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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 D18A0C74A52 for ; Thu, 11 Jul 2019 12:39:20 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 A68102084B for ; Thu, 11 Jul 2019 12:39:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="iFQ5yOQs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A68102084B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jOBhAk7ZCUk27P871jwnDPEHHTdWPQ28kXKjmGsmZe8=; b=iFQ5yOQs7QJETPAK9/cwTV9qU ENWqHoaCZ86VeJRvMd8hjvEBDy/QJFqSHyJczcVWdR6O54tWBuWFl7fHVuwBPZbGRcP4+9eqxaXQN NuChqZgQZXW+H0TouHIztU4hPaEoFSCqx9eNl4xLz5XKFdIvwt2dbwKu+k5DpDfRxvO3lYExR0HkM l9cpCj9jQvatHjop+H4jCOc+cwQcOovVpqZDffJ8WiGn/d1rEaK4jJeJ5iOffwDodiEAFPOpFoHcr 8TggMdxPVo5ySKRDdM10kFPjDkP+CKfEkyJZwVmj0sDycJhUtwHtlufEjcRNEsqmzezCGI9uiJUrA hoYzHBoUQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlYM3-00028A-LG; Thu, 11 Jul 2019 12:39:19 +0000 Received: from szxga06-in.huawei.com ([45.249.212.32] helo=huawei.com) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hlYM0-00027M-TI for linux-arm-kernel@lists.infradead.org; Thu, 11 Jul 2019 12:39:18 +0000 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id D9487673AB83A3D4C26E; Thu, 11 Jul 2019 20:38:59 +0800 (CST) Received: from [127.0.0.1] (10.184.12.158) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.439.0; Thu, 11 Jul 2019 20:38:52 +0800 Subject: Re: [PATCH v3 7/9] arm/arm64: kvm: pmu: Make overflow handler NMI safe To: Julien Thierry , References: <1562596377-33196-1-git-send-email-julien.thierry@arm.com> <1562596377-33196-8-git-send-email-julien.thierry@arm.com> From: Zenghui Yu Message-ID: Date: Thu, 11 Jul 2019 20:38:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:64.0) Gecko/20100101 Thunderbird/64.0 MIME-Version: 1.0 In-Reply-To: <1562596377-33196-8-git-send-email-julien.thierry@arm.com> Content-Language: en-US X-Originating-IP: [10.184.12.158] X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190711_053917_230988_AD95DA02 X-CRM114-Status: UNSURE ( 7.30 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: peterz@infradead.org, jolsa@redhat.com, will.deacon@arm.com, acme@kernel.org, alexander.shishkin@linux.intel.com, mingo@redhat.com, Marc Zyngier , namhyung@kernel.org, liwei391@huawei.com, kvmarm@lists.cs.columbia.edu Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Julien, On 2019/7/8 22:32, Julien Thierry wrote: > When using an NMI for the PMU interrupt, taking any lock migh cause a ^^^^ s/migh/might/ > deadlock. The current PMU overflow handler in KVM takes takes locks when ^^^^^ ^^^^^ two "takes" ? Thanks, zenghui > trying to wake up a vcpu. > > When overflow handler is called by an NMI, defer the vcpu waking in an > irq_work queue. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel