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 5BDABC433EF for ; Tue, 24 May 2022 10:49:24 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.336487.560811 (Exim 4.92) (envelope-from ) id 1ntS63-0005qJ-R1; Tue, 24 May 2022 10:49:03 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 336487.560811; Tue, 24 May 2022 10:49:03 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ntS63-0005qC-Ni; Tue, 24 May 2022 10:49:03 +0000 Received: by outflank-mailman (input) for mailman id 336487; Tue, 24 May 2022 10:49:03 +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 1ntS63-0005q6-87 for xen-devel@lists.xenproject.org; Tue, 24 May 2022 10:49:03 +0000 Received: from esa4.hc3370-68.iphmx.com (esa4.hc3370-68.iphmx.com [216.71.155.144]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 1e8e2f87-db4f-11ec-837f-e5687231ffcc; Tue, 24 May 2022 12:49:01 +0200 (CEST) Received: from mail-bn8nam12lp2174.outbound.protection.outlook.com (HELO NAM12-BN8-obe.outbound.protection.outlook.com) ([104.47.55.174]) by ob1.hc3370-68.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 24 May 2022 06:48:57 -0400 Received: from DS7PR03MB5608.namprd03.prod.outlook.com (2603:10b6:5:2c9::18) by BN8PR03MB4996.namprd03.prod.outlook.com (2603:10b6:408:7e::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5273.13; Tue, 24 May 2022 10:48:56 +0000 Received: from DS7PR03MB5608.namprd03.prod.outlook.com ([fe80::5df3:95ce:4dfd:134e]) by DS7PR03MB5608.namprd03.prod.outlook.com ([fe80::5df3:95ce:4dfd:134e%5]) with mapi id 15.20.5273.023; Tue, 24 May 2022 10:48:56 +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: 1e8e2f87-db4f-11ec-837f-e5687231ffcc DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=citrix.com; s=securemail; t=1653389341; h=date:from:to:cc:subject:message-id:references: content-transfer-encoding:in-reply-to:mime-version; bh=+CB5XIBTxl9KpqOWXK8UUMxWOY2QOatU/TBa81i8ESI=; b=evQIjKhOn8GXslzS8bqVgiLd9svFQ3xy/kJLHPKlbm94VfNsELXQDXEQ r770cggqP6EBUKEK3tgxyn44mQloZo0ACLibJGemZ3iici82qNzYYaDyv 5Q1zsAq+p6z8zY3Xdg1ESd8aNxvRd2KX2lBKTHH+stoDscun/XVW8DWCU U=; X-IronPort-RemoteIP: 104.47.55.174 X-IronPort-MID: 74553686 X-IronPort-Reputation: None X-IronPort-Listener: OutboundMail X-IronPort-SenderGroup: RELAY_O365 X-IronPort-MailFlowPolicy: $RELAYED IronPort-Data: A9a23:P5zaLK7emVpsYGy0/5zMigxRtEzGchMFZxGqfqrLsTDasY5as4F+v jYbXG/TbPjZM2SjLY8jaIuxo04EvZGDm9BmSQc5rC1jHi5G8cbLO4+Ufxz6V8+wwmwvb67FA +E2MISowBUcFyeEzvuVGuG96yE6j8lkf5KkYAL+EnkZqTRMFWFw0HqPp8Zj2tQy2YXjX1vU0 T/Pi5a31GGNimYc3l08s8pvmDs31BglkGpF1rCWTakjUG72zxH5PrpGTU2CByKQrr1vNvy7X 47+IISRpQs1yfuP5uSNyd4XemVSKlLb0JPnZnB+A8BOiTAazsA+PzpS2FPxpi67hh3Q9+2dx umhurS2YloDOYGSnd4RCTZiEypsFIJX2+/IdC3XXcy7lyUqclPK6tA3VgQcG91d/ex6R2ZT6 fYfNTYBKAiZgP67y666Te8qgdk/KM7sP8UUvXQIITPxVK56B8ycBfiXo4YHgF/chegXdRraT 9AeZjd1KgzJfjVEO0sNCYJ4l+Ct7pX6W2IE9Q/O+/ppi4TV5BFf2eXHN8TzQOGDAuRvo0qDu mnbo3usV3n2M/Tak1Jp6EmEhOXCgCf6U4I6D6Cj+7hhh1j77nMXIA0bUx28u/bRol6zXZdTJ lIZ/gIqrLMu7wq7Q9/lRRq6rXWY+BkGVLJt//YS7QiMzu/e5VafD21dFDpZMoV56IkxWCAg0 UKPk5XxHztzvbaJSHWbsLCJsTe1PitTJmgHDcMZcTY4DxDYiNlbpnryohxLScZZUvWd9enM/ g23 IronPort-HdrOrdr: A9a23:KIAjpaM4bcLGecBcT1P155DYdb4zR+YMi2TDiHoddfUFSKalfp 6V98jztSWatN/eYgBEpTmlAtj5fZq6z+8P3WBxB8baYOCCggeVxe5ZjbcKrweQeBEWs9Qtr5 uIEJIOd+EYb2IK6voSiTPQe7hA/DDEytHPuQ639QYQcegAUdAF0+4WMHf4LqUgLzM2eKbRWa Dsr/Zvln6FQzA6f867Dn4KU6zqoMDKrovvZVojCwQ84AeDoDu04PqieiLolSs2Yndq+/MP4G LFmwv26uGKtOy68AbV0yv2445NkNXs59NfDIini9QTKB/rlgG0Db4RE4GqjXQQmqWC+VwqmN 7Dr1MJONly0WrYeiWPrR7ky2DboUITwk6n7WXdrWrooMT/Sj5/IdFGn5hlfhzQ7FdllM1g0Y pQtljp+KZ/PFflpmDQ9tLIXxZlmg6funw5i9MeiHRZTM83dKJRl4oC50lYea1wUB4S0LpXUd WGMfuspMq/KTihHjPkVyhUsZGRt00Ib1m7qhNogL3W79BU9EoJunfwivZv20voz6hNOqWs19 60TJiAq4s+PvP+TZgNc9vpEvHHfFAkf3r3QRGvCGWiMp07EFTwjLOyyIkJxYiRCe41Jd0J6d 78bG8= X-IronPort-AV: E=Sophos;i="5.91,248,1647316800"; d="scan'208";a="74553686" ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Lmemz62kWwu9+lRpPU0fvE3q8fxVBXSb6U2yTbpTsImKBSB63oxo5pxVHoPL4R9B8wxjiLfYD3whOf7a9qQp+lSVmRUi2ivJhKJrss1fIqitaxY+UGXDe4a1OIJOdo6iHi5yJAx4t0opWGrEq7Ot2l0QxUf1gw1S1CJu09DWTFgW0glKR4LeLyld75/b3c49eFUon3cK7bzBtgy0De4cug0t4vjQcC6o2RThMvuZLQXJUMjsktZMQtWjZE0gYZHYki19al0PZ+83q331Ip/P0Q8xkXDGTAYo8qoF36UnTvsBG03o36GCipwb56wOXLH0ezkKLzRDfDpnXUqQ3sghOw== 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=ZkkL8uFAuJ6LjMwJxMrbILLKOgiqgw1iWo7SKl6Jy/U=; b=DVSok2xyoH3GRNA5Nsm/dsWA6rsUktd8KKulXKTU8HoRUKG5ocTuv6/sCEd1smI4wfNO40DKCXv2Hqk3HG7+FgGuPGxyv9GVxRs98r0N7yssorB0H6kXAu7CbK5hAI51oRmox0QiJB9rJn37sqHG33JjVbA9lRu4dJ6/hwhw5NuzzN4efeTKavMeRRC/ln0oLfl5Biru1CKf4F89s1zEjIZkih3qfvOJ0JD2ZqbLhx1+7IpeCG7aUU77iI++OTvExUv/mRZGSi7RBcRDhkiyDZvHeIZ9rOgUuePn14U7PKrtxcmITvQtZSm+HBB6x1Xmuv0YUQQY4LzshPUnJqRlUw== 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=ZkkL8uFAuJ6LjMwJxMrbILLKOgiqgw1iWo7SKl6Jy/U=; b=liEyap+wpWFCmBAP90WT2+S+xc9hicJpnjsgymP5oT6zHHiez2vVWWFDkJfbnEezoXvdmVh44nb+7t1O32hCQOhMTaWh1lHO9zixExUOyV7MipGag8M8S9Mbqe8ghsy1bVq6jMHJdtybMzWHUajatn7hH+ib7p23TYi30AYZtcw= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com; Date: Tue, 24 May 2022 12:48:51 +0200 From: Roger Pau =?utf-8?B?TW9ubsOp?= To: Jan Beulich Cc: Andrew Cooper , Wei Liu , xen-devel@lists.xenproject.org Subject: Re: [PATCH] x86/flushtlb: remove flush_area check on system state Message-ID: References: <20220516143116.28602-1-roger.pau@citrix.com> <4b025fee-8f7e-1849-184e-1be8fb99442b@suse.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: LO2P265CA0429.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:a0::33) To DS7PR03MB5608.namprd03.prod.outlook.com (2603:10b6:5:2c9::18) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a371d541-9217-488b-00d2-08da3d73001b X-MS-TrafficTypeDiagnostic: BN8PR03MB4996:EE_ X-Microsoft-Antispam-PRVS: X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: GczZVGx6UJsMGFeoHP3oZshVdAf1748xO6WnjZ0jlh2xEbGQ4Vsj8YOnNyZ22rt97eUdB+fR+aMz9rKSzVfjjytVCrmqYKykJhl0IoQD5cd8CbNbpSAFbBAjRU5Z2/TNEdMKDudIRiu7jyw8TVM7g7rCULv9as/Id64thKizh3t3Gvk6+nQR8F6CN+1BdGUnmgsxb8fMIPhJloWXWE5+H0nIkg0EzUdh+jNHrsH3V6iSpOzB+aINGqUQJwUBb1mjyZbtIJcAPuquJNKn5vUPs+Q8ASYz2Ft1i3HIsa0PpbJZSYSZWmfw6Ujssw2X9a74jkfIc0yjMwlzfwrAo2wnD+1IuoIVW91iXrq09cTTpZ19nar93+hjC8bLTBBuakXTCaig50YIEYdBiLiPlEcLUMt+wc2Jh4ZZuO+ep3TY7e4sJtA8ZPv9BbEjsFTAlkyYQfxqNL3MyBCrDW+bZrvIF0jE1bMha4fV8ymAGBgWBw1sWY3HF+lveU7uQyeiGJCXbPtVWai5FPz6SYtPWqfCBfJdt67P8+xC0LOZld2MnwEjZEdqhO1n+2pYHwgG1+llApMKBG2eoFFl46DAxkub/FlIq7/z3evCBcN2/WZxOHUryfO7zuS0tDtdHEnuObJLZ5WEOpYP0zpWxp2vzSi02w== 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:(13230001)(7916004)(4636009)(366004)(6512007)(6916009)(54906003)(186003)(83380400001)(26005)(6506007)(53546011)(9686003)(85182001)(508600001)(6486002)(8936002)(5660300002)(2906002)(66556008)(66946007)(8676002)(4326008)(66476007)(82960400001)(6666004)(33716001)(316002)(86362001)(38100700002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?WS9wcTZ1ZWtEdjFCQWdjNWE1N2FxTGRrYUF1dVZGZ2wvM3FNcEFmK3JHR2Jw?= =?utf-8?B?R0ZTMzlzMWloL1MzL0c2Wi95NmVpYUtBd0NDd2RDWTlwYStFY1UzUzRoYTJC?= =?utf-8?B?b2gxN1NLbllZU1kwdmlJalZ5dEtBa1Y5aXA4elphTGVwTEtER3NQSU1DNitt?= =?utf-8?B?UndxQUU1YWQ0TzF0aW5VQmc1ZitpbjRPbXBPaDZDSkNPU1F6RkJrNEhGM1ll?= =?utf-8?B?czZtREtKTmIwU2ZOelZKYUxSREJGUlVTa2lRb3JLNXprL1M4SnpjWjBWVmhn?= =?utf-8?B?cUlJeWJxaHdjSWRjekFHU0VZTFQ0N1RHK051SHgzdEMzYWZTNENGWERwbEl5?= =?utf-8?B?ZUpZaUNPMlNwTXBselRKN2liNzNGcFU4VlVwMk9iWkZ1OHh2Nk9DWU5Vd1RS?= =?utf-8?B?N1dVT2Nic3QvdjhmNmFPZE03bjNIeEs2TGpHMUxjQ2dNZHlOOGdaaUJ0cWNm?= =?utf-8?B?TFN5Uy9uaG1jZGRRL3FvZU8wbGFzaHViL1hQekVlQUdnSDM1Y052SEZmMEJT?= =?utf-8?B?M3pmQkF1bDVLdzlyZHpOKzk5S3Q5SUNPZG1nbXYveExLaGg4dWtuMURSVVll?= =?utf-8?B?V3RJWlBFVWhtNStkZitNcGpzTDVoSEtGVVpsdEw5MHNnRFFUWjRHVnUzeXh4?= =?utf-8?B?MTFHUlBsWU1UMTNOS29RRi9kSUFvREFNb2Y2ODJ0TDJSdkR3RkJ5SWk4bUlp?= =?utf-8?B?c0tNM2dwOHl4T2pwZmZaNHQzV3RsbTJZQ2M0SWRtQjJlNkhONXNxMUF3ank5?= =?utf-8?B?NVZaSjk5bDI4ZlRwK0ZITEZNcEl0Qm5LQXFpNUlmOERnd1Y1b3hEOVE3d2Vh?= =?utf-8?B?ZHYzZW92eSs0d1JsdHdSV2pTWDhHMXZhUlk3ZHI1ck9Fb1QyOHJQWC9wOTNz?= =?utf-8?B?OVdFbWZ2ZzhGWWtLSk5jb0pYMnpBbmR6RzZuRTAxTkhqWGtEYmN1cng5VXRO?= =?utf-8?B?RitYSTdTVFJQbHFXY0hHYy80bzV1WnFsUWRWeUwrejA1Rll1OGtqRDQrNWtO?= =?utf-8?B?bDE5TlNJcVZlOWxqelRPSXZSNWNzL29IYTA0Tzl5RSt4Q3lWblZ6SHY0VVB5?= =?utf-8?B?N0Fvb3FscXMwTlMzdnpNbFAzLzlBN2tKWHRRVDFIS2xaWGxwelhhSHFIcFAv?= =?utf-8?B?ZnU4aTdXT1k1S3ltTXJOVmFnVklKRFhUZW4wZjVGam5MaDIwaTZLQ2FNQjQx?= =?utf-8?B?Sld3N2FDOUhCZ3hFUm1uMitHWFBVUExUTW1FZE1CNU1Gck9pRGpqU1ZsZ3k1?= =?utf-8?B?cU9vU0k1ZEVVeFpSMGJ5UDVNUFZ5akFDbVJkMEY4N2dVNyt2R0N6YVM2ZUdQ?= =?utf-8?B?a0R5S3ZzbzJoWmEwL0s1MDQydWplV3NMT1Z2bXY4V2VVdXZYblZhV0J0a1Y2?= =?utf-8?B?b2FqbUdlb0RvMzNCNmc0VVdMcFJRaEZsdm52VENkeW40WFM0QWRqTFZDejRs?= =?utf-8?B?bzhHU3pyQXdYWHZVVTZWSlZBbTEwWGZzZFIyUitCaEdoWTFzQ1d0bVpmWjdQ?= =?utf-8?B?OXM1d2tUalVvQnZRenEybkc1Q3cwdms1VGx6S0dLOHdjTGZGMHpnUFZaT09w?= =?utf-8?B?L0tlak9WR081SDBteElDMkpnWi9wNGlpOFBiQVlXMnpWb0N6TzZMZHRiQXVQ?= =?utf-8?B?NnhPZEs2TWt6ZG1yaTRNMlRST3pZM3FyamhxUXgvWklXeHl4L0RRUVFKTkNi?= =?utf-8?B?OW1hNzRuZ2p2MU51RFM2STcvRGJsc2lkMllsem5BS3ZkKzhtTW1vRmJ1cnc2?= =?utf-8?B?TGFGMElLVWlaMzd3SEo2RGJXYWVxUGRJSWF3cTNFejU1d25FOUwrTFNFcndx?= =?utf-8?B?TFl3OS8yUkN4NzFlS3F6cXlEVVlINEUvcG5IL3ptMENpdGFzc3ZGdXNOMWtk?= =?utf-8?B?TmN5allLay9aM29rajFZWndYK25BTnpSam4zRkNORU5nbGhaN3M2Sm9zRGxi?= =?utf-8?B?V3lmK2hKamJlc1g1dmExWGpXWU52MHBUS1VpelQ1R3ZoZjM4ZVg4dndva2dQ?= =?utf-8?B?eTFnOW5HcHNIa0k3N3JNR1dCNTRaQUVKMjR4YlUrOEhCMFFIbmR1SGVMejlw?= =?utf-8?B?bW9BWjA5cjNQa0JLYVoxNWI1b0p5YjBzRHdIK2ppbzFuUWpHeU1MVVdLTDhp?= =?utf-8?B?S3laZzFVUFo2aVZGSU8xS1hmTGl0NHZ3OHFPZGE1WGNEZkUxS2RCYnJ0blcv?= =?utf-8?B?dDBVM2tiME1JcWt6QzRHdGdiRUo2WUE0VVNCMENkM3hjb0p6TzhZRnBmdGlU?= =?utf-8?B?NUlPNy9UTHFaUU5IYWtMSUFRS05GSjV2QWRJOW9Ed20rL2tYYnNvVTdaSG1M?= =?utf-8?B?d1ZPTmlONzdxNHJYRWpFS1hQY2s3TnlnL3ZTUWxUb0hmNWpUdFUvZVoya3JU?= =?utf-8?Q?eGzqXrj93yxb6wWg=3D?= X-OriginatorOrg: citrix.com X-MS-Exchange-CrossTenant-Network-Message-Id: a371d541-9217-488b-00d2-08da3d73001b X-MS-Exchange-CrossTenant-AuthSource: DS7PR03MB5608.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 May 2022 10:48:56.0524 (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: EzkxdSv+Wv96GDEVR6VwLrIXU86npwFId2erxXQKZF4NVQZgb1KWNx0qqPKvS7pfi/BaUqzW3H38bRvuJjHrZg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN8PR03MB4996 On Mon, May 23, 2022 at 06:24:48PM +0200, Roger Pau Monné wrote: > On Mon, May 23, 2022 at 05:13:43PM +0200, Jan Beulich wrote: > > On 23.05.2022 16:37, Roger Pau Monné wrote: > > > On Wed, May 18, 2022 at 10:49:22AM +0200, Jan Beulich wrote: > > >> On 16.05.2022 16:31, Roger Pau Monne wrote: > > >>> --- a/xen/arch/x86/smp.c > > >>> +++ b/xen/arch/x86/smp.c > > >>> @@ -262,7 +262,8 @@ void flush_area_mask(const cpumask_t *mask, const void *va, unsigned int flags) > > >>> { > > >>> unsigned int cpu = smp_processor_id(); > > >>> > > >>> - ASSERT(local_irq_is_enabled()); > > >>> + /* Local flushes can be performed with interrupts disabled. */ > > >>> + ASSERT(local_irq_is_enabled() || cpumask_equal(mask, cpumask_of(cpu))); > > >> > > >> Further down we use cpumask_subset(mask, cpumask_of(cpu)), > > >> apparently to also cover the case where mask is empty. I think > > >> you want to do so here as well. > > > > > > Hm, yes. I guess that's cheaper than adding an extra: > > > > > > if ( cpumask_empty() ) > > > return; > > > > > > check at the start of the function. > > > > > >>> if ( (flags & ~(FLUSH_VCPU_STATE | FLUSH_ORDER_MASK)) && > > >>> cpumask_test_cpu(cpu, mask) ) > > >> > > >> I suppose we want a further precaution here: Despite the > > >> !cpumask_subset(mask, cpumask_of(cpu)) below I think we want to > > >> extend what c64bf2d2a625 ("x86: make CPU state flush requests > > >> explicit") and later changes (isolating uses of FLUSH_VCPU_STATE > > >> from other FLUSH_*) did and exclude the use of FLUSH_VCPU_STATE > > >> for the local CPU altogether. > > > > > > If we really want to exclude the use of FLUSH_VCPU_STATE for the local > > > CPU, we might wish to add this as a separate ASSERT, so that such > > > checking doesn't depend on !local_irq_is_enabled(): > > > > > > ASSERT(local_irq_is_enabled() || cpumask_subset(mask, cpumask_of(cpu)); > > > ASSERT(!cpumask_subset(mask, cpumask_of(cpu)) || !(flags & FLUSH_VCPU_STATE)); Actually, it would seem even more accurate to use: ASSERT(!cpumask_test_cpu(cpu, mask) || !(flags & FLUSH_VCPU_STATE)); Thanks, Roger.