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=-7.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6EF49C07E9C for ; Tue, 6 Jul 2021 21:20:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5AD7861CAC for ; Tue, 6 Jul 2021 21:20:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230032AbhGFVWm (ORCPT ); Tue, 6 Jul 2021 17:22:42 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25276 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229770AbhGFVWl (ORCPT ); Tue, 6 Jul 2021 17:22:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1625606401; 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=dmeFiaZKysTgf+CZ3J794gocPBdvCL0/vBhDrnYH448=; b=Qn1H3xRwzPNV0r6tMEwWEUuxkWCJ6hCSq2Ee2XvER7xr/FCVik/PVJZctJtmcmlL+3V5TE 8o3ujJJKnkzzq18N/pXY6+ruLnulKBiSt7O1tocX+ELfl/OO0ObkPQ93h6FigmK0AzmwXh 4KArJy50sFdMiFeAFeztfv6rvYvYe2E= Received: from mail-lf1-f72.google.com (mail-lf1-f72.google.com [209.85.167.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-211-zjW6gtIsN06v72h8widhKg-1; Tue, 06 Jul 2021 17:20:00 -0400 X-MC-Unique: zjW6gtIsN06v72h8widhKg-1 Received: by mail-lf1-f72.google.com with SMTP id i12-20020ac25b4c0000b02903478da4c94bso33454lfp.13 for ; Tue, 06 Jul 2021 14:20:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=dmeFiaZKysTgf+CZ3J794gocPBdvCL0/vBhDrnYH448=; b=ZUbCjqTi/UoGPiTEFdpjo6HpwZHjd5pUWLfpyPI/89+ty7QF2vk6lNe8QhjmnMsM2L bpdlTq3aq5f88jycviyJbKgdsmba6CqeVTBpj0gHvZzxOpUqI6vwOdB4FISEsZ6aW6G+ 3gCIQxmv35P+DiNk6k5RYpcyVOO9pi/fjoHUzivgHMYswaBxHxYa5MAwxnWnGPTcbx/n X/T8s6oHh2kjVAdTlKWpphvUWD1UFUHDyUlSUSw40sTjreqrgobMS2VBqP9Go2YRJcK7 kLoZTSah/2o8VRsUKSXw54JM+Kaiuan0rWgyOufUkDTOX0YcSMcd9ArWKGE26IOCY+8e 3d8w== X-Gm-Message-State: AOAM532SPckTslS1ckRvecm+EMtTUGJ3d3B7SEUIZWILJLWYThVoBpLr tgJAVjCrP2yITFKhj4/N8MIx22NS/88P2Q702PzhZE2DlhebBRtl/H7uoCjQ1vIi//4lmyoVLqG gCXRawgNUld4QxmN0Iq2sL3Dgqmj5QAGYWfGaqZq2 X-Received: by 2002:a2e:824e:: with SMTP id j14mr16683953ljh.445.1625606398834; Tue, 06 Jul 2021 14:19:58 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxW1KUFvviqSIX9ybFpfYQB8YCF3zlN9GVqt+Ig/bfFAdV1I2nDVs4KZ3vbqWPOqBB1I015X7N8QOX4EbicEzg= X-Received: by 2002:a2e:824e:: with SMTP id j14mr16683903ljh.445.1625606398404; Tue, 06 Jul 2021 14:19:58 -0700 (PDT) MIME-Version: 1.0 References: <20210706195233.h6w4cm73oktfqpgz@habkost.net> <20210706211606.ezme3xvwztagbjqy@gupta-dev2.localdomain> In-Reply-To: <20210706211606.ezme3xvwztagbjqy@gupta-dev2.localdomain> From: Eduardo Habkost Date: Tue, 6 Jul 2021 17:19:42 -0400 Message-ID: Subject: Re: [PATCH 4/4] x86/tsx: Add cmdline tsx=fake to not clear CPUID bits RTM and HLE To: Pawan Gupta Cc: Thomas Gleixner , Borislav Petkov , Jonathan Corbet , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , x86@kernel.org, "H. Peter Anvin" , "Paul E. McKenney" , Randy Dunlap , Andrew Morton , "Maciej W. Rozycki" , Viresh Kumar , Vlastimil Babka , Tony Luck , Paolo Bonzini , Sean Christopherson , Kyung Min Park , Fenghua Yu , Ricardo Neri , Tom Lendacky , Juergen Gross , Krish Sadhukhan , Kan Liang , Joerg Roedel , Victor Ding , Srinivas Pandruvada , Brijesh Singh , Dave Hansen , Mike Rapoport , Anthony Steinhauser , Anand K Mistry , Andi Kleen , Miguel Ojeda , Nick Desaulniers , Joe Perches , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, kvm@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 6, 2021 at 5:15 PM Pawan Gupta wrote: > > On 06.07.2021 15:52, Eduardo Habkost wrote: > >On Wed, Jun 09, 2021 at 02:14:39PM -0700, Pawan Gupta wrote: > >> On CPUs that deprecated TSX, clearing the enumeration bits CPUID.RTM and > >> CPUID.HLE may not be desirable in some corner cases. Like a saved guest > >> would refuse to resume if it was saved before the microcode update > >> that deprecated TSX. > > > >Why is a global option necessary to allow those guests to be > >resumed? Why can't KVM_GET_SUPPORTED_CPUID always return the HLE > >and RTM bits as supported when the host CPU has them? > > Yes, the global option is unnecessary and this patch was dropped in v2. Was the behaviour this patch originally tried to fix changed in v2 as well? Is it going to be possible to resume a HLE=1,RTM=1 VM on a TSX_FORCE_ABORT=1 host with no extra kernel command line options needed? -- Eduardo