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 53C91C433EF for ; Thu, 16 Dec 2021 16:49:14 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.248113.427943 (Exim 4.92) (envelope-from ) id 1mxtw2-0007iu-Lq; Thu, 16 Dec 2021 16:48:50 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 248113.427943; Thu, 16 Dec 2021 16:48:50 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mxtw2-0007in-Ia; Thu, 16 Dec 2021 16:48:50 +0000 Received: by outflank-mailman (input) for mailman id 248113; Thu, 16 Dec 2021 16:48:49 +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 1mxtw1-0007iE-LL for xen-devel@lists.xenproject.org; Thu, 16 Dec 2021 16:48:49 +0000 Received: from de-smtp-delivery-102.mimecast.com (de-smtp-delivery-102.mimecast.com [194.104.111.102]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 09b5d842-5e90-11ec-85d3-df6b77346a89; Thu, 16 Dec 2021 17:48:47 +0100 (CET) Received: from EUR01-VE1-obe.outbound.protection.outlook.com (mail-ve1eur01lp2050.outbound.protection.outlook.com [104.47.1.50]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id de-mta-14-_iyWVJgFOFqjq_uviesjcA-2; Thu, 16 Dec 2021 17:48:46 +0100 Received: from AM0PR04MB5587.eurprd04.prod.outlook.com (2603:10a6:208:125::12) by AM0PR04MB4787.eurprd04.prod.outlook.com (2603:10a6:208:c8::33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4778.17; Thu, 16 Dec 2021 16:48:45 +0000 Received: from AM0PR04MB5587.eurprd04.prod.outlook.com ([fe80::9959:195e:46a5:d015]) by AM0PR04MB5587.eurprd04.prod.outlook.com ([fe80::9959:195e:46a5:d015%7]) with mapi id 15.20.4778.018; Thu, 16 Dec 2021 16:48:45 +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: 09b5d842-5e90-11ec-85d3-df6b77346a89 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=mimecast20200619; t=1639673327; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TqfQa9/wCrVuMkcpcsVM8531BUDQnVWVKZxdU3YhBW4=; b=XcCf59XG+eoGxrQ3grJbsqfWJO3LkYe6ml587Yhl15jHSeaZK5CjzyqzVomJl++iKqckaj FPhq1TKOx5wNOhoi0gRBmz+CqFWGsdFbdPza4Del9VMO06w/GpGJY07yhgFxevcIcDqPxv oe/HxcZQ+B02wAPpOzpQvWxHBKNj6eI= X-MC-Unique: _iyWVJgFOFqjq_uviesjcA-2 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=fHpE1GTRSj8cH4AH9tM3bZJZPq2xxJ1k7krHw/nQtL6ia/21V53eILK7EopM55VPCzq7LbtAxDI1GJqsVLFLA3QPVTs+kJr+WVNIBVR19N1FeFx+OSYeinAPCbe1u/9B1rkA/09jvxt1SpbQZW+hnEpLr1Rg0NPBn5jdgA4wPwAEhtP/hA9L8PebDcUb+5ZNMDQfTZwOTByjWkeFIIMll6hbu0b02hBD7mznttfzP0heZ+9rqtetZBuA6Dfx8BcXlHziJx03x1mVTZvqrOmxPugBBjXh3Z+QuT3spYInBff+lmOUX6UXmWcHqUiFbzYtz8vHay+O3cFL/bAruIlFYA== 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=TqfQa9/wCrVuMkcpcsVM8531BUDQnVWVKZxdU3YhBW4=; b=B+bfYG4tTvzBZJR5I8cQnJFQ86Ax6wnIIgSj4Sjh3GyhJ8TCUSBBUU5mvjTA+g3okLfcQtMHa9w0jrHM0DvOnAuxiK7+IUyopeaKsf6mmz73ylQDd+jNxsFBFwNNMe0Gdi6s52KWIZZ0mb/IaM4I8j77QzmOMwm1I14+mOPodcPITmI6vQySFZIHPyclQ7/DOeMWC8BEZr0ER53ftCpzrk+WBiA39ieioFw4scTkA+ITl2/ETnyNs5r0nuwTs0GGQ9JWRKSKE0MnaUZCwUM0LiT+pSPZ2LLwwbD8NCAcaui+SfIj4oOoleEUcX3li/X1h4HWNk1VRtWYCAH1tHEJFQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=suse.com; Message-ID: Date: Thu, 16 Dec 2021 17:48:43 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.4.0 Subject: Re: [PATCH v2 4/4] x86/cpuid: Advertise SERIALIZE by default to guests Content-Language: en-US To: Andrew Cooper Cc: =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= , Wei Liu , Xen-devel References: <20211215222115.6829-1-andrew.cooper3@citrix.com> <20211215222115.6829-5-andrew.cooper3@citrix.com> From: Jan Beulich In-Reply-To: <20211215222115.6829-5-andrew.cooper3@citrix.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: AM6P194CA0103.EURP194.PROD.OUTLOOK.COM (2603:10a6:209:8f::44) To AM0PR04MB5587.eurprd04.prod.outlook.com (2603:10a6:208:125::12) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 86159d57-8d0b-4c85-0282-08d9c0b3ec71 X-MS-TrafficTypeDiagnostic: AM0PR04MB4787:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:6790; 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:AM0PR04MB5587.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(366004)(8936002)(2906002)(66556008)(316002)(31686004)(31696002)(38100700002)(6916009)(54906003)(6506007)(53546011)(86362001)(6486002)(4326008)(83380400001)(8676002)(36756003)(508600001)(5660300002)(186003)(2616005)(66946007)(6512007)(26005)(66476007)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?bFBBV3k2TFZtdHE3YnB2dEp2YVVYeU8wTm5OTlZuUEc0T2VFNGgzOWxuRVU4?= =?utf-8?B?VDdXWHY5K01id0dHblNYZ01JMXZacEptK2ExTlEyN29MOFA3VjN3eVhvaWd4?= =?utf-8?B?QVhuSGlPU3NUNWwxQTJNZUFxeTJTRkp3K2Z6a1NzcUR6ZUJrdE44TGJNclhq?= =?utf-8?B?dUdBNU9raDE5ditEaHdHL0R3bStDWi9NSjI3SytjbGtzeHI5TUVNbUsxdWRE?= =?utf-8?B?QmxKaGJlWXdDejZyODN6d0hNcktBLzVaUC9RdUE3N1pXa3hhNlE2WjMwUUp5?= =?utf-8?B?ZEhaak9IZVhrVGZ6MG5Sc2cyaHJXQWpPdktGdWlaUmdubUd5UjZZb1FGRGpW?= =?utf-8?B?YmJwMktHMmZhcFQ3c3ptaTV2Y3lEY0pRa0hYVDRLeUpUNTA3U3czM0dqSWpK?= =?utf-8?B?WEh2Z0xjMldpMFU4N1VqS0cxUTIyMDc1UmRTWk1RS3ZyTlNTZFhXSkpPT1ZF?= =?utf-8?B?QnpWdVgxdUY0b2Z4RzhzTlJueDZVMVYwTTVESE1LcFRxbzlLcEFEd2xkajNM?= =?utf-8?B?VWdHbFZxNHNMbVZZQWdpMTJ3Z3MxVVRINzUzaThJeDdvMDBLako1ZzdtVUlV?= =?utf-8?B?aTJCOFRodE1adHlNaHZPOWtOLzZ3OHd0ZlgrTGdhWCtpajJ4Z0grVUhqUVBV?= =?utf-8?B?Z0VYcUJsZndudStGdGJvUnlyWTBLVUgxM0ZMZU9zTUk4MHJEU0lnajRxVzJu?= =?utf-8?B?czUzajQveTF3VHV2RkQvQ1NoSG1ENllJV3ZUbUxkc3RtdFZBRVd5WkFGcDhy?= =?utf-8?B?Z29IWDAzMi9TdjhzZXJoWXpCb1VwWHJCUlZyQ3Vmem5yeVp2cFlPZlNhWlBK?= =?utf-8?B?eWlMV1hXV3B4WGtvc2dFQmVBdldIUUVOYm1tcis4ZW4vMkRoK3VrT0tzVnQ0?= =?utf-8?B?cG93blQwYVNIMCs5akdGQ2FQR0dxdVk1OFdwRzN5ekkrTjNBVTJJNk5KOEpk?= =?utf-8?B?WWRtWVZxWFkrY0NCbnplT0NTT0JWRDk2MVVUTzRscG41SzQ0aTU4VGx1M3JP?= =?utf-8?B?cWphemtvUzFDRkFYc0JCdGtqZkFiVUQ1ekJmcmMydU1QZnZQb2FKbmpqMWJz?= =?utf-8?B?Wktzdnp2bGc4ckZORFpSTEYyT1U3TW9GVXUxRWNNU0VtN3ZQU1pEeFNFMnQ2?= =?utf-8?B?Q3JCNytGa2owMUJ1UkZTSGtIaDVjQlpIWDd2U3dxNng5Qk9zS3F0WGU1V1kw?= =?utf-8?B?QnVKOVFpWGdkb05NTEpVNWVaRTNoZXdOZ2NRQzU4T3Y2a1lnb0YxV2lMc3Ro?= =?utf-8?B?L3l0UGg2T2xTWFBjKzFqYUxnMElqZGYyY1ptVEI2TUFPYXRlOXR3MkQ2eHZ0?= =?utf-8?B?cThIY0UrOU5Qb01UZExYQ1V3alZzbjh1YzFyZU1EeUdtZXdGTW01WkJhMjVC?= =?utf-8?B?UDg2N1RYbjNkSExENmxyVVZNSFRHMDZoNS9RbGxQTWRlMVl4QlJEYjlpNURN?= =?utf-8?B?amQzTis3UXZQUHozVjV5bXFzZ0E3akpKbWlJblk1OExoQzM0bVQ2OEhOVkht?= =?utf-8?B?dFFZV2czRTcvMVEwVUk4YTF4aEFYenZadjlJY1RyNTF5Vkhmdld4K292Nkty?= =?utf-8?B?RTdMMEFTVVpaV1IyVDZ2d3MxRnlaZUF3enIxalhDMGNmYkF4Um04RmRvNlA0?= =?utf-8?B?UEtxYW45Ui9sZmtkZ0J4MGVuNkx6eHk3UjYxYUdjNGhjRENGSWpmZjJhTGlC?= =?utf-8?B?WEhoQk1HY0UxZ1VsejFHRVV3akl6OXFzd1NjeXRLWWwxdnhyakQreU9OR2V0?= =?utf-8?B?UlRBRENPUmJRRFREVmZTcXgvZ09PclZmdVhVb01JMTRwUFpmalJ2TnhpOUFI?= =?utf-8?B?Rys5M2xMMnNtLzFwMGhwbHVqeVY4bVFjK3R4R3UrNzVqdGcxNkZSSlNSMStz?= =?utf-8?B?WE10SlRaN2krdDYrRERFR3J3ZGs2djZ6Rys2Q0R0S3NoV1dFZE5RUnNHSmNh?= =?utf-8?B?bkg1ZE0vY1BnZFFBZG9TODZnUUw2OHFvbENqeGpPcnBYZDlhMUg0N2tJRDlj?= =?utf-8?B?UC9YL095SHNKMkkrOGJ3MVpsWTRWRjRwandJNmFQWGZGVnZzVEpkSDZqbS9X?= =?utf-8?B?a0RhM0oxMHNPaWlGSkZKMXhBQ0FNOG9HSU9yVE5zZ3NYQ1FLUENwcUV1a2FR?= =?utf-8?B?NzlhYUg5M3JpakpLZVhEZCtqeklCOFhsaVVVa2lIcVNZUlQwMVc3STRLZExH?= =?utf-8?Q?730/coRflTq9CZo2d77l/3s=3D?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 86159d57-8d0b-4c85-0282-08d9c0b3ec71 X-MS-Exchange-CrossTenant-AuthSource: AM0PR04MB5587.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 16 Dec 2021 16:48:44.9237 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: cx2s1cDFutFKKX7avH6Cpm5szMGzHm9A+eO7pXl8PakUoBnwR5ddLpGWy9KjPXtCK3phMPibMQ5SqkbatkQMSw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM0PR04MB4787 On 15.12.2021 23:21, Andrew Cooper wrote: > I've played with SERIALIZE, TSXLDTRK, MOVDIRI and MOVDIR64 on real hardware, > and they all seem fine, including emulation support. > > SERIALIZE exists specifically to have a userspace usable serialising operation > without other side effects. (The only other two choices are CPUID which is a > VMExit under virt and clobbers 4 registers, and IRET-to-self which very slow > and consumes content from the stack.) > > TSXLDTRK is a niche TSX feature, and TSX itself is niche outside of demos of > speculative sidechannels. Leave the feature opt-in until a usecase is found, > in an effort to preempt the multiple person years of effort it has taken to > mop up TSX issues impacting every processor line. > > MOVDIRI and MOVDIR64 are harder to judge. They're architectural building > blocks towards ENQCMD{,S} without obvious usecases on their own. They're of > no use to domains without PCI devices, so leave them opt-in for now. > > Signed-off-by: Andrew Cooper Acked-by: Jan Beulich