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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 CF25BC4727F for ; Fri, 25 Sep 2020 17:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80E0221D42 for ; Fri, 25 Sep 2020 17:31:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DllsNc6L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729650AbgIYRbT (ORCPT ); Fri, 25 Sep 2020 13:31:19 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33345 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727751AbgIYRbS (ORCPT ); Fri, 25 Sep 2020 13:31:18 -0400 Dkim-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601055077; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kgoDrp/Imua9rkBntWaYSIW0+QvG7ttl6BenhB/EUzM=; b=DllsNc6LB5mJF5GUh5DZwu8TVa4oVZg7QkgkKhHtEfj4BZHUurVgEKSs+oI8zEp1aLtdc3 Ffy4ukbUNKgp9H0vdJSg4ZdJ/P5EoJih7RkoT4O6Y6VIrkX64jVOolXCjtgn7Wykelr3WL kpT4OLjyC8bE57Liogt+Hciy1pIHSpk= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-249-DoNGsHt_NxyWwUb37TYi9A-1; Fri, 25 Sep 2020 13:31:15 -0400 X-MC-Unique: DoNGsHt_NxyWwUb37TYi9A-1 Received: by mail-wr1-f69.google.com with SMTP id d13so1318209wrr.23 for ; Fri, 25 Sep 2020 10:31:14 -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:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=kgoDrp/Imua9rkBntWaYSIW0+QvG7ttl6BenhB/EUzM=; b=BALe3Ob0f7ExkYWDSXbcCwxUlLhGqrEgVNMAe3CvWt9MuuvYhZ+DwxdFT2WeOSRjNY 5WF5l0LCk/VFrbTi92s1z/yoBtlA3YPQNtoq+PtLwyyDl0/j3TIOMqCYGfh4cobBWcUU lqybHICDgTmfKwB8RkVAFAViYToBlIHKzHs7ze/ZMwsO6zvEuCWrN0wQ0FjNecnNMvzF zo3KKkso6m8ZKiiHbAc6liXRHakIkT2gLL/2oS994ZzP0lN6fe/ttCu91zKUMVUHSSil BJ5P64K7aSPWmVeaLu916nJCXSNvyrIWYty/LkVvqyq2tnpm9SvA0kq65PqGnDd/yLb1 CbXQ== X-Gm-Message-State: AOAM530l5etwvyX3U4sn6KURw6ZvIgMMSX3Q7OmZJexfTedaGKUdj66B wr4w4Fh1z6SaqARd8AVtUZiTyi+/FqslVXK+7B7b2mD1MK/ralXo4AdVLzUNjZrfwS8RARRFCGC xkn4+zYURBHRuzw4w0TnaYKyA X-Received: by 2002:a1c:4c0d:: with SMTP id z13mr4020260wmf.113.1601055073294; Fri, 25 Sep 2020 10:31:13 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzPTDkbJwYC2USu6HcpR/XlLvGZo9MtasrQB1dk8DmaTxAl37UdJ+X+8ppmKhjjYed/hBPwxQ== X-Received: by 2002:a1c:4c0d:: with SMTP id z13mr4020240wmf.113.1601055073075; Fri, 25 Sep 2020 10:31:13 -0700 (PDT) Received: from ?IPv6:2001:b07:6468:f312:ec9b:111a:97e3:4baf? ([2001:b07:6468:f312:ec9b:111a:97e3:4baf]) by smtp.gmail.com with ESMTPSA id p11sm3389322wma.11.2020.09.25.10.31.11 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 25 Sep 2020 10:31:12 -0700 (PDT) Subject: Re: [PATCH v2 0/2] INVD intercept change to skip instruction To: Jim Mattson , Tom Lendacky Cc: kvm list , the arch/x86 maintainers , LKML , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Joerg Roedel , Brijesh Singh , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" References: From: Paolo Bonzini Message-ID: Date: Fri, 25 Sep 2020 19:31:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/09/20 23:20, Jim Mattson wrote: > On Thu, Sep 24, 2020 at 11:42 AM Tom Lendacky wrote: >> >> From: Tom Lendacky >> >> This series updates the INVD intercept support for both SVM and VMX to >> skip the instruction rather than emulating it, since emulation of this >> instruction is just a NOP. > > Isn't INVD a serializing instruction, whereas NOP isn't? IIRC, Intel > doesn't architect VM-entry or VM-exit as serializing, though they > probably are in practice. I'm not sure what AMD's stance on this is. Of course that isn't changed by this patch, though. Queuing both, but a clarification would be useful. The same applies even to CPUID. Paolo