYhp1g2zFJT8gxmFZ115ckMk5?= =?us-ascii?Q?WXE69qUu8QT93LPnORf8cDrF2AjP41r3941sr5LcJUalwm5lcGMwydAcVxks?= =?us-ascii?Q?3WaaTfRD9KMcab2HdDZCohPBP3Cnv2MwXVeDoNVZA5fsO/v4Fn6rZp3vV2Lw?= =?us-ascii?Q?4tIKk2sHbbHrV2AuWOSa0R1S7ZDIzHGXWusPt1gB1FilL4NhO2gj7tAMO5l4?= =?us-ascii?Q?g94kc/duKVthlj54RFEvxJEz79FYb/Jr0s/VbiyrTcyZhGu8Wduk+eh4Msdv?= =?us-ascii?Q?1uBmi3zs4zv3sYid9kxWV/dIorhyGgAJL6sXDcdtKILGJrWemdZ/m1FHXtbg?= =?us-ascii?Q?i7WVfaPpVh85k++Z3NfQLfzusBJkHWy2m3tf9thSBYQOUI85+68Z6DsGXP+l?= =?us-ascii?Q?tJT7u2mi1UMsh/Bnv8xMVrwJObLlf0ZHI3jHk6C9EyaTH9q88FlKLiHTQ8yW?= =?us-ascii?Q?OpNc6XaREjdeSzG+MkkQNFGBrGimjm+ZurCIf/XDdwf5MPs6KeU7aTLOW3RW?= =?us-ascii?Q?caMDQuRBstq9xwhDGuA1T2o9RMoRXUyqAgLOKj7Falr5VvHs4/Y0ON8UE9Zb?= =?us-ascii?Q?fN8NoCq9vImm9W5vTzYYkQSWnsLn/bX+qfg/fj6KtP9GyIM5ztQPzTUbKK08?= =?us-ascii?Q?oDnAXQzVHLhIfsVCQXKtZQzHGOzyfeCFdpvs63cecqkYV3UNeNACXpE3oMpu?= =?us-ascii?Q?I38UfxzXjzfoZ3SX1WPTusBzoWkszDs+CLB/Jz/fPuhJ56oazfoqht2DxVhU?= =?us-ascii?Q?ehHYUk6lsqU8/QRht+2Ri53+lNL/nNVS0Zz3+tl+9LcKCTqzP2E8rCzbzMM+?= =?us-ascii?Q?nQU/O3DiRxCoN/tVrbYdNSHo7NvYhumdFG+uPMR1/V0L+EuHEJVW2Bhpe5O6?= =?us-ascii?Q?foMJru1mf6AfxidH95HEP+S2vufQQawRJUX+JKuyipIminYtjNcwy4wapqJy?= =?us-ascii?Q?HkBCZazXrlrx07YLCl5zw1aFC+SjD2ssK5ZSAY2ORhNim8h6CZF9MUGXs3rv?= =?us-ascii?Q?Xdb5EuIZYgS9PbrDknuuZSiYI0VEP8Zo1dUFe6sfePg/8Qyo9nMEBpSBF/R2?= =?us-ascii?Q?lZJx2WrN/JYPusmrYntl14l9RonCAOgdKab+5vkKJJ0SFNhGQjtW4/nDBIjo?= =?us-ascii?Q?f2+FD8SysJ7009V6/4x3u5HE5c+q/+89wTer5lWkQu57fHhbIecm6UyavjuM?= =?us-ascii?Q?MG6R8hB1daZDpd5fXHsku0mZ7EAlwigwe03ahCJYZw0lMkDtTgFzGxxrO0Pr?= =?us-ascii?Q?cSDalp+VmdmvJKZynlmoFzyLTvAXdv74s8WRm8tBf0i402rRXrzXE4LNBf0j?= =?us-ascii?Q?dOqTS7wsYTmK2bGR4Qmalp5Fg70LU+4qj4Y5/jeTtY/I2EZ71tkxdjVnPNW6?= =?us-ascii?Q?X+bPEbJAn8A/OTiY/GSwsrtTeL81D3NjVEZgnnih?= Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: BN9PR11MB5276.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8955c062-c0f9-4f3a-52f7-08dc3c21ef00 X-MS-Exchange-CrossTenant-originalarrivaltime: 04 Mar 2024 08:06:02.0800 (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: Ugegw7+GR73yX4PiNswefYlGP4HocumPcqn6iXSsOErNOtyPMSFbXW5Bn0/LnptxuvyhmLB3j+Hn0B9sGheJzg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR11MB7731 X-OriginatorOrg: intel.com > From: Alex Williamson > Sent: Friday, March 1, 2024 6:36 AM >=20 > This reverts commit 873aefb376bbc0ed1dd2381ea1d6ec88106fdbd4. >=20 > This was a heinous workaround and it turns out it's been fixed in mm > twice since it was introduced. Most recently, commit c8070b787519 > ("mm: Don't pin ZERO_PAGE in pin_user_pages()") would have prevented > running up the zeropage refcount, but even before that commit > 84209e87c696 ("mm/gup: reliable R/O long-term pinning in COW mappings") > avoids the vfio use case from pinning the zeropage at all, instead > replacing it with exclusive anonymous pages. >=20 > Remove this now useless overhead. >=20 > Suggested-by: David Hildenbrand > Signed-off-by: Alex Williamson Reviewed-by: Kevin Tian