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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E6530C433EF for ; Thu, 30 Jun 2022 07:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232956AbiF3Hgt (ORCPT ); Thu, 30 Jun 2022 03:36:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232787AbiF3Hgs (ORCPT ); Thu, 30 Jun 2022 03:36:48 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 808191A81B for ; Thu, 30 Jun 2022 00:36:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656574606; 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: in-reply-to:in-reply-to:references:references; bh=PwzmZMvr1HwTOyfvLBeay0UNdb3hWyqojFY1Kj6edFc=; b=ToLNUmgJkq8DzTOgsn0F6CyBXO4GhnET3xsVFjXZzQITrVKdYUi+TGzvweqtV3j8d+7ndq PKk2qa7xTXfc1H5rWhgAGZBiXqQbv/Y4udEHncOAXN13bZRLyxsy4AKeABGb0ZTJwxNsmy QFVmsklU26EQ8hLT1I+tX/WkmjY+mHo= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-660-tsqQ2h_9P6CyofEkBYS0nA-1; Thu, 30 Jun 2022 03:36:42 -0400 X-MC-Unique: tsqQ2h_9P6CyofEkBYS0nA-1 Received: by mail-wm1-f72.google.com with SMTP id e24-20020a05600c219800b003a0471b1904so1030821wme.1 for ; Thu, 30 Jun 2022 00:36:42 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=PwzmZMvr1HwTOyfvLBeay0UNdb3hWyqojFY1Kj6edFc=; b=Mi1g8+ChmtSGoDB2us/Ubfi01Or+ino2l7AKgR7gyLj8qhRpOJcZcdCq48aUMK2lwG gQ0az0N09XGJ/QtiFqp3qIJFd3A0kV/AgfvKg6pku9bjUnh0ubCscuCKlCgZWDjT1PlE Ax+1KASJjeh5Y6Yp9JNLTxBk/kV+KZHTbtr1vAEGDzxBOYnju2l1XsI9FfXbg+67iOfP fcVWUi7ZtakWF0Ex+0rCxsJDgA75nCT4kLE+biZrkzR8JctmLeonLSWXZSbMOuQ4IWjK n1OH0QplheIobA0nkKJ/F9wB4S0ZAK7if66EJx9Tkb1WrrzyTRVKCphE6/yj4Rms4eT7 EqfQ== X-Gm-Message-State: AJIora9HRlVcGEe3MwMSP57eQvj3SAAzLSAKmQG9GdeBLQf9O+2f2HOa WrILJL01nhVzVWcCI8FWEowI51s0lX1l3xOh+rCj41vnuhA/liIkIe3t/vdhRq4R/tN9T0kJFeR FY8AaBSEQG1i6wwSQ3CKMUjbhYqFZO3LHteM+s0tjFUlg6A1b6FRrke2kugdETqp/xz0lZ6yBPK Ds X-Received: by 2002:a5d:6704:0:b0:21b:8258:b773 with SMTP id o4-20020a5d6704000000b0021b8258b773mr6600904wru.284.1656574601153; Thu, 30 Jun 2022 00:36:41 -0700 (PDT) X-Google-Smtp-Source: AGRyM1vE3BOs0DEpp+YFr2cGu7j4qggJVT3ycC/Awg1J1DjBCXCJeDvJEASklLYOzQTIogJGAkKlxA== X-Received: by 2002:a5d:6704:0:b0:21b:8258:b773 with SMTP id o4-20020a5d6704000000b0021b8258b773mr6600874wru.284.1656574600876; Thu, 30 Jun 2022 00:36:40 -0700 (PDT) Received: from fedora (nat-2.ign.cz. [91.219.240.2]) by smtp.gmail.com with ESMTPSA id f20-20020a05600c155400b0039c41686421sm1868636wmg.17.2022.06.30.00.36.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Jun 2022 00:36:40 -0700 (PDT) From: Vitaly Kuznetsov To: Jim Mattson Cc: kvm@vger.kernel.org, Paolo Bonzini , Sean Christopherson , Anirudh Rayabharam , Wanpeng Li , Maxim Levitsky , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 28/28] KVM: nVMX: Use cached host MSR_IA32_VMX_MISC value for setting up nested MSR In-Reply-To: References: <20220629150625.238286-1-vkuznets@redhat.com> <20220629150625.238286-29-vkuznets@redhat.com> Date: Thu, 30 Jun 2022 09:36:39 +0200 Message-ID: <87tu82siuw.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jim Mattson writes: > On Wed, Jun 29, 2022 at 8:07 AM Vitaly Kuznetsov wrote: >> >> vmcs_config has cased host MSR_IA32_VMX_MISC value, use it for setting >> up nested MSR_IA32_VMX_MISC in nested_vmx_setup_ctls_msrs() and avoid the >> redundant rdmsr(). >> >> No (real) functional change intended. > > Just imaginary functional change? :-) > Well, yea) The assumption here is that MSR_IA32_VMX_MISC's value doesn't change underneath KVM, caching doesn't change anything then. It is, of course, possible that when KVM runs as a nested hypervisor on top of something else, it will observe different values. I truly hope this is purely imaginary :-) >> >> Signed-off-by: Vitaly Kuznetsov > Reviewed-by: Jim Mattson > Thanks! -- Vitaly