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 B4760C00140 for ; Thu, 18 Aug 2022 17:57:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344253AbiHRR5T (ORCPT ); Thu, 18 Aug 2022 13:57:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345140AbiHRR5P (ORCPT ); Thu, 18 Aug 2022 13:57:15 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC05EBC824 for ; Thu, 18 Aug 2022 10:57:13 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id f21so2424927pjt.2 for ; Thu, 18 Aug 2022 10:57:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc; bh=e05CvhD1ZUMfUEn0ZBtVumUZSqrCVNyPhu4vjgJboZk=; b=GwhnujooADK3rszphRziElGJZtVU6I4Xqb2RegMVbHwxkDtnNjHHcO7HvUgubyZ6YE 3DI0cPXr7G9dxjPwO0boNSu9Hl/sHI6xRb+ZH65pXNSdoAAy+XEI0u31PqqqeflFF7Iy Ygy0xx0k4tO1fkUMYX4P9KwhdRwlMwa6mdxXh5V82ap/rr6VZYDcSz5m8Ix0k/2YbUHj 83W7GnqbHg2EPAQVYo+tCZ1LIs19d6V6vqf1mbLQ7LHUAXIbjO+YlTQ34gjLzu8rWx+I ZXfsxvZYUy9tJ2BWM9BH+fJvkk6JYvJtBvaT5qqDmLZCG7QrTBXt4FD+pZJJzpOWMn4x uUkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=e05CvhD1ZUMfUEn0ZBtVumUZSqrCVNyPhu4vjgJboZk=; b=Ilil8QkOdADYBM0vRLXCh4hKe9kMh3mVk9rsC5lH+dyypeaQZtb9g+Ij5ZloAGWxpM glrSxhxDloaeWzuHLioEiibG+IzajgmJ4j4I5ZgjXrVDCvc1rhqxd0yhvj4LKPfk5lLt cByliyn44tUqMJ8KwTkklR2x9CC66qJRv2EJhquHdkdv8FaXmZj78TncFMEpWKC/oGnn UFmxV/O43GjiwecYtdTz7UjkJcRY3QZ1kFJHTSFzOfFnlW639tKLXYu4iKIXzoPnrcLJ WjPKG3FZTypa/oEdiPqtmdZI6PtjDht3YVqdzhc5MnsLQE6f/uk1WGIsiP7zJb7ip1OJ KwlA== X-Gm-Message-State: ACgBeo2vz2Mh4DkeM/UpUkY0fU+J2Yj3Rfxuh7WSI+RDF/sdp8coFnuK B6N5pM4528Yvd2Lzg0oOdyhn4g== X-Google-Smtp-Source: AA6agR75A+8wg2SArLXRaSx/ZSkJUYWTpOGjlEP7zhjOVSUgNBN48pNQJguDQLLN9jD5AyqVgoA7RQ== X-Received: by 2002:a17:902:8b87:b0:16f:1bb7:984a with SMTP id ay7-20020a1709028b8700b0016f1bb7984amr3494576plb.113.1660845433071; Thu, 18 Aug 2022 10:57:13 -0700 (PDT) Received: from google.com (7.104.168.34.bc.googleusercontent.com. [34.168.104.7]) by smtp.gmail.com with ESMTPSA id a7-20020a170902ecc700b0016dbdf7b97bsm1675133plh.266.2022.08.18.10.57.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Aug 2022 10:57:12 -0700 (PDT) Date: Thu, 18 Aug 2022 17:57:09 +0000 From: Sean Christopherson To: Vitaly Kuznetsov Cc: kvm@vger.kernel.org, Paolo Bonzini , Anirudh Rayabharam , Wanpeng Li , Jim Mattson , Maxim Levitsky , Nathan Chancellor , Michael Kelley , linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 03/26] x86/hyperv: Update 'struct hv_enlightened_vmcs' definition Message-ID: References: <20220802160756.339464-1-vkuznets@redhat.com> <20220802160756.339464-4-vkuznets@redhat.com> <875yiptvsc.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <875yiptvsc.fsf@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 18, 2022, Vitaly Kuznetsov wrote: > Sean Christopherson writes: > > > On Tue, Aug 02, 2022, Vitaly Kuznetsov wrote: > >> + * Note: HV_X64_NESTED_EVMCS1_2022_UPDATE is not currently documented in any > >> + * published TLFS version. When the bit is set, nested hypervisor can use > >> + * 'updated' eVMCSv1 specification (perf_global_ctrl, s_cet, ssp, lbr_ctl, > >> + * encls_exiting_bitmap, tsc_multiplier fields which were missing in 2016 > >> + * specification). > >> + */ > >> +#define HV_X64_NESTED_EVMCS1_2022_UPDATE BIT(0) > > > > This bit is now defined[*], but the docs says it's only for perf_global_ctrl. Are > > we expecting an update to the TLFS? > > > > Indicates support for the GuestPerfGlobalCtrl and HostPerfGlobalCtrl fields > > in the enlightened VMCS. > > > > [*] https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/feature-discovery#hypervisor-nested-virtualization-features---0x4000000a > > > > Oh well, better this than nothing. I'll ping the people who told me > about this bit that their description is incomplete. Not that it changes anything, but I'd rather have no documentation. I'd much rather KVM say "this is the undocumented behavior" than "the document behavior is wrong".