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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C170DC47080 for ; Tue, 1 Jun 2021 23:13:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A1C686124B for ; Tue, 1 Jun 2021 23:13:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235040AbhFAXPb (ORCPT ); Tue, 1 Jun 2021 19:15:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59584 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234989AbhFAXPb (ORCPT ); Tue, 1 Jun 2021 19:15:31 -0400 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DD60C061574; Tue, 1 Jun 2021 16:13:48 -0700 (PDT) Received: by mail-ej1-x629.google.com with SMTP id l1so939676ejb.6; Tue, 01 Jun 2021 16:13:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=zh1+/6WfqdVuCg7ID+TQV9ppVnJ4x/cqO6OMVZxi09Q=; b=ovTam58e4mYWAmOtX8O9o9KMOV3qEYdvXzOTKSuqXqvtnbYh63J5II9hnT/u/13ODS SRX9mMyD7BdpIGRRxgZz6jdZFfv47vOM42jTscBuBlGkr9G+4kJWMSb0+AGDchOxQRYr 8WDaYTIaofSKBBgNNRRQScDTtWwllbH4DTcC/5+KYQ5Cie47fSA0nnp99dhYCpTVWD78 BQpKD5Xv6pBVHhCfmRkhr8Jt4yEGlD8VItQChC6WfLn+tF6SaRo25RWGcACAGN8CaJ9z MZ3JT1rdZsMt28zGCaiYte/8w/BO/mYd3TXh/E44OqtWP+ROcqu/rb9kd9uEFVazsjAv 1A2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=zh1+/6WfqdVuCg7ID+TQV9ppVnJ4x/cqO6OMVZxi09Q=; b=H1XKGjRMvk3G/+ySrvX6u0KGiwnN6HYY84AIsdF//27sqT7/Df69vPy626eGsvNp3G As3wywuwYb0pucpv4DFjkoLjQW164ulCbeIEHbPTI4SDjHA8TeUJvvOhN08WuSGFLXNX WMrHBmsBwsi+3S/DNOc5Al+DZ8bLPRPqeEj5L5og/ezDASvAmZTAGPJStuzlai/B2D8v npscZxsil4S9GAxl3NgC9gigK2wzYjt4QTFI235Jmilwt7G+d7GT1lH5lTKd1vaGXHP9 qnBjLxR04PX4OuKbu+OA+Kwi0TxbFn4er4GSGGKUDqnk9IFqiY0mQOWoAS20AubUceQs 7Fbw== X-Gm-Message-State: AOAM533EuWPwjyQbg1r116he+vgtisOmYFZm25YixYSc3W8yc14wL/+9 4qis4uKXdHVQeOgASqEaeRI= X-Google-Smtp-Source: ABdhPJyJZZiHu8zdJIZVwUwAJhA75O5Pcldzt4kz1cEG7CswolwKOoxougSP2vOlPjwCEKx5+Qk10w== X-Received: by 2002:a17:906:2ec6:: with SMTP id s6mr30948371eji.65.1622589226849; Tue, 01 Jun 2021 16:13:46 -0700 (PDT) Received: from anparri (host-95-246-186-31.retail.telecomitalia.it. [95.246.186.31]) by smtp.gmail.com with ESMTPSA id m16sm236824edq.56.2021.06.01.16.13.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Jun 2021 16:13:46 -0700 (PDT) Date: Wed, 2 Jun 2021 01:13:39 +0200 From: Andrea Parri To: Long Li Cc: Michael Kelley , "longli@linuxonhyperv.com" , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , Wei Liu , Lorenzo Pieralisi , Rob Herring , Bjorn Helgaas , "linux-hyperv@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Andrea Parri Subject: Re: [PATCH] PCI: hv: Move completion variable from stack to heap in hv_compose_msi_msg() Message-ID: <20210601231339.GA1391@anparri> References: <1620806824-31151-1-git-send-email-longli@linuxonhyperv.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org > I agree if the intent is to deal with a untrusted host, I can follow the same principle to add this support to all requests to VSP. But this is a different problem to what this patch intends to address. I can see they may share the same design principle and common code. My question on a untrusted host is: If a host is untrusted and is misbehaving on purpose, what's the point of keep the VM running and not crashing the PCI driver? I think the principle can be summarized with "keep the VM _running, if you can handle the misbehaviour (possibly, warning on "something wrong/unexpected just happened"); crash, otherwise". Of course, this is just a principle: the exact meaning of that 'handle' should be leverage case by case (which I admittedly haven't here); I'm thinking, e.g., at corresponding complexity/performance impacts and risks of 'mis-assessments'. Thanks, Andrea