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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 16C61C433FE for ; Fri, 4 Nov 2022 16:02:33 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.437743.692193 (Exim 4.92) (envelope-from ) id 1oqz96-000408-8O; Fri, 04 Nov 2022 16:02:16 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 437743.692193; Fri, 04 Nov 2022 16:02:16 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oqz96-000401-4M; Fri, 04 Nov 2022 16:02:16 +0000 Received: by outflank-mailman (input) for mailman id 437743; Fri, 04 Nov 2022 16:02:15 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1oqz95-0003zv-Nt for xen-devel@lists.xenproject.org; Fri, 04 Nov 2022 16:02:15 +0000 Received: from esa1.hc3370-68.iphmx.com (esa1.hc3370-68.iphmx.com [216.71.145.142]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 0ac31687-5c5a-11ed-8fd1-01056ac49cbb; Fri, 04 Nov 2022 17:02:13 +0100 (CET) Received: from mail-bn1nam07lp2045.outbound.protection.outlook.com (HELO NAM02-BN1-obe.outbound.protection.outlook.com) ([104.47.51.45]) by ob1.hc3370-68.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 04 Nov 2022 12:01:53 -0400 Received: from SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) by DM6PR03MB5193.namprd03.prod.outlook.com (2603:10b6:5:241::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5791.22; Fri, 4 Nov 2022 16:01:49 +0000 Received: from SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::d197:992c:4dca:3c4c]) by SJ0PR03MB6360.namprd03.prod.outlook.com ([fe80::d197:992c:4dca:3c4c%6]) with mapi id 15.20.5791.022; Fri, 4 Nov 2022 16:01:49 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 0ac31687-5c5a-11ed-8fd1-01056ac49cbb DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1667577733; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=VkbPIL7eqP3CS0NPZl9NVAct9MCdv4M0mLZsnmutxS4=; b=UnjbaN0xhid1+aMmlbeD8ohmBytCxzG7iy6rJVj1VdujAFl9RVMLJ2n+ nGM17jfUvGwB6CUdBnUS51skxDKy0iWHG5Ne19Kg0s5DWlXcddkOIydyJ GVH7C9YkxG8iyJ1tAB1Bv6Z48qi2V9wzlA2x5Y7VaKm7doL3ytlZ/ROF/ E=; X-IronPort-RemoteIP: 104.47.51.45 X-IronPort-MID: 84615033 X-IronPort-Reputation: None X-IronPort-Listener: OutboundMail X-IronPort-SenderGroup: RELAY_O365 X-IronPort-MailFlowPolicy: $RELAYED IronPort-Data: A9a23:9AUErKm+gBcIEZYoAX/FKdvo5gx9J0RdPkR7XQ2eYbSJt1+Wr1Gzt xJKXmmGP/3bMWamL4tya4uxoUIG7ZaByNRiGgU9qiFgFiMWpZLJC+rCIxarNUt+DCFhoGFPt JxCN4aafKjYaleG+39B55C49SEUOZmgH+a6U6icf3grHmeIcQ954Tp7gek1n4V0ttawBgKJq LvartbWfVSowFaYCEpNg064gE4p7aqaVA8w5ARkP6kS5AOGzRH5MbpETU2PByqgKmVrNrbSq 9brlNmR4m7f9hExPdKp+p6TnpoiG+O60aCm0xK6aoD66vRwjnVaPpUTbZLwXXx/mTSR9+2d/ f0W3XCGpaXFCYWX8AgVe0Ew/yiTpsSq8pefSZS0mZT7I0Er7xIAahihZa07FdRwxwp5PY1B3 fElOisKSy+nu9i/2LilZtVqoNYnK/C+aevzulk4pd3YJdAPZMiZBo/svJpf1jp2gd1SF/HDY cZfcSBocBnLfxxIPBEQFY46m+CrwHL4dlW0qnrM/fZxvzeVkVU3jOWF3Nn9I7RmQe1PmUmVv CTe9nnRCRAGLt2PjzGC9xpAg8efwX2iBdpJT9VU8NZ2oR7N2VwDSyRPFkmcuOnnqEWPdfN2f hl8Fi0G6PJaGFaQZsn0Uxy9r3iFvTYTXtNRF6sx7wTl4rrZ5UOVC3YJShZFacc6r4kmSDoyz FiLktj1Qzt1v9W9aX+b7KbSkjq0NgAcN2pEbigBJSMa5/HzrYd1iQjAJv5hGqOoitz+GRnr3 iuH6iM5gt07j9MNkaOy/lnFgjeljpnPUgMxoA7QWwqN7Q5nZYjje42h73Da6+pNKMCSSVzpg ZQfs82X7eRLB5fUkiWIGLoJBOvxu6vDNyDAi1lyGZVn7y6q53OoYYFX5nd5OVttNcEHPzTuZ Sc/pD9s2XOaB1PyBYcfXm57I517pUQ8PbwJjszpU+c= IronPort-HdrOrdr: A9a23:aqN4F6MTA3Ov38BcT1P155DYdb4zR+YMi2TDiHoddfUFSKalfp 6V98jztSWatN/eYgBEpTmlAtj5fZq6z+8P3WBxB8baYOCCggeVxe5ZjbcKrweQeBEWs9Qtr5 uIEJIOd+EYb2IK6voSiTPQe7hA/DDEytHPuQ639QYQcegAUdAF0+4WMHf4LqUgLzM2eKbRWa Dsr/au4FGbCAcqR/X+IkNAc/nIptXNmp6jSRkaByQ/4A3LqT+z8rb1HzWRwx9bClp0sPwf2F mAtza8yrSosvm9xBOZ/2jP765OkN+k7tdYHsSDhuUcNz2poAe1Y4ZKXaGEoVkO0amSwWdvtO OJjwYrPsx15X+UVmapoSH10w2l6zoq42+K8y7tvVLT5ejCAB4qActIgoxUNjHD7VA7gd162K VXm0qEqpt+F3r77WvAzumNcysvulu/oHIkn+JWpWdYS5EiZLhYqpFa1F9JEa0HADnx5OkcYa VT5fnnlbdrmG6hHjDkVjEF+q3uYp1zJGbKfqE6gL3a79AM90oJjXfxx6Qk7wI9HdwGOtx5Dt //Q9RVfYF1P7ErhJ1GdZY8qOuMexvwqEH3QRSvCGWiMp07EFTwjLOyyIkJxYiRCe41Jd0J6d 78bG8= X-IronPort-AV: E=Sophos;i="5.96,137,1665460800"; d="scan'208";a="84615033" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=NqqPRBp2zxx4MQwVEbh/g4Qq7Vaa1vQOS8XZjCvHPbTWl5xZT0Dbzq+10aMpM+9FdMaT90+ERbzcG5I5OT79q+1R/1ma0+kBDj3bXJ3H4PDQ5RGJHnQ/JdQMGv9NlySWexzzlLO9z96QwOjjDgSo6ZOivAjaTSiswpYe8vGG+lvOx6U0aDeWrapAUTLNy8ch7rd482t/5FkPugBHoxlG6EL7KgK6XG8Tl1861jiAqXBLBgxyf+GO93dAFva+XOapi0ALRUhICXjhedr+pq+5ytcAZa66Sw9x5RcjEO6biEP+WUEmMWrM2uoWVLfRQCEykbmFG6qQpjllJh/zT4H4Sw== 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=DdADsRAL26iqXpbjPknC6YkRukOhKl7sqTPpsiKisxg=; b=CVu2WNdnLhTIUAWuQAYY48Hp5yHUo49KdW1T2exNaM4Xq+f/yTTyiHTsUlMPbEEga3PdtvEnJDzW+WW9Zt/p7LyyZYuvbBDR5Xl20SWoYy7lrwynw/LlwMW4XwFad61K3Gk6pJk1+vTeQdGKF7V4/5R63q/TAzGUR81lW1IFn87UcYqAlKt5CeW4PTkUTuFIFoTrR99pd0WTv36wMhiKHLJZrU59sofEKRXBOqgeoZ+ZvARKib39p9+UPBGVTUfOOB5VwZLGyujG+TLwuRwKTO6f0Z0uKOuXIeg3kVVBL+6JDUychw0Hu1W3XRwvG74Fp8oxKCsKSFq2yjVwh9zgQQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=citrix.onmicrosoft.com; s=selector2-citrix-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=DdADsRAL26iqXpbjPknC6YkRukOhKl7sqTPpsiKisxg=; b=LmDgRW48fco6hF97Umedjy1BGWq0aALigNPqA/bPCQKVpbaFo5a/v8rHeKo4ociiNJEix/cOBrdZIfnOc96DZIRvo7LmdN/q0XGtK6VSELTcGTdHFSvTAUMGjelzBBB3RqfpQqbYasjz6RwWt8NLweAOciw2dxjzEUFPsl8iV2c= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com; Date: Fri, 4 Nov 2022 17:01:41 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Paul Durrant Cc: xen-devel@lists.xenproject.org, Henry.Wang@arm.com, Wei Liu , Jan Beulich , Andrew Cooper , Jun Nakajima , Kevin Tian Subject: Re: [PATCH for-4.17 2/2] hvm/apic: repurpose the reporting of the APIC assist options Message-ID: References: <20221104142235.36556-1-roger.pau@citrix.com> <20221104142235.36556-3-roger.pau@citrix.com> <2a3c5141-516d-a5e4-392b-e7fe54f3781c@xen.org> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2a3c5141-516d-a5e4-392b-e7fe54f3781c@xen.org> X-ClientProxiedBy: LO4P265CA0231.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:315::17) To SJ0PR03MB6360.namprd03.prod.outlook.com (2603:10b6:a03:395::11) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SJ0PR03MB6360:EE_|DM6PR03MB5193:EE_ X-MS-Office365-Filtering-Correlation-Id: 76af45c9-0f4f-452c-f105-08dabe7de19a X-LD-Processed: 335836de-42ef-43a2-b145-348c2ee9ca5b,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:SJ0PR03MB6360.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230022)(7916004)(4636009)(346002)(376002)(39860400002)(396003)(366004)(136003)(451199015)(6506007)(316002)(9686003)(86362001)(8936002)(83380400001)(5660300002)(186003)(85182001)(2906002)(66556008)(66946007)(53546011)(66476007)(8676002)(41300700001)(6512007)(26005)(4326008)(33716001)(478600001)(6486002)(6666004)(38100700002)(6916009)(82960400001)(54906003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VzBnRk16dlN5Vm9mU3h4U3NieUttYkZpZlJ6QnJuM01HdndPQ0FDRzJLSkhy?= =?utf-8?B?NWtTNUY4eVhFZndwNVNoMzZBaHcwYm1nWFhHeW1BU1Y3S0hWNnlkbXdLYS92?= =?utf-8?B?dVBEV1YxdkdycGNEeTlBcVNLdjRGZGJ1aSszTDRiU0srNGN1SVFpQXUwdHRp?= =?utf-8?B?KzZPanQrYUFnZXlja3ZlK3J2MlR0K1ArYzg3RFc3L0szUkZVVDluT1dya2hx?= =?utf-8?B?L20rNm1JMTBOQlp5NHNxTEE3NXM5UEJhbWJnMTUzcEFTMzVjK3NCVzU1b0ZS?= =?utf-8?B?RFR0WTh3RWV0Lys3MEhuMGdEMGlrM1VvTEFlNWlvZ2tuUXlVSXdRbTliU2lH?= =?utf-8?B?c3FOTDlnbG5qZ0VOV0NlRjlCd0phdkZabWY4SC80L3R4V09NSlowR1JhdU4w?= =?utf-8?B?ejYwQlc5SDJDM3NDNXVPWEhDZ0xCa21vZlE2aGJKMWQ4WEVDOUlPZzJESk5p?= =?utf-8?B?SkY4Tk8rNFhOT3NLR05VYkRtY1VxeUZTZWt3N25uQWExZnRpL01VU3I4R3l3?= =?utf-8?B?QUhsR1VOTVdMYWZtVGpTc014c3J1WUVOdCt6eks5enVUbnJXN3NWamo5SEhG?= =?utf-8?B?WFBXenlvR2hyTWgzYkljWm5pTytPbXlLeUpJdHR2ZDdLS2ZBbUJKQ0RMNC9G?= =?utf-8?B?WkgvQlN6OU0rTG4vdG90MHJ5TjA2YWZwTWlnbkptVUpUYnFnU1padzdnVHls?= =?utf-8?B?cWw0dXAvTmFzS2J2b1FVNVF5TGQyd3FaTXhGZVpQUGsyOWl6RlU1OWd5K2lC?= =?utf-8?B?Q1c2OXVRcU5tRmozSVhicG1sODFQVlp5MHlNTTV2S2s2ZmhNQ0l0Vm1QbW5C?= =?utf-8?B?UFRScXJpRklBRWNEMHA2Z3J1b1hqMEFQQ2M1Wmx6aVdXQVUwVnFDMklEazVv?= =?utf-8?B?elNuWlFoV3ZEZTJsRm03dzJMYkJLSk9STW51WlV5Zm1SUTgzbjRWblFhblY4?= =?utf-8?B?V0paazhIaWxaaVVpaUpJNEpTWWVEZDd3bW1TQW5VejZiMFZJMSt3YWNUMFFY?= =?utf-8?B?SUh4QmNTUThRNjZjc1BsTVFqQml4WTNzVlNoNFRGaXhVNkN4ZHdLT05VYXNU?= =?utf-8?B?dXdSTVZNKytmS0wzQU53U1ZYcjRsWWhvRkJabDdWQ1BuY21EcG5PaEp2VjNa?= =?utf-8?B?ZTlRUXgyMVppWmZoQWtpSUExVXNSUG5oQjRZZ1ZPSVdMODNuQ3YyeTZESXpk?= =?utf-8?B?VWpBVlZnT0plWEJlSDFpRU1iZ0p5YVowYmRDTGRrbllnYlROZE1lZzFQNUtJ?= =?utf-8?B?bnpiem1UM0V2NnNoYS9jZHVVNWFwQVdFdmhkSlgvUzd6bWlybFpTTHVobUFL?= =?utf-8?B?MmdNYjFYZkJTY3lQRSswYWlWNFRLbUNVbUJkS2wxVXd4TFdIb1J1TkNHZHZh?= =?utf-8?B?bGxLM1Q3S1ZYdUZRTEpSRXRST2RCTlpENWpHOU9pS1B5S013R2xQLzlKTVIz?= =?utf-8?B?cDdKTlR4R0RDYlBYanNKbzhRZDFBVDVSTTB6NlVsWkFuZi8vWm16NjVBOGRp?= =?utf-8?B?RHlCWGl5andrSXE5b0RMOWoxRW93bU10UHNuK1FXdjBRZFhDdTJSbHlvR21X?= =?utf-8?B?Skt5WWxYTzRJZlBHRDY2V2xnUlpUT1l5ZmlNRkpUaWMzWWI3bmxIQWVPYXhu?= =?utf-8?B?U1NOTlNXQlY3dkVpaURGRkMxV3N2bUtDMzdLQTFieWc4SGhad1dQcTREbjk5?= =?utf-8?B?ZEVUdmVpNUxtTVV2ajQ5dFlBK2VkeGZXUWRETGtGTm1Hak5yY0t0MmRzMlRM?= =?utf-8?B?bDZId0hqRXNLQzFDQVpJYk8xc293bFFPdVVYdE4yTzQyaGFEbVA4NVNaSk1T?= =?utf-8?B?N0RDRGsxT1JUbk12QUUxSTQ0NVlzWjBNaE1BaGVHVWpxSWpLSzR3N1JyRW11?= =?utf-8?B?eTVHMnBSOTRoN09VbHc2WkhhZVlQcmNPN2o0R1ZhVWpHUmRaeFQzV3QrZUhH?= =?utf-8?B?R1B3akNNL0NFWXJWdUpTenc2eVBJM1hWWDNCY3pvZG1wVFZ2TWtGRVBYMUFW?= =?utf-8?B?RUtHOFZlbGJ0U2hwZjJuUStSMzN4Vy9YdDMrVSs3UktDYjNOcHZWbEdDeEpi?= =?utf-8?B?UVdxa1FsY3lYQS9jY0NacWh0WjJXQjFCTU1lc21NU0ZwSUVnMkZyR2RXWlFl?= =?utf-8?Q?j/n6X3JZYKlXPaijNbO2B7HDK?= X-OriginatorOrg: citrix.com X-MS-Exchange-CrossTenant-Network-Message-Id: 76af45c9-0f4f-452c-f105-08dabe7de19a X-MS-Exchange-CrossTenant-AuthSource: SJ0PR03MB6360.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 04 Nov 2022 16:01:49.4219 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: uATGNShFgOivSRXDxCUkaTgedvDlf8Fyt5O3p95FiU5N/sTEuF4z9xuce5Nc2l3icKc6PKGSTy48LQDAPGw10Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR03MB5193 On Fri, Nov 04, 2022 at 03:55:54PM +0000, Paul Durrant wrote: > On 04/11/2022 14:22, Roger Pau Monne wrote: > > The current reporting of the hardware assisted APIC options is done by > > checking "virtualize APIC accesses" which is not very helpful, as that > > feature doesn't avoid a vmexit, instead it does provide some help in > > order to detect APIC MMIO accesses in vmexit processing. > > > > Repurpose the current reporting of xAPIC assistance to instead report > > such feature as present when there's support for "TPR shadow" and > > "APIC register virtualization" because in that case some xAPIC MMIO > > register accesses are handled directly by the hardware, without > > requiring a vmexit. > > > > For symetry also change assisted x2APIC reporting to require > > "virtualize x2APIC mode" and "APIC register virtualization", dropping > > the option to also be reported when "virtual interrupt delivery" is > > available. Presence of the "virtual interrupt delivery" feature will > > be reported using a different option. > > > > Signed-off-by: Roger Pau Monné > > --- > > I find the logic in vmx_vlapic_msr_changed() hard to follow, but I > > don't want to rewrite the function logic at this point. > > --- > > xen/arch/x86/hvm/viridian/viridian.c | 2 +- > > xen/arch/x86/hvm/vmx/vmcs.c | 8 ++++---- > > xen/arch/x86/hvm/vmx/vmx.c | 25 ++++++++++++++++++------- > > xen/arch/x86/traps.c | 4 +--- > > 4 files changed, 24 insertions(+), 15 deletions(-) > > > > diff --git a/xen/arch/x86/hvm/viridian/viridian.c b/xen/arch/x86/hvm/viridian/viridian.c > > index c4fa0a8b32..bafd8e90de 100644 > > --- a/xen/arch/x86/hvm/viridian/viridian.c > > +++ b/xen/arch/x86/hvm/viridian/viridian.c > > @@ -201,7 +201,7 @@ void cpuid_viridian_leaves(const struct vcpu *v, uint32_t leaf, > > * Suggest x2APIC mode by default, unless xAPIC registers are hardware > > * virtualized and x2APIC ones aren't. > > */ > > - if ( !cpu_has_vmx_apic_reg_virt || cpu_has_vmx_virtualize_x2apic_mode ) > > + if ( !has_assisted_xapic(d) || has_assisted_x2apic(d) ) > > So, not sure why this is separated from patch 1 but stated this way it seems > counterintuitive. We only want to use the viridian MSRs if they are going to > be more efficient.. which I think is only in the case where we have neither > an x2apic not an assisted xapic (hence we would trap for MMIO). I've read the MS HTLFS and I guess I got confused, the section about this CPUID bit states: "Bit 3: Recommend using MSRs for accessing APIC registers EOI, ICR and TPR rather than their memory-mapped" So I've (wrongly) understood that MSRs for accessing APIC registers was meant to be a recommendation to use x2APIC mode in order to access those registers. Didn't realize Viridian had a way to expose certain APIC registers using MSRs when the APIC is in xAPIC mode. I withdraw patch 1 and adjust patch 2 accordingly then. Thanks, Roger.