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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 928B2C433FF for ; Tue, 13 Aug 2019 09:06:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 733A720679 for ; Tue, 13 Aug 2019 09:06:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727227AbfHMJGz (ORCPT ); Tue, 13 Aug 2019 05:06:55 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:33175 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726827AbfHMJGz (ORCPT ); Tue, 13 Aug 2019 05:06:55 -0400 Received: by mail-wr1-f68.google.com with SMTP id n9so107144633wru.0 for ; Tue, 13 Aug 2019 02:06:54 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:openpgp:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=MRboZnkOwIqMqx46t0ZQ9zepiSGdc691QK9w7wR1ygw=; b=ULcch2o/X9bj+6VxnBJkkJoSwXaeugaS/qHrca8v8C6TFdzNS/iYS4aqr4cNhdILrn p7N2qVQSidoylYotvJY9B+HrUkLqDUC0hHNIrzW6ADE7OqD5YHJ/9JkbFC/s45xrC9Gu fKIpiaesg23I3UWsT0NpJo6eo2Llj4j+IuxQTw/haJ+iaZFlCGRcPUvpQihdst1di6+T JaZTbWCO70D/Q35wBEZ1VtS/uglBH8YVULrhRt0tVQZO08aXTiI9PcRc+IhbW4WEpfHt 8Pkk4k2qfhMqjbSzes3XmMJj5oXJ/wUCe4RZr11AKRGgAstxpu1Je+GUJreDm/be2HtL Ga+A== X-Gm-Message-State: APjAAAXSaqTBFfjYR188PgzhNC7AULY1JB6wvfJWIdTIcyiObU8xZYlR BHdlsxS5eCa0mapFO8323v1aoQ== X-Google-Smtp-Source: APXvYqweK6uM1R3qYisV+zwsl38ikaVzEXE80NEPe0UggCtqMVhBk6tbs9HWluPuTVYiwrckbrYbsA== X-Received: by 2002:adf:aa8d:: with SMTP id h13mr39037899wrc.307.1565687213313; Tue, 13 Aug 2019 02:06:53 -0700 (PDT) Received: from [192.168.10.150] ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id a17sm677722wmm.47.2019.08.13.02.06.51 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Tue, 13 Aug 2019 02:06:52 -0700 (PDT) Subject: Re: [RFC PATCH v6 27/92] kvm: introspection: use page track To: =?UTF-8?Q?Adalbert_Laz=c4=83r?= , kvm@vger.kernel.org Cc: linux-mm@kvack.org, virtualization@lists.linux-foundation.org, =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= , Konrad Rzeszutek Wilk , Tamas K Lengyel , Mathieu Tarral , =?UTF-8?Q?Samuel_Laur=c3=a9n?= , Patrick Colp , Jan Kiszka , Stefan Hajnoczi , Weijiang Yang , Yu C Zhang , =?UTF-8?Q?Mihai_Don=c8=9bu?= , =?UTF-8?B?TmljdciZb3IgQ8OuyJt1?= , Marian Rotariu References: <20190809160047.8319-1-alazar@bitdefender.com> <20190809160047.8319-28-alazar@bitdefender.com> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: <0e6703cd-2d0b-ccd2-c353-c5f5de659837@redhat.com> Date: Tue, 13 Aug 2019 11:06:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190809160047.8319-28-alazar@bitdefender.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 09/08/19 17:59, Adalbert Lazăr wrote: > + > + /* > + * This function uses kvm->mmu_lock so it's not allowed to be > + * called under kvmi_put(). It can reach a deadlock if called > + * from kvm_mmu_load -> kvmi_tracked_gfn -> kvmi_put. > + */ > + kvmi_clear_mem_access(kvm); kvmi_tracked_gfn does not exist yet. More in general, this comment says why you are calling this here, but it says nothing about the split of responsibility between kvmi_end_introspection and kvmi_release. Please add a comment for this as soon as you add kvmi_end_introspection (which according to my earlier review should be patch 1). Paolo