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 C8B8BC433FE for ; Tue, 24 May 2022 15:28:03 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.336610.560966 (Exim 4.92) (envelope-from ) id 1ntWRi-0007qw-RD; Tue, 24 May 2022 15:27:42 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 336610.560966; Tue, 24 May 2022 15:27:42 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ntWRi-0007qp-NT; Tue, 24 May 2022 15:27:42 +0000 Received: by outflank-mailman (input) for mailman id 336610; Tue, 24 May 2022 15:27:41 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1ntWRh-0007qj-8O for xen-devel@lists.xenproject.org; Tue, 24 May 2022 15:27:41 +0000 Received: from de-smtp-delivery-102.mimecast.com (de-smtp-delivery-102.mimecast.com [194.104.109.102]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 0bfeb602-db76-11ec-bd2c-47488cf2e6aa; Tue, 24 May 2022 17:27:39 +0200 (CEST) Received: from EUR05-DB8-obe.outbound.protection.outlook.com (mail-db8eur05lp2113.outbound.protection.outlook.com [104.47.17.113]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id de-mta-3-PwKQD3DuN4ODNTMmzeTALQ-1; Tue, 24 May 2022 17:27:38 +0200 Received: from VE1PR04MB6560.eurprd04.prod.outlook.com (2603:10a6:803:122::25) by AM9PR04MB8953.eurprd04.prod.outlook.com (2603:10a6:20b:408::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5273.23; Tue, 24 May 2022 15:27:37 +0000 Received: from VE1PR04MB6560.eurprd04.prod.outlook.com ([fe80::91b8:8f7f:61ac:cc9b]) by VE1PR04MB6560.eurprd04.prod.outlook.com ([fe80::91b8:8f7f:61ac:cc9b%7]) with mapi id 15.20.5273.023; Tue, 24 May 2022 15:27:37 +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: 0bfeb602-db76-11ec-bd2c-47488cf2e6aa DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=mimecast20200619; t=1653406059; 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=29N3yclwzPgKiRCnJIOY0AYd2tH9ld7ttxwK87jtz7E=; b=DvjbFHDqo6bsNYWOxNeno97GDK50i3g1sJeimWEJkbBCx14OrUWWuqSCJhsX0BlYbcRir8 CUaxySolA1uCjm0wjH9b/EZP72aB3PhJDGJfUWrcOagkkVi5od6j58UFTv7dNEMUI69Df2 mjAkZP/0J59r6bVh/NbQnqaprnpQw8Q= X-MC-Unique: PwKQD3DuN4ODNTMmzeTALQ-1 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=SBP2/fKoEqW24Ugu8yRPkOIlXQqT/X/oVOlMoVvx6OzN2H77wcrJYG5N/rB8wY4Gj3ce5govw/AD0XcgekeCD1Q2Q91X9+uZUNGiI7Y52SGbcyTUlCbZKUBD+Lw6ymb5+U5LoxABvBnhZbrwFre+sW3G3DPzZhz5oa7lDyQhuaawSx1t2wXTCWRLyBtAFbv8hAue5o6Fw8mAFOPMlt4Ti3ahcM5Jq/aTnFNaNXQdXAUoucjA7eBH60+gzfUHemrqy792raK71SLUEww/pN3HbzyorsfIvVXQYW45Lz7z3sSgMgkj7/ttpLvNh/Prnhx9F1vJizYMS9vfCs1Gu/r1/A== 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=29N3yclwzPgKiRCnJIOY0AYd2tH9ld7ttxwK87jtz7E=; b=UIOMqOQ0VIo7H6kn50k0JYwiE6GuaZZiRxuCMBSxAm596Ra1o6uO2UMuh0yke+lRShQqh65Dsehc//4IsFxHjVgIT/rCxyfI34HwPNYw2TTpGaL1L9qbW3KFkabkK2xac+KL0H6yNRy3nUc/vaMmhyHclaKUgYqCOVy6YpH1+iII+NFdwR+iL+ihSLACJUwySPNHKiHsS4wFyAaINbwRUYk8sgnNWokfgHmB82zaCrL79n25anH++vcdVGqgwr3gBT24eIEo36qF5bjZwR7oaD8fqzZo+fARh/ZknprkTlauZZYDynRnnR761I4Ya76+QQPqIzVqJwUBJLlrIL5qTg== 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: <1b0b643b-a906-13ba-d414-feedc98428d3@suse.com> Date: Tue, 24 May 2022 17:27:35 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v2] x86/flushtlb: remove flush_area check on system state Content-Language: en-US To: Roger Pau Monne Cc: Andrew Cooper , Wei Liu , xen-devel@lists.xenproject.org References: <20220524105052.5210-1-roger.pau@citrix.com> From: Jan Beulich In-Reply-To: <20220524105052.5210-1-roger.pau@citrix.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: AM6PR04CA0010.eurprd04.prod.outlook.com (2603:10a6:20b:92::23) To VE1PR04MB6560.eurprd04.prod.outlook.com (2603:10a6:803:122::25) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: a559a7c1-1dde-41ce-b372-08da3d99eea1 X-MS-TrafficTypeDiagnostic: AM9PR04MB8953: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: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VE1PR04MB6560.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230001)(366004)(66556008)(4326008)(66946007)(6512007)(8676002)(86362001)(38100700002)(26005)(66476007)(31696002)(6506007)(36756003)(31686004)(53546011)(316002)(508600001)(6486002)(6916009)(8936002)(54906003)(186003)(83380400001)(2906002)(5660300002)(2616005)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VUNSRktSdFBwSnNUZnJnRnM1a3h2dzFPSGpUb3ZWS1E1V2lwNWdDU3VqSUk4?= =?utf-8?B?ZXN1TWo4bzNoRmR5cDZocnIvYm0zLzh5bXdZdHU2d0pqUE1zYlZyck0rT0U1?= =?utf-8?B?eTB0ZEtrQTlkV0l1VWs2VmhEYXU1djBGaWNVdjlTazdSTm5pZjRiR3RCRUsz?= =?utf-8?B?dm5CTGhTeWdUT0NTTkdkWUt5UmQrZExaRlJRSzJVanVtaHRBYnVSWjVHcGQw?= =?utf-8?B?cllPb0R6aTFnbXVWTndVWTFnV29zWU5UblBzb0xDN1NIeUZkUTZGWmxFK2F6?= =?utf-8?B?RmpobHdJdkMvRWZoQzhCZFltaHgrdTcvRURRalAwNEp1VnB2WkJmdTFLbURy?= =?utf-8?B?bi8yZzVUWHcyNmFHalpRQXlMdUJMZnloc29wNytWUVJFcFgyRlRQMXpzaHRG?= =?utf-8?B?MmtJcEYyMXNNd3RpUXVLelN3aWVqNENGSmlzNHBGY1VXZHZGLzFoNDN3QlVS?= =?utf-8?B?N0JOSGxxL2RtTjJsZmRGUS85YzdkQThOdWNDU01zUHVPWWJLZ3B1L2RObUNP?= =?utf-8?B?SHJPejEvQlFpVGJOTkNCUzhoSGJmams4RDluaFZaWWxhcnFFN2dEWWZ3STVS?= =?utf-8?B?MVZmNUlES3dOaUphNzVvelNBY3lEOTRmMFZjSCtWMnA1eEc5NWlJUXkvbXFs?= =?utf-8?B?QkU3eEVWWStuMTU4azZOcUw2UjV6dnJrQjFYMW43dHNkZVUzVERmOFR1eE1k?= =?utf-8?B?a2NWdnpCUkp6NlRrVXp4eWZaN0FhWGVsWXd4MjdxZ1YzT2V6MzAzM0VoaHda?= =?utf-8?B?cUJaVEMxd0F5Y05uKytQVjU3TFhndm0wOGFrSVBjL3NYN3lyZkxHWEdhaUF4?= =?utf-8?B?d3RHSDB3b2hwcGNocTUrTS9vTFFjcXR3a2V6aTBqd0Y2RkJkM2N4NFlMUzdB?= =?utf-8?B?dU1IWlQyNUprR2V2VDdJRG9yT3lhRnNLOTBxa0ZXUmpVVEVodkJpZ2pibk1H?= =?utf-8?B?TElPZXBORTdpVm11N2lmMmdYcktZdUR1N2RSUFF5M3FtRFZQUVBIWXI0cmJo?= =?utf-8?B?bG9nRnZvc2RRSlFRWmwySjdSdU1zdE40SGU0dm1maXdDUzdkV0FvZ2RRazdN?= =?utf-8?B?TEhaUDdpWjA2UDNERkVvK085U3lqcmZIbWY5dmZkU3ZvMVg2M2h4STBsY1RC?= =?utf-8?B?dzVGdjZhU01BMTZ4di9hMHZ0alA3cWNYMmxQVkVvckh5bzdpTStQNzIwNHlX?= =?utf-8?B?VlVxV0c1WUhLMDJHQUVuSDVsNlUvMlFjSWJFenZYcFlzVnpaeGxldmtGemdF?= =?utf-8?B?Y2pqMDFic3AxbDhxWnRyMzg2bVdhNHk4eUNnRFZ4TXVrOTh4Z2swNFgzUVJY?= =?utf-8?B?Y3p4RVlSWDZIQXlRcjV3T0lnVlJ5SlFWMjQzSTJMSVRpZmF5Z0R6T2s2ZXha?= =?utf-8?B?RVlQZHNuNGRTU1RITTNFa2c0YmQ3QWhUUy9TNEsxVDR2bzlwT1dOMlR2WTkx?= =?utf-8?B?NDZUeWRMZGxhdXBsTkc0b3UwVzRrbXFoOW9wUW5HMUZhTjEzTDJMcm1sQTkx?= =?utf-8?B?NWp5RlQ3UG9SV2U3K3VmQXhtbUZ0ZlJONFZmRDZvWnFYOUV2OTZyVGpqTnpx?= =?utf-8?B?N3M2Y3lsdGpucStzanBVREY4c1M5VjBPZllOa2phbmwrTnpoRTdpOHBDV3JB?= =?utf-8?B?dkRBNGgyUWxhTDNINjJZemM1cHRaRXFxTkhKWklrbmdobEVyRUFSeXVBbEJx?= =?utf-8?B?S0lTRS85RjVlcXB5MFN0U2dHTldpWmcydFZESlpoK1ZsVE8rTjg2bEI3SFNW?= =?utf-8?B?bzVXdG1iVGkySURoT2ZqbzdCYUpMSTJYb2VrTXNhRmdJT29ueDcySTdlM3Uy?= =?utf-8?B?cjNIRnFUSTlOTGE5UndST0lZTmhmU1laUmx1R2dkekhIZGg5TStEbzJRaCt4?= =?utf-8?B?YlMrcWhtT1BJSHVybUUwMVFuRnU3US9BR3lSSFFhUzlTMEF0ZkVFODRFQVBI?= =?utf-8?B?SFlYMjlQWHlFSHlIbEdlblhUelNWWW5hbGV1a2FOby9GcEtrYVRwQU9teUdx?= =?utf-8?B?bVMwaXJZVkJQaWdvQitJaE1KSEkwYnkvZXN6ZEw2MERzaC9BMGZWSG8zc2NR?= =?utf-8?B?ckZEbWV4cnhxQllhbjJzOUU3aGp6SXhTNDNkbGJCTjlOeUFQOXBGeDZSYWNh?= =?utf-8?B?dzZRSVhUMkpiazdiaWVXSU1uS2Z1MU1zcExRRGYySGd6OVJ4bER6YlBJLys2?= =?utf-8?B?TzRJb1VDREcvbDF1ZVZtREJ3QkNvUnRMSUZPUkxXYUd2cys1dU43cE1tdkwy?= =?utf-8?B?aExCek9ocUhRZHFzWGttUTIxYXZvNnBob084WXBPZXpSZnEvRVhuMG9hRGdJ?= =?utf-8?B?Nm8vY1BORDF3aGtFV2Irem5UOTZFV1BqZUNDMDk0Y1dDUkIrTytFQT09?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: a559a7c1-1dde-41ce-b372-08da3d99eea1 X-MS-Exchange-CrossTenant-AuthSource: VE1PR04MB6560.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 May 2022 15:27:37.0617 (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: EQBUZMek4jmknDaxW8HWGABoQC9NYTv/Aq7f8IsIfMJmoIJOBH1VSSY2VwC7AJS0vkqbOAFLx9LfowC5/FCcOA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM9PR04MB8953 On 24.05.2022 12:50, Roger Pau Monne wrote: > Booting with Shadow Stacks leads to the following assert on a debug > hypervisor: > > Assertion 'local_irq_is_enabled()' failed at arch/x86/smp.c:265 > ----[ Xen-4.17.0-10.24-d x86_64 debug=y Not tainted ]---- > CPU: 0 > RIP: e008:[] flush_area_mask+0x40/0x13e > [...] > Xen call trace: > [] R flush_area_mask+0x40/0x13e > [] F modify_xen_mappings+0xc5/0x958 > [] F arch/x86/alternative.c#_alternative_instructions+0xb7/0xb9 > [] F alternative_branches+0xf/0x12 > [] F __start_xen+0x1ef4/0x2776 > [] F __high_start+0x94/0xa0 > > > This is due to SYS_STATE_smp_boot being set before calling > alternative_branches(), and the flush in modify_xen_mappings() then > using flush_area_all() with interrupts disabled. Note that > alternative_branches() is called before APs are started, so the flush > must be a local one (and indeed the cpumask passed to > flush_area_mask() just contains one CPU). > > Take the opportunity to simplify a bit the logic and intorduce > flush_area_all() as an alias for flush_area_mask(&cpu_online_map...), This is now stale - you don't introduce flush_area_all() here. Sadly nothing is said to justify the addition of a cast there, which - as said before - I think is a little risky (as many casts are), and hence would imo better be avoided. > --- a/xen/arch/x86/smp.c > +++ b/xen/arch/x86/smp.c > @@ -262,7 +262,10 @@ 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_subset(mask, cpumask_of(cpu))); > + /* Exclude use of FLUSH_VCPU_STATE for the local CPU. */ > + ASSERT(!cpumask_test_cpu(cpu, mask) || !(flags & FLUSH_VCPU_STATE)); What about FLUSH_FORCE_IPI? This won't work either with IRQs off, I'm afraid. Or wait - that flag's name doesn't really look to force the use of an IPI, it's still constrained to remote requests. I think this wants mentioning in one of the comments, not the least to also have grep match there then (right now grep output gives the impression as if the flag wasn't consumed anywhere). Jan