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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 95A0EC433E0 for ; Mon, 8 Mar 2021 11:38:18 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 242D46511F for ; Mon, 8 Mar 2021 11:38:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 242D46511F Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=citrix.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.94814.178569 (Exim 4.92) (envelope-from ) id 1lJEDA-0007mQ-Qc; Mon, 08 Mar 2021 11:38:08 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 94814.178569; Mon, 08 Mar 2021 11:38:08 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJEDA-0007mJ-Mu; Mon, 08 Mar 2021 11:38:08 +0000 Received: by outflank-mailman (input) for mailman id 94814; Mon, 08 Mar 2021 11:38:06 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJED8-0007m9-Ij for xen-devel@lists.xenproject.org; Mon, 08 Mar 2021 11:38:06 +0000 Received: from esa4.hc3370-68.iphmx.com (unknown [216.71.155.144]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id e7250106-8053-4e9d-a408-cf166b7d2a68; Mon, 08 Mar 2021 11:38:05 +0000 (UTC) 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: e7250106-8053-4e9d-a408-cf166b7d2a68 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1615203484; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=UiDoH4ubFhxvZZE1S32tNzBJmS7SiN93C0HiGa9EdBA=; b=g2k721o/TsAod2FkYPEVNRXrT4cNWptf1on7eO3vI/9aUiGR2BFoSHpK j1D5RDDbA1QMARm10dmDLZRZXa50XC6Fg2NkQKE61BtZxYyeeCkAudSto PPJaZVStl3DGLWBuhAN/Ex16aHvmMHGISh1bXwhOzPTcPfQ9m1YPv/Re2 4=; Authentication-Results: esa4.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com IronPort-SDR: ZawCvNDIHC6aUOfblvYyke+0VyMEb1leck/Oq3FZlNLSvXUoKTg4HtKxwkIQ2KPQeRkUmesemC SACSud5uGau3DgxAiOsZJVCBuHD/ErIgZiAZNwlxbKsdbA46N8uvrPKrYwkzXu2p+xolOwZiW5 hxUqjrZwsW8WvIPF0xUvaEwznWK9+R5CPvRIG32RAkDxCWpPawIG6VUjQLBxv9mcjf1FnExfkF wNpPzOZmygRRCSQucSmNd5vYljEmd6ZTdNXHPrxTpl0+X2aFTdTlqlVDyAaxzhXAMk5g0Nco2F OAE= X-SBRS: 5.2 X-MesageID: 40169225 X-Ironport-Server: esa4.hc3370-68.iphmx.com X-Remote-IP: 162.221.156.83 X-Policy: $RELAYED X-IronPort-AV: E=Sophos;i="5.81,232,1610427600"; d="scan'208";a="40169225" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=iNUtPuc4HUMihEjGW1/wAz/TjeVbNmIG7/ebQoytcjxKSypPWGdzmduby2CUON5llxcsHKjD8pLYcFWfxejlTPIKOMFb5n0XWYS4yNfZxQ7hPQUUJi4c1kXT0+6Z8NkM2K9veJfi9r7ws8pTTsYeT4nXtgLEib1G/jcBFuk6gkfW3ksP2EmcbgjHRYaiNE8W2jTaSP25VYsV4JmFvrjM6gdsYp2GU0I5TXkZeAjR1MZhSiH1C1QZKEZ4mk6JMI0zQS2qLeUqXdsOr0Dnc/pnVXIH2TYW3qB2RNj6esItsvWQeVXL2Jiohx71qsZYh4FOG5uKp1Swhv6GU3AyKFyBcA== 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=vqRbU6BlIqaSzOEclvGQ11l9rYi7gl+ROTirI7UOxfI=; b=OBy33utGN/6Z9u+Nu5kcpJfaJpc0kUGjVYkSJmN/ghuG5QqK+oSQQ1N+Z6rA/BFFSu+B/8bBJ7fQn7rXJd+Ui/9oFIxMA+3VvO3EenTvvlkupFWqFPpEO05/tRAH9v8PgzUXPcS8tHg1N//xKKTaAVDJKxHwgO8wCI2HuJ6UDkRHEBU9a/WCDSdvUq2hWxaF9I9pa1P9vL6izD3nh/qLI1jy+/TT0qKStxW0U+zvTWEZkYcRcIa0aMV+vPRc2eG5N9OOqcYupjDccuzkTss/h/tcfvEEsVRnBcSvdVH7AedmOfh5p81HK91JBPdFUUgCMsGTPyRjwdBxQbbIhecWQA== 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=vqRbU6BlIqaSzOEclvGQ11l9rYi7gl+ROTirI7UOxfI=; b=gH8LluUC97BaOpRSHzTDPa19trznwOElESy0Zp79JILz03ukYqAbGKy3MFz90NWuhhyoWZgLZcyXJIFiTnwQhHlOVvQ/LV89OVwzj2kaAmJB7vJwcm7GB1DGt/8TuKE9ePPMg3cpXpLiYhiufRXTQ/w2Ekrmz7rnfac78Sy++CU= Date: Mon, 8 Mar 2021 12:37:37 +0100 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich CC: "xen-devel@lists.xenproject.org" , "Andrew Cooper" , Wei Liu , Ian Jackson Subject: Re: [PATCH v2 2/2][4.15] x86/AMD: expose HWCR.TscFreqSel to guests Message-ID: References: Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: AM7PR04CA0022.eurprd04.prod.outlook.com (2603:10a6:20b:110::32) To DS7PR03MB5608.namprd03.prod.outlook.com (2603:10b6:5:2c9::18) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: fa2ac501-32d7-4885-b55d-08d8e2269619 X-MS-TrafficTypeDiagnostic: DM5PR03MB2634: X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 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:DS7PR03MB5608.namprd03.prod.outlook.com;PTR:;CAT:NONE;SFS:(7916004)(4636009)(39860400002)(136003)(376002)(346002)(366004)(396003)(6496006)(54906003)(85182001)(26005)(83380400001)(66476007)(33716001)(9686003)(5660300002)(66946007)(4326008)(6916009)(86362001)(8936002)(316002)(956004)(16526019)(6486002)(186003)(478600001)(2906002)(6666004)(66556008)(8676002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?eDFBdGN6L3VOTFcwRTh2R3RPVGdiYXBwTlJ2Qmh2S29MNFFlOER1NWxFODBM?= =?utf-8?B?WVMyRUZEd2pGQmxsUG9pYi9Cb0Y2L0h3R3gwVmRRa0wrS056anUyVi9ubXRD?= =?utf-8?B?b0h4aDVxV3hjRk5pT2UyY1UySnp2KzhuYk9WZ1J0TTlVTFd5cSs1LzFTNXBZ?= =?utf-8?B?TVpzbE1SLzl6UlFsMytIT3Z6S3VhR2lUL2FvbUlnaTVlYmgzNlpVU2F4Wm53?= =?utf-8?B?VmdkdStLU3RPTDZjOFNjNWlzSnNoTFNmWWEzcGJvaVc5TS9Ecm5rOUVSNTcw?= =?utf-8?B?VzF5V0d2UnNZVmRnNkdLYzhBdVRuS2ltM2dGb2Y5QjlhWmx5bnJ0cGVCTVFw?= =?utf-8?B?OHpBOUJLQjQ5U2ZDNzZhU2NGbmg4bGRKV2I0TnVGUGJJaHp6RlN2SVptWXhI?= =?utf-8?B?eTBzNmlSamRrenZoeGU5S3BLQWg0YVQ1Y0trcDZqVnZDaHViMHNSWks3b1k0?= =?utf-8?B?WUJ1TGFPdlBKYnUrWnpUYjJOcXF6OExvMExiZC9LWUMycVNTZ2dXdnJ5RURy?= =?utf-8?B?T3hST3gzMFdBVkE5dmc4bVFZdzIzTE8xMXhhWldtN2dGVFIrME1aYlU0YS9s?= =?utf-8?B?Y2pJcDh1WDRqQWZNQm1xUk5mMDh4aGg0bVhlRWFSMU55WDhTcnlVT1BKYWp5?= =?utf-8?B?TTQ2QlJxT1BQaDNUREJzZWdmWXdacElHaTRsWWZsM2lkL1A1NjdtOG01RUdv?= =?utf-8?B?WWpiT2l3Y0hCZGlLSmtIekVLYTZZejl3NXoyOEY1QnJPeHFlRHNpQVVWNnR4?= =?utf-8?B?MG1pOXNWcDlxOENPa09YU25ncktuZlJkVzlFVjNlRjl0OC9abzhNQ2dUcjI0?= =?utf-8?B?dFEwSXBrbm0xdDhsa09tQXhhb00veFNkejdzcStFYmxvWWl3ZTRMNFNLaVZm?= =?utf-8?B?YmpnUEdib0I2S2xwODhrejFkd015OWdNSE03SEN4cXJzWHAveW4zc2ZEYVdl?= =?utf-8?B?UFFidE9IQ2lhUXFoN3piMDQ3VHV0Y09YTXJyYmhpVW1sc2d0UGZrTzJMNXBR?= =?utf-8?B?ZE1aQStzV0VGU2p2QTlKMU9jcDR0SlFMNnJJa1BPY1BhU0tINzJSaEtERlJN?= =?utf-8?B?SFlRaUlLU2ZFem5kbUFWU3dLbm1yZ3loK1NhbUVoajVwYVowaVY4QUJOdHZP?= =?utf-8?B?RXpXMS9CaDZRdldMRGdQMXptZmg3WjJDa3piT1l2WU5GWk9uWGdXOTdzMFF2?= =?utf-8?B?dTF3dDlSSmpLVDZSNi9IOEFRbGhIdUU2N1RjK1ZYZVpUVkV0VE1XMldndFha?= =?utf-8?B?RDZyZW1MOUFxdUJLUXZPYWw1YUZLOUtCQ0sxaHVqbUl1czQ2UTJ6S0tUVHZv?= =?utf-8?B?N1BqbHlaV3drOENSZExpaEZOOVI1ODFWNStTYVFyc0ZEdUNDcDBad2U5U0U1?= =?utf-8?B?ZnZ3Y2JabDhNNTBQQUhjZHZveFhiYktUN3lBM1dQUGMyM3RZT2ROaFcxVmxJ?= =?utf-8?B?NGRTT05tN2ZBRFQvbDY1Y3hhcWVLVlJIY3pab2xOOC93bFdkMmtrYjhVUjZQ?= =?utf-8?B?dlEwYXhRMHI1bEdQbTA5cG56NlZmMVlFYllCMUJYemdZaUxPL2JEZ0JMOGpS?= =?utf-8?B?a21iV2E0MUFWc3FiZkR1M0NsVnZ1dGJFNXRmbWtSYWZ5K2ZocjRna1NTWFJX?= =?utf-8?B?ZEhqcGR1d2FwY0hJTlY1OEFYTm5sSXY2a213eHhMMklvaFRXNFg1S21VaE9W?= =?utf-8?B?SUFlbktFSEJCaXJRQ3BKeWtBK252TzZaZU1RRGwyRnUwYjZ1WHMyT0JFQVZK?= =?utf-8?Q?h16fL/oont2Xj1UqlG5XHAAAGftw5kDJ1m15D+w?= X-MS-Exchange-CrossTenant-Network-Message-Id: fa2ac501-32d7-4885-b55d-08d8e2269619 X-MS-Exchange-CrossTenant-AuthSource: DS7PR03MB5608.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Mar 2021 11:37:43.0116 (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: CK8gGA3Vj3evMoqo6PeNd02fSiHDPmFypT87IqzmeuchN62WjnqYi2s/hS0tUlm3x+hHyM8qbpCzV4XnQ3bR8Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR03MB2634 X-OriginatorOrg: citrix.com On Fri, Mar 05, 2021 at 10:50:54AM +0100, Jan Beulich wrote: > Linux has been warning ("firmware bug") about this bit being clear for a > long time. While writable in older hardware it has been readonly on more > than just most recent hardware. For simplicitly report it always set (if > anything we may want to log the issue ourselves if it turns out to be > clear on older hardware). > > Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné One question below. > --- > v2: New. > --- > There are likely more bits worthwhile to expose, but for about every one > of them there would be the risk of a lengthy discussion, as there are > clear downsides to exposing such information, the more that it would be > tbd whether the hardware values should be surfaced, and if so what > should happen when the guest gets migrated. > > The main risk with making the read not fault here is that guests might > imply they can also write this MSR then. > > --- a/xen/arch/x86/msr.c > +++ b/xen/arch/x86/msr.c > @@ -315,6 +315,12 @@ int guest_rdmsr(struct vcpu *v, uint32_t > *val = msrs->tsc_aux; > break; > > + case MSR_K8_HWCR: > + if ( !(cp->x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) ) > + goto gp_fault; > + *val = K8_HWCR_TSC_FREQ_SEL; I've been only able to find information about this MSR up to family 10h, but I think in theory Xen might also run on family 0Fh, do you know if the MSR is present there, and the bit has the same meaning? > + break; > + > case MSR_AMD64_DE_CFG: > if ( !(cp->x86_vendor & (X86_VENDOR_AMD | X86_VENDOR_HYGON)) ) > goto gp_fault; > --- a/xen/include/asm-x86/msr-index.h > +++ b/xen/include/asm-x86/msr-index.h > @@ -287,6 +287,8 @@ > > #define MSR_K7_HWCR 0xc0010015 We could likely drop the K7 define here, as Xen won't be able to run on K7 hardware anymore AFAICT. Thanks, Roger.