From patchwork Sat Nov 7 01:11:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Masney X-Patchwork-Id: 11888491 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C19F1139F for ; Sat, 7 Nov 2020 01:13:38 +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 7B15D20704 for ; Sat, 7 Nov 2020 01:13:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eVZtrEZw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B15D20704 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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.21226.47528 (Exim 4.92) (envelope-from ) id 1kbClV-0003Bo-G2; Sat, 07 Nov 2020 01:11:37 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 21226.47528; Sat, 07 Nov 2020 01:11:37 +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" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kbClV-0003Bh-Bq; Sat, 07 Nov 2020 01:11:37 +0000 Received: by outflank-mailman (input) for mailman id 21226; Sat, 07 Nov 2020 01:11:35 +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 1kbClT-0003Bc-Sl for xen-devel@lists.xenproject.org; Sat, 07 Nov 2020 01:11:35 +0000 Received: from us-smtp-delivery-124.mimecast.com (unknown [216.205.24.124]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 888e7b8f-2d5a-47e5-9387-8f91592ef49b; Sat, 07 Nov 2020 01:11:34 +0000 (UTC) Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-265-KaIzL_T-O6CZQ9JMKHkH-w-1; Fri, 06 Nov 2020 20:11:32 -0500 Received: by mail-qv1-f70.google.com with SMTP id r11so1776806qvn.1 for ; Fri, 06 Nov 2020 17:11:32 -0800 (PST) Received: from localhost.localdomain (c-98-239-145-235.hsd1.wv.comcast.net. [98.239.145.235]) by smtp.gmail.com with ESMTPSA id q6sm1758584qtq.53.2020.11.06.17.11.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Nov 2020 17:11:30 -0800 (PST) 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 1kbClT-0003Bc-Sl for xen-devel@lists.xenproject.org; Sat, 07 Nov 2020 01:11:35 +0000 X-Inumbo-ID: 888e7b8f-2d5a-47e5-9387-8f91592ef49b Received: from us-smtp-delivery-124.mimecast.com (unknown [216.205.24.124]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id 888e7b8f-2d5a-47e5-9387-8f91592ef49b; Sat, 07 Nov 2020 01:11:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1604711493; 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; bh=s03eFWh3bvVnssKugy+SfcexCfSnOxFiFxui5ZZE6JM=; b=eVZtrEZww1YjvsUVfGezOqx/owmpDb0u9YcL9wkHu1NURBh6wGoInW5APFi6MST0iXrlo1 avpkU/0uXDrRKwGxpFjjEhDMq5xG7HCwiMBsqLuNYVqlRIomOFHtsdLsojUTS2OtgM8qfO YdZeLP6vRoTcEkx3sxtGDxI6PRgF0Do= Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-265-KaIzL_T-O6CZQ9JMKHkH-w-1; Fri, 06 Nov 2020 20:11:32 -0500 X-MC-Unique: KaIzL_T-O6CZQ9JMKHkH-w-1 Received: by mail-qv1-f70.google.com with SMTP id r11so1776806qvn.1 for ; Fri, 06 Nov 2020 17:11:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=s03eFWh3bvVnssKugy+SfcexCfSnOxFiFxui5ZZE6JM=; b=eCHBFn0iN650TG72XnMC/azAUS8rWNsc8+3ulSRNFnCQTbgPbUKGpzbp8gM7FG7/86 lWI5dQOSGp6kzS4jqOUsanbQMOgP9oMYT1FFBK4/v2B2e6sAupTcnAjyUGsMo5qWaiB6 fTbjj4tw+x0q4vcY5evRRsdSrkJrG/kWeQeE0ciwJ/5wHBb60NTvbGMymtoI3uR/4F6S m0z1jmAKOM0rC/jxRfxOrnFtiu4HTcw7wiWCk6qpXDcOEcjwSwiBlPyR8dozBDsOUkuO v9Y7uuAAvi2bt9UioHuFHlZKsXRuD/uCf2RkTZVJW1U7YO9RtFs+su4Dg/6QCxERJCSa UPQw== X-Gm-Message-State: AOAM530QhsOO6OSsZcCL6EtWRtMjGVPy2AXhNtRo5m1B1bCzwswH5LRx J3XElSbWinJUup5dnnjm/LN1Y3JgzEDUYNxYQby+H/2G/j3IraJuTKIMRPjbuB8Oq+SrzA32wqD 8qP4izDKBAfJtBxPGYVlAUCzNdWY= X-Received: by 2002:ac8:51cd:: with SMTP id d13mr270204qtn.148.1604711491826; Fri, 06 Nov 2020 17:11:31 -0800 (PST) X-Google-Smtp-Source: ABdhPJxp4oEucNKi98qPC7sJzn96P9bBblqisJwW0aucCPpUta95o5nBu9m7hEOogL969VFDL1oc3Q== X-Received: by 2002:ac8:51cd:: with SMTP id d13mr270180qtn.148.1604711491516; Fri, 06 Nov 2020 17:11:31 -0800 (PST) Received: from localhost.localdomain (c-98-239-145-235.hsd1.wv.comcast.net. [98.239.145.235]) by smtp.gmail.com with ESMTPSA id q6sm1758584qtq.53.2020.11.06.17.11.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 06 Nov 2020 17:11:30 -0800 (PST) From: Brian Masney To: boris.ostrovsky@oracle.com, jgross@suse.com, sstabellini@kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, dustymabe@redhat.com Subject: [PATCH v2] x86/xen: don't unbind uninitialized lock_kicker_irq Date: Fri, 6 Nov 2020 20:11:19 -0500 Message-Id: <20201107011119.631442-1-bmasney@redhat.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=bmasney@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com When booting a hyperthreaded system with the kernel parameter 'mitigations=auto,nosmt', the following warning occurs: WARNING: CPU: 0 PID: 1 at drivers/xen/events/events_base.c:1112 unbind_from_irqhandler+0x4e/0x60 ... Hardware name: Xen HVM domU, BIOS 4.2.amazon 08/24/2006 ... Call Trace: xen_uninit_lock_cpu+0x28/0x62 xen_hvm_cpu_die+0x21/0x30 takedown_cpu+0x9c/0xe0 ? trace_suspend_resume+0x60/0x60 cpuhp_invoke_callback+0x9a/0x530 _cpu_up+0x11a/0x130 cpu_up+0x7e/0xc0 bringup_nonboot_cpus+0x48/0x50 smp_init+0x26/0x79 kernel_init_freeable+0xea/0x229 ? rest_init+0xaa/0xaa kernel_init+0xa/0x106 ret_from_fork+0x35/0x40 The secondary CPUs are not activated with the nosmt mitigations and only the primary thread on each CPU core is used. In this situation, xen_hvm_smp_prepare_cpus(), and more importantly xen_init_lock_cpu(), is not called, so the lock_kicker_irq is not initialized for the secondary CPUs. Let's fix this by exiting early in xen_uninit_lock_cpu() if the irq is not set to avoid the warning from above for each secondary CPU. Signed-off-by: Brian Masney Reviewed-by: Juergen Gross --- Changes since v1: - Remove duplicate per_cpu() call and pass in irq variable. - Changed subject from 'x86/xen: fix warning when running with nosmt mitigations' - Shorten code comment arch/x86/xen/spinlock.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 799f4eba0a62..043c73dfd2c9 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -93,10 +93,20 @@ void xen_init_lock_cpu(int cpu) void xen_uninit_lock_cpu(int cpu) { + int irq; + if (!xen_pvspin) return; - unbind_from_irqhandler(per_cpu(lock_kicker_irq, cpu), NULL); + /* + * When booting the kernel with 'mitigations=auto,nosmt', the secondary + * CPUs are not activated, and lock_kicker_irq is not initialized. + */ + irq = per_cpu(lock_kicker_irq, cpu); + if (irq == -1) + return; + + unbind_from_irqhandler(irq, NULL); per_cpu(lock_kicker_irq, cpu) = -1; kfree(per_cpu(irq_name, cpu)); per_cpu(irq_name, cpu) = NULL;