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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9394BC433E2 for ; Wed, 16 Sep 2020 22:13:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D10820732 for ; Wed, 16 Sep 2020 22:13:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=microsoft.com header.i=@microsoft.com header.b="jf/puGxz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbgIPWNQ (ORCPT ); Wed, 16 Sep 2020 18:13:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726362AbgIPWM7 (ORCPT ); Wed, 16 Sep 2020 18:12:59 -0400 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on20716.outbound.protection.outlook.com [IPv6:2a01:111:f400:7e8a::716]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC00AC061225; Wed, 16 Sep 2020 14:35:04 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=M4BRRiinITmlfbQyIdNfvCDyEdDG/XNWYMPMqb7VbcU/AlxH2TvyypJrrVgeBrdAq4nvntxpoGm5buxLiznSb9euUPUbjg8k7ZZKfBIom+CRAnKvBKzyOCV064ZZAz08gZt4TVl+7IoBaaGaWlNH3pMn0untLZdZ+FnQrJD8yoUXfwemUtKZSnPt8BCbQnS/Ko0qz1gwPHDC0+dAmeEsUYR2lv0CdT9HVUzzJ0FlvS65swGe5vpStNSHnJtECeBdYLVswzB+5Ao504Y9KZUPke5pKr1RZScX0fJpgo4ijshpZOaqz3gTjuu2mm2AoHNPFvjbLvqMv4wHrN+YrsX0og== 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-SenderADCheck; bh=bHTW9WJ2D2UKkNPTvRPzDcy+ewHUPYevi3aGDo4ukrs=; b=Zldvm1eOkCyURa1tzLgzOlVDKvjtINf2/WOyjlsIKPNVCTUGFzZDBb0nClvG83CkzkVww3sphddj5K9lnsyEI02KO3TDXQxK9vJvE9W8TEyZ5P6aSwYRdNSEtm9eFHv6PqD9w9LwnJcR/K8LwOU/+M42FnDeMJnTarGEqmTD39S7Ionoe2bvdg3xAovM/Ya1xNCvE+gvID7ea9Ft2kSbuwa0GoUc/4s3Cc2ZdsyQjnpV9VZWdlUnIxhT8FInEo8I3X4mPYPJqTlBOJ2nspecVXtKaC3LcejpEqhSg1Cmjehns7CVSqb8f1JQrjlew8//R7if0bt3QNjjo+wY9+VIzw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=microsoft.com; dmarc=pass action=none header.from=microsoft.com; dkim=pass header.d=microsoft.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=bHTW9WJ2D2UKkNPTvRPzDcy+ewHUPYevi3aGDo4ukrs=; b=jf/puGxzDzX7MpWQZDm+wHcjivYX47Vr73cjUSPFruxX90o50LrCPQ+H4y08vFjQs0R/3ClGMk9Hn2JVcrWE7QwKda6lyHNj88oKY6jNgsxitCU/k7jBrmU5Q37JXYdsBMerOmJh3YPZtBdCC4WNpGO5TFeVSTZpUAfjXi0BpHk= Received: from SN4PR2101MB0880.namprd21.prod.outlook.com (2603:10b6:803:51::33) by SN6PR2101MB1854.namprd21.prod.outlook.com (2603:10b6:805:9::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3370.1; Wed, 16 Sep 2020 21:34:58 +0000 Received: from SN4PR2101MB0880.namprd21.prod.outlook.com ([fe80::b12a:e7a7:640e:8953]) by SN4PR2101MB0880.namprd21.prod.outlook.com ([fe80::b12a:e7a7:640e:8953%9]) with mapi id 15.20.3412.003; Wed, 16 Sep 2020 21:34:58 +0000 From: Sunil Muthuswamy To: Wei Liu , vkuznets CC: Linux on Hyper-V List , "virtualization@lists.linux-foundation.org" , Linux Kernel List , Michael Kelley , Vineeth Pillai , Nuno Das Neves , Lillian Grassin-Drake , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , "H. Peter Anvin" Subject: RE: [EXTERNAL] Re: [PATCH RFC v1 08/18] x86/hyperv: handling hypercall page setup for root Thread-Topic: [EXTERNAL] Re: [PATCH RFC v1 08/18] x86/hyperv: handling hypercall page setup for root Thread-Index: AQHWi0uJDiA8iBMLkEafMqtOkreLY6lpgb0AgAJJU9A= Date: Wed, 16 Sep 2020 21:34:58 +0000 Message-ID: References: <20200914112802.80611-1-wei.liu@kernel.org> <20200914112802.80611-9-wei.liu@kernel.org> <87v9gfjpoi.fsf@vitty.brq.redhat.com> <20200915103710.cqmdvzh5lys4wsqo@liuwe-devbox-debian-v2> In-Reply-To: <20200915103710.cqmdvzh5lys4wsqo@liuwe-devbox-debian-v2> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; dmarc=none action=none header.from=microsoft.com; x-originating-ip: [2601:602:9400:570:6d60:30f5:6f33:54d9] x-ms-publictraffictype: Email x-ms-office365-filtering-ht: Tenant x-ms-office365-filtering-correlation-id: 93eb277c-c9a3-4700-e4de-08d85a885c8e x-ms-traffictypediagnostic: SN6PR2101MB1854: x-ms-exchange-transport-forked: True x-ld-processed: 72f988bf-86f1-41af-91ab-2d7cd011db47,ExtAddr x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:9508; x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: /3OeSaKuZZh/9T7vDlzFEFJ5Ba4ftJyD4rdTihrZ/YdUVKHwK332cI/K4xtss04pElJ/SaGW/OlyA3bTI+0ABGkYo2uibliGd+mXMi6ckCJobAyRj47mO7LRFgg8qGltz+LP0m25clmj68wAqIGp4Ga1ud8ZIVKlxiEDH/3StfApahySGle5P6WOPcmpokg4KpEF5HF+AnXfFvUNztSriorj2d7UXbPu9BdZAu0o0UuGtoiecq3GQctWB7pdCVfW14UhqOb0iqDGYwGk4I3aYITopKuPMlfnS97dSXApQp3KRIjN7oTfKjrMG2w1B0UTxWJM08EVYDiJTDhev7R2jkb8psZ4x2e5FcKLxMw/bDexh6+Hods5HDv8o0zwJ8dG x-forefront-antispam-report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:SN4PR2101MB0880.namprd21.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(39860400002)(396003)(376002)(136003)(366004)(346002)(86362001)(7696005)(5660300002)(4326008)(8936002)(82960400001)(2906002)(82950400001)(8990500004)(55016002)(54906003)(110136005)(7416002)(6506007)(76116006)(33656002)(9686003)(316002)(64756008)(8676002)(66556008)(478600001)(66476007)(10290500003)(71200400001)(4744005)(66446008)(186003)(52536014)(66946007);DIR:OUT;SFP:1102; x-ms-exchange-antispam-messagedata: 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: SN4PR2101MB0880.namprd21.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 93eb277c-c9a3-4700-e4de-08d85a885c8e X-MS-Exchange-CrossTenant-originalarrivaltime: 16 Sep 2020 21:34:58.6016 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: EHj12QD3KuuoOmb9RGjokM24dSTx+XM9MRKV7qUQYMmYixe6Nc4TNXCEVhbdXiy2Q0b1Zy05nA7UTY7FfI3qVBvsDxZt8ZsU354aKtKd0Tk= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR2101MB1854 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >=20 > On Tue, Sep 15, 2020 at 12:32:29PM +0200, Vitaly Kuznetsov wrote: > > Wei Liu writes: > > > > > When Linux is running as the root partition, the hypercall page will > > > have already been setup by Hyper-V. Copy the content over to the > > > allocated page. > > > > And we can't setup a new hypercall page by writing something different > > to HV_X64_MSR_HYPERCALL, right? > > >=20 > My understanding is that we can't, but Sunil can maybe correct me. That is correct. For root partition, the hypervisor has already allocated t= he hypercall page. The root is required to query the page, map it in its addre= ss space and wrmsr to enable it. It cannot change the location of the page. Fo= r guest, it can allocate and assign the hypercall page. This is covered a bit= in the hypervisor TLFS (section 3.13 in TLFS v6), for the guest side. The root sid= e is=20 not covered there, yet. =20 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 X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07647C433E2 for ; Wed, 16 Sep 2020 22:54:14 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 75E902080C for ; Wed, 16 Sep 2020 22:54:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=microsoft.com header.i=@microsoft.com header.b="jf/puGxz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75E902080C Authentication-Results: mail.kernel.org; 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Wed, 16 Sep 2020 21:34:58 +0000 Received: from SN4PR2101MB0880.namprd21.prod.outlook.com ([fe80::b12a:e7a7:640e:8953]) by SN4PR2101MB0880.namprd21.prod.outlook.com ([fe80::b12a:e7a7:640e:8953%9]) with mapi id 15.20.3412.003; Wed, 16 Sep 2020 21:34:58 +0000 To: Wei Liu , vkuznets Subject: RE: [EXTERNAL] Re: [PATCH RFC v1 08/18] x86/hyperv: handling hypercall page setup for root Thread-Topic: [EXTERNAL] Re: [PATCH RFC v1 08/18] x86/hyperv: handling hypercall page setup for root Thread-Index: AQHWi0uJDiA8iBMLkEafMqtOkreLY6lpgb0AgAJJU9A= Date: Wed, 16 Sep 2020 21:34:58 +0000 Message-ID: References: <20200914112802.80611-1-wei.liu@kernel.org> <20200914112802.80611-9-wei.liu@kernel.org> <87v9gfjpoi.fsf@vitty.brq.redhat.com> <20200915103710.cqmdvzh5lys4wsqo@liuwe-devbox-debian-v2> In-Reply-To: <20200915103710.cqmdvzh5lys4wsqo@liuwe-devbox-debian-v2> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: kernel.org; dkim=none (message not signed) header.d=none;kernel.org; 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Peter Anvin" , Thomas Gleixner , Nuno Das Neves , Vineeth Pillai , Haiyang Zhang X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Sunil Muthuswamy via Virtualization Reply-To: Sunil Muthuswamy Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" > > On Tue, Sep 15, 2020 at 12:32:29PM +0200, Vitaly Kuznetsov wrote: > > Wei Liu writes: > > > > > When Linux is running as the root partition, the hypercall page will > > > have already been setup by Hyper-V. Copy the content over to the > > > allocated page. > > > > And we can't setup a new hypercall page by writing something different > > to HV_X64_MSR_HYPERCALL, right? > > > > My understanding is that we can't, but Sunil can maybe correct me. That is correct. For root partition, the hypervisor has already allocated the hypercall page. The root is required to query the page, map it in its address space and wrmsr to enable it. It cannot change the location of the page. For guest, it can allocate and assign the hypercall page. This is covered a bit in the hypervisor TLFS (section 3.13 in TLFS v6), for the guest side. The root side is not covered there, yet. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization