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=-2.2 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 ABB60C76191 for ; Thu, 18 Jul 2019 13:18:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8CD8A21841 for ; Thu, 18 Jul 2019 13:18:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390385AbfGRNSz (ORCPT ); Thu, 18 Jul 2019 09:18:55 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:45477 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726735AbfGRNSy (ORCPT ); Thu, 18 Jul 2019 09:18:54 -0400 Received: by mail-wr1-f65.google.com with SMTP id f9so28634764wre.12 for ; Thu, 18 Jul 2019 06:18:53 -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=mEVAjfkq7OMpRBKdhALaEN7JTbLll/ByQWI1BOsbqL8=; b=fTw6mqGWVW96n5pJ8dbP4DjHy7+TsI++yQNl8C139MFnruwNUv7vN44+ImuL1OY4OZ HhnI93h7AI/eieLGXgQovoYZ9Irx0mm0tozA7zVAaU9tXtsaS/y9+/hdahoCb3njTbed fZAr/8fsNyAYW7UzIXnSqZdeEpIepSbKHgKy4HPJP5+HxtkktRtj0jL2+RMz2PMQvtdL TAoBBFvY5FSVfx9TebZLqKPbtYLqd0gMAYdyBZ6C5jKUQzUTaIXd7U1eKmRV3mphse5M 9IxUfEGwgjudLEnN9KRAg3CweamSZBjjiD+4Yk0TaDiRjKcRdkvg08n+Y+WCuDhC5j/r NaYw== X-Gm-Message-State: APjAAAUdnD7ye/41FbioS+J19rUP/vI4CMQXAA6bJPnX5J2Q4lJrobxX vCd+ePKLa86eUjyOXkQz3R3xpw== X-Google-Smtp-Source: APXvYqym+1/Te37GQsHiaf/NBjXwzk5+HxsedDWH52Azhd+jZ+GsMFR5zgvGB1TuWVoWqrSqFp9R5g== X-Received: by 2002:adf:dd03:: with SMTP id a3mr2105031wrm.87.1563455932572; Thu, 18 Jul 2019 06:18:52 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:e427:3beb:1110:dda2? ([2001:b07:6468:f312:e427:3beb:1110:dda2]) by smtp.gmail.com with ESMTPSA id x20sm21036282wmc.1.2019.07.18.06.18.51 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Thu, 18 Jul 2019 06:18:51 -0700 (PDT) Subject: Re: [PATCH v2 04/22] x86/kvm: Don't call kvm_spurious_fault() from .fixup To: Sean Christopherson Cc: Josh Poimboeuf , x86@kernel.org, linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Nick Desaulniers , Arnd Bergmann , Jann Horn , Randy Dunlap , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= References: <64a9b64d127e87b6920a97afde8e96ea76f6524e.1563413318.git.jpoimboe@redhat.com> <65bbf58d-f88b-c7d6-523b-6e35f4972bf2@redhat.com> <20190718131654.GE28096@linux.intel.com> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: <1b891612-18e6-48ed-cfb5-05e8aca79dcb@redhat.com> Date: Thu, 18 Jul 2019 15:18:50 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190718131654.GE28096@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 18/07/19 15:16, Sean Christopherson wrote: >> Acked-by: Paolo Bonzini >> >> This has a side effect of adding a jump in a generally hot path, but >> let's hope that the speculation gods for once help us. > Any reason not to take the same approach as vmx_vmenter() and ud2 directly > from fixup? I've never found kvm_spurious_fault() to be all that helpful, > IMO it's a win win. :-) Honestly I've never seen a backtrace from here but I would rather not regret this when a customer encounters it... Paolo