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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 D2A43C433B4 for ; Mon, 12 Apr 2021 18:34:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B78E61206 for ; Mon, 12 Apr 2021 18:34:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245054AbhDLSfG (ORCPT ); Mon, 12 Apr 2021 14:35:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237110AbhDLSfE (ORCPT ); Mon, 12 Apr 2021 14:35:04 -0400 Received: from mail-oi1-x22a.google.com (mail-oi1-x22a.google.com [IPv6:2607:f8b0:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 580E2C06174A for ; Mon, 12 Apr 2021 11:34:46 -0700 (PDT) Received: by mail-oi1-x22a.google.com with SMTP id i3so14397999oik.7 for ; Mon, 12 Apr 2021 11:34:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=B0snQNysZJ+eshswUbAATX3408PkT3sHTGisEmQRaBI=; b=IsdBy7Y/xmB8myrYlMcMiSwKQpCyqozNO016+uuiDGDNmjEQMQMtKQT1O+LeOkXvse J5dsvtTfRBQmpe1/98/Xr8lUlqaVQmFb3UTBov6DVfgEzz/Q+K5SscVQ0eYGManVVXz6 7sa1XVPKwXBqF3rrdjoM68UcJ2BRZhds2SSqmeN1EZqjs9JHC6hCQ8dYalP9U5U0CDAo OdAZAi3C5IdcRVzjPg1oVHfDbUXyvNlPUYb4QbD036RCNftz6pTpjwGtQYag1mkJuniH 5Pc4tjVgYjo6C7XSFUbsv/wm+clXa5+a8uXiKTOvSgRj5uY6jvHvcXD31msbwYm+a1ZU r1TQ== 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=B0snQNysZJ+eshswUbAATX3408PkT3sHTGisEmQRaBI=; b=U3qWg+ju/EAisSUMbS5h5jCzJn0WdXBT2SHrBPtqYgREBZPp5WVxgOFczMazsLXnZb llwcZzOkdEsx5MrZT1clGCuIOenBea2cf2sklHK7t5xWgc6hPTQcsTBrJUL/PoEoAPSR KZlP5kInmbMbWXt0Dgp8wfgubY/tbh+LHrngvzx8ZHjoeCJZ+st/6YxYFrdspH/0174G ReVzqVPsXR9fl9odFUK44zevn1CFAySKOvJclSqwyE3d09/lxn0b9EPEA+Nj9DMwkNcX Iw7aJPPz7RwSlmw5x0MiZ/TjgpZty5GmRwmDEEYhwMpMmUdX5qgXOZRj0hwKaJSH3T0C JOdg== X-Gm-Message-State: AOAM530lA/ymQZaHtRLSPtZfpCppJAc4HFm8nq5atQpuMO4k4nzbB6K9 52eGnw2vCttH73U8+now+W0WM+gta1OC1RZaI20vCQ== X-Google-Smtp-Source: ABdhPJzbTsNFNsgJCq0R6sPG/+Uw4Bcv0ply156WXPYUJEkjjlz7V73QxyWbH2frTyfzaD1/yzUR9lYn2tuwb237SyU= X-Received: by 2002:a05:6808:f14:: with SMTP id m20mr397142oiw.13.1618252485403; Mon, 12 Apr 2021 11:34:45 -0700 (PDT) MIME-Version: 1.0 References: <20210412130938.68178-1-david.edmondson@oracle.com> In-Reply-To: <20210412130938.68178-1-david.edmondson@oracle.com> From: Jim Mattson Date: Mon, 12 Apr 2021 11:34:33 -0700 Message-ID: Subject: Re: [PATCH 0/6] KVM: x86: Make the cause of instruction emulation available to user-space To: David Edmondson Cc: LKML , kvm list , Paolo Bonzini , Vitaly Kuznetsov , "H. Peter Anvin" , "the arch/x86 maintainers" , Sean Christopherson , Thomas Gleixner , Joerg Roedel , Wanpeng Li , Borislav Petkov , Ingo Molnar , Aaron Lewis Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 12, 2021 at 6:09 AM David Edmondson wrote: > > Instruction emulation happens for a variety of reasons, yet on error > we have no idea exactly what triggered it. Add a cause of emulation to > the various originators and pass it upstream when emulation fails. What is userspace going to do with this information? It's hard to say whether or not this is the right ABI without more context.