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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC8E2C46467 for ; Tue, 3 Jan 2023 17:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237765AbjACRRw (ORCPT ); Tue, 3 Jan 2023 12:17:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238538AbjACRRn (ORCPT ); Tue, 3 Jan 2023 12:17:43 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9674EFD05 for ; Tue, 3 Jan 2023 09:17:40 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id d3so33267846plr.10 for ; Tue, 03 Jan 2023 09:17:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=NmPU0DAPnTo9ly6c5vzl16QReWdT0lifTdN0mL7Hgqw=; b=giqvvDYlfx8gApA/qD/ejkru7bWOWjkxEcyBu+cvH3X6Spcul6ybRNW+zzEhNmxfK0 QEkii7SWMyyjqOmZPhpx5IppYbeon5bwhB6t/JsGlJrULCxBFazNij5TY3lHSuba2eLG zm8kRq2TSFsdWevmf3zFQAyAyRUYq0ayhWyP+4BfxibeqjL7KxnqUxSo1UwcILVG7mni W7KP3Bt0p7dFmKOmZCHxR+ekzmBKWwwobFP2JA/lnOroJkYshMODk5W3+RvatZDNdWZH wiVW+GLM1FqAPFhblnIpf0ohD77BRAjTOVZjQWu8PNmG0H53x9NaW39rKNVLFFa7MxRk swBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=NmPU0DAPnTo9ly6c5vzl16QReWdT0lifTdN0mL7Hgqw=; b=MKazgSuwm3LclWid5EXtn7AwFNLtzF6SL+GT1wynozD0Hfv9niHqYU89kqlO6CkYM1 AmK5vzIqoJY7XUawm9FQOqEbb/gVG4WkldurzTc1Iz8pvDU/3OWIYxFlI78CvAXm/w5J DpbfSoTk7Dka2ug0Zn0t8qXd7IDAWYkjfXj308U2dPvZk5B3Wobh49BN+VfgnY7tfEDM EU6YjnBGuqQA263ZFTvVSPfRV6QJ2vwymNde9v4vUX/NOONCajbIh/5dw9vqq77PyzJY MegS5sn9JObqkftvjYpYHsTlS/F4YT/bCMBeKQ/EPpoy8f22c+XZdlTM5w/inFYw3Ba1 uPwQ== X-Gm-Message-State: AFqh2krXQq0riRReK49Yh7UQ7m2XhGhRtQji2HOOI9sduRPNVar+Q3aQ XlHytNr1ECBkylPMV/h+p4MVcg== X-Google-Smtp-Source: AMrXdXsllXS/A4bjs7uKAjORnXNi/jMIv9YGGiPyRTrSrliuciBf4YnusJr/v4Ip0F9eIeNofiPG8Q== X-Received: by 2002:a17:902:d4d1:b0:189:3a04:4466 with SMTP id o17-20020a170902d4d100b001893a044466mr4251734plg.2.1672766260000; Tue, 03 Jan 2023 09:17:40 -0800 (PST) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id c10-20020a170903234a00b0017f73caf588sm22606911plh.218.2023.01.03.09.17.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Jan 2023 09:17:39 -0800 (PST) Date: Tue, 3 Jan 2023 17:17:35 +0000 From: Sean Christopherson To: Michal Luczaj Cc: pbonzini@redhat.com, dwmw2@infradead.org, kvm@vger.kernel.org, paul@xen.org Subject: Re: [PATCH 1/2] KVM: x86: Fix deadlock in kvm_vm_ioctl_set_msr_filter() Message-ID: References: <20221229211737.138861-1-mhal@rbox.co> <20221229211737.138861-2-mhal@rbox.co> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221229211737.138861-2-mhal@rbox.co> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Dec 29, 2022, Michal Luczaj wrote: > Move synchronize_srcu(&kvm->srcu) out of kvm->lock critical section. This needs a much more descriptive changelog, and an update to Documentation/virt/kvm/locking.rst to define the ordering requirements between kvm->scru and kvm->lock. And IIUC, there is no deadlock in the current code base, so this really should be a prep patch that's sent along with the Xen series[*] that wants to take kvm->-srcu outside of kvm->lock. [*] https://lore.kernel.org/all/20221222203021.1944101-2-mhal@rbox.co