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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 87E03C433DF for ; Tue, 30 Jun 2020 00:16:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5FB9F20780 for ; Tue, 30 Jun 2020 00:16:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jfVVGor5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728454AbgF3AQy (ORCPT ); Mon, 29 Jun 2020 20:16:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726182AbgF3AQx (ORCPT ); Mon, 29 Jun 2020 20:16:53 -0400 Received: from mail-ot1-x342.google.com (mail-ot1-x342.google.com [IPv6:2607:f8b0:4864:20::342]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88652C061755; Mon, 29 Jun 2020 17:16:53 -0700 (PDT) Received: by mail-ot1-x342.google.com with SMTP id d4so17078257otk.2; Mon, 29 Jun 2020 17:16:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=LoJkbpQEJ/7kCO6soZpUK1Fa5w/uxhfe+XsMfi/wXsQ=; b=jfVVGor58svmAJpb85NgXWFPb5MaixA2/7PkoZdjOj6f5B2n7gGjn6DIaEbqH9ZJfI EcUnwGt44Gx4SV8jfKsvI/6doC62Jsy3wTjtBDQr6DT+bLo8uNl3fVIwUi4yfTBYuLps ezPQJl3O3l3hFBLmrzUArQRN2ERqk/j5L5U2FHQi47J4WzwlFuQd83ljeJtNoJ1j92BB lPs1nBDbqtkWsAIeasT6opLz/859jdQlPTjNVn31VpFEt7NxqEDl7ZV1A0RdfL/j6577 incT8JWZeTJXDKnin3D7ZDTjwj4Pcwm06p3jNIwibXz3XeV/HcLfIbqKU5Ak01YxUfyQ SHAQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=LoJkbpQEJ/7kCO6soZpUK1Fa5w/uxhfe+XsMfi/wXsQ=; b=pkjaBvGw0V94PeWVj3B8Lulm5Wk9P3Zs7AMM0AfQ0cWIOc4PMI3JszIaa6YX/momKm 9L8ZNL3MZqrL/R64LssZeuJXLaRbq9gyZei7dIPsgv3nz6g8UVcyr6E2PYqf+lyAdPbk tKhNZ+94DNE/MY9AUkl7gTzuVcB/dKWKaa23KTMjeUrRmkCx41zHsnIr4j2ysh6E6stV U82rneXp5ucUVGepxwieAUyM4MBrTD7mgs6ZffrKs0ODRvJZRJEGAUm2WSf3FGST58s5 PDC+a09m6T/bsBF64IBQ77AnR3SPFNvRmoGc9z7LdaAJoxlfW6J+1/sriQ6gxDDM6Jmq 3Ehg== X-Gm-Message-State: AOAM530BpC0UhCoF1QO3nOUYT21phrhciUt/ooRG6yJqRzPyjMOWSpsr zO+0bzGzSak3TURJwWKUTogsiuBvQabalUTb5x4= X-Google-Smtp-Source: ABdhPJzut6Wv9skBg3QezX/53wVPagQKY5Ns5iTn5U3lYHn/XtINnqa4uHw4jLNddFgFwnA3qm9MPJ8lSU/lHeCJHjg= X-Received: by 2002:a9d:5a92:: with SMTP id w18mr6081413oth.56.1593476212981; Mon, 29 Jun 2020 17:16:52 -0700 (PDT) MIME-Version: 1.0 References: <1593426391-8231-1-git-send-email-wanpengli@tencent.com> <877dvqc7cs.fsf@vitty.brq.redhat.com> <20200629154212.GC12312@linux.intel.com> In-Reply-To: <20200629154212.GC12312@linux.intel.com> From: Wanpeng Li Date: Tue, 30 Jun 2020 08:16:41 +0800 Message-ID: Subject: Re: [PATCH] KVM: X86: Fix async pf caused null-ptr-deref To: Sean Christopherson Cc: Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Vivek Goyal , LKML , kvm Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 29 Jun 2020 at 23:42, Sean Christopherson wrote: > > On Mon, Jun 29, 2020 at 03:59:25PM +0200, Paolo Bonzini wrote: > > On 29/06/20 15:46, Vitaly Kuznetsov wrote: > > >> + if (!lapic_in_kernel(vcpu)) > > >> + return 1; > > >> + > > > I'm not sure how much we care about !lapic_in_kernel() case but this > > > change should be accompanied with userspace changes to not expose > > > KVM_FEATURE_ASYNC_PF_INT or how would the guest know that writing a > > > legitimate value will result in #GP? > > > > Almost any pv feature is broken with QEMU if kernel_irqchip=off. I > > wouldn't bother and I am seriously thinking of dropping all support for > > that, including: > > Heh, based on my limited testing, that could be "Almost everything is > broken with Qemu if kernel_irqchip=off". It is broken for several years. :)