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 1BA8DC433EF for ; Wed, 15 Jun 2022 09:01:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243896AbiFOJBl (ORCPT ); Wed, 15 Jun 2022 05:01:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233619AbiFOJBi (ORCPT ); Wed, 15 Jun 2022 05:01:38 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 355E73466B; Wed, 15 Jun 2022 02:01:37 -0700 (PDT) Received: from anrayabh-desk (unknown [167.220.238.193]) by linux.microsoft.com (Postfix) with ESMTPSA id 3867620C3230; Wed, 15 Jun 2022 02:01:30 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 3867620C3230 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1655283696; bh=Fo6CSnNJRE/YjGZUQshS1lDdeF7gEOjNbUYnU0G63RU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OnaD1ScM3O1zqniZALodPx0ED0jG6QR1ED06vK40uwFVVy0zVtA2Puo7eTETNo7lJ A2oCRhDaQpc8Y3RfIwyP9K6GrmtQxmU42b9laE3IGw37KnsfnuzeuCBT/YYcIxBn8L oe7BZvT7sHS7+mYNYukqkWqJ/xdjW3323GG9QdNQ= Date: Wed, 15 Jun 2022 14:31:25 +0530 From: Anirudh Rayabharam To: Paolo Bonzini Cc: Vitaly Kuznetsov , mail@anirudhrb.com, kumarpraveen@linux.microsoft.com, wei.liu@kernel.org, robert.bradford@intel.com, liuwe@microsoft.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Ilias Stamatis , Maxim Levitsky , Sean Christopherson Subject: Re: [PATCH] KVM: nVMX: Don't expose TSC scaling to L1 when on Hyper-V Message-ID: References: <20220613161611.3567556-1-anrayabh@linux.microsoft.com> <87sfo7igis.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Jun 14, 2022 at 07:20:34PM +0200, Paolo Bonzini wrote: > On 6/14/22 14:19, Vitaly Kuznetsov wrote: > > The latest version: > > https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/tlfs/datatypes/hv_vmx_enlightened_vmcs > > > > has it, actually. It was missing before (compare with e.g. 6.0b version > > here: > > https://github.com/MicrosoftDocs/Virtualization-Documentation/raw/live/tlfs/Hypervisor%20Top%20Level%20Functional%20Specification%20v6.0b.pdf) > > > > but AFAIR TSC scaling wasn't advertised by genuine Hyper-V either. > > Interestingly enough, eVMCS version didn't change when these fields were > > added, it is still '1'. > > > > I even have a patch in my stash (attached). I didn't send it out because > > it wasn't properly tested with different Hyper-V versions. > > > > -- Vitaly > > Anirudh, can you check if Vitaly's patches work for you? I will check it. But I wonder if they fit the criteria for inclusion in stable trees... It is important for the fix to land in the stable trees since this issue is a regression that was introduced _after_ 5.13. (I probably should've mentioned this in the changelog.) Thanks, Anirudh. > > Paolo