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=-2.3 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 7D1ECC5CFFE for ; Tue, 11 Dec 2018 15:30:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49FE820849 for ; Tue, 11 Dec 2018 15:30:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 49FE820849 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727077AbeLKPaZ (ORCPT ); Tue, 11 Dec 2018 10:30:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56442 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726839AbeLKPaY (ORCPT ); Tue, 11 Dec 2018 10:30:24 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id E21B53082DDA; Tue, 11 Dec 2018 15:30:23 +0000 (UTC) Received: from redhat.com (ovpn-112-59.ams2.redhat.com [10.36.112.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9EFA45D717; Tue, 11 Dec 2018 15:30:20 +0000 (UTC) Date: Tue, 11 Dec 2018 15:30:17 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Paolo Bonzini Cc: Eduardo Habkost , Borislav Petkov , =?utf-8?B?SsO2cmcgUsO2ZGVs?= , Andre Przywara , kvm ML , lkml , Tom Lendacky , Eric Blake Subject: Re: kvm: RDTSCP on AMD Message-ID: <20181211153017.GN921@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20181210181328.GA762@zn.tnic> <20181210183730.GJ4669@habkost.net> <20181210184153.GB5482@zn.tnic> <20181210190600.GK4669@habkost.net> <20181210194258.GD5482@zn.tnic> <20181210200843.GN4669@habkost.net> <20181211103839.GC921@redhat.com> <20181211115546.GQ4669@habkost.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Tue, 11 Dec 2018 15:30:24 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 11, 2018 at 04:23:51PM +0100, Paolo Bonzini wrote: > On 11/12/18 12:55, Eduardo Habkost wrote: > >> - Debian Jessie: 4.5 > >> - Debian Stretch: 4.5 > >> - RHEL-7: 3.10 > >> - Ubuntu LTS (Xenial): 4.5 > >> - OpenSUSE Leap 15: 4.12.14 > >> > >> So we can't require Linux 4.5 as a minimum version at this time. > > I'd like us to take a step back and consider what exactly > > "support" means here. QEMU will still work on older kernels if > > we add RDTSCP to the CPU models, but at the same time I would > > like to document that our strict runnability guarantees may not > > be kept if running Linux < 4.5. > > Anyway RHEL does have RDTSC support for AMD, and a bunch of other stuff. > The frankenkernel's KVM is somewhere between 4.5 and 4.10, with a dash > of 4.20 of course. :) Great, then, this is a non-issue - we just need to mention that fact in the commit that sets the min version for the kernel Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|