From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753179AbcCJTT6 (ORCPT ); Thu, 10 Mar 2016 14:19:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:37942 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752630AbcCJTTw (ORCPT ); Thu, 10 Mar 2016 14:19:52 -0500 Date: Thu, 10 Mar 2016 20:19:33 +0100 From: Borislav Petkov To: Paul Gortmaker Cc: Toshi Kani , Richard Purdie , Toshi Kani , Bruce Ashfield , "Hart, Darren" , "saul.wold" , linux-kernel@vger.kernel.org Subject: Re: runtime regression with "x86/mm/pat: Emulate PAT when it is disabled" Message-ID: <20160310191933.GC2194@pd.tnic> References: <1457366596.15454.281.camel@hpe.com> <20160307210852.GC26051@windriver.com> <1457393912.15454.419.camel@hpe.com> <20160307235328.GD26051@windriver.com> <1457398578.15454.421.camel@hpe.com> <1457400913.15454.435.camel@hpe.com> <20160310144250.GG23251@windriver.com> <1457628591.15454.542.camel@hpe.com> <20160310172029.GA2194@pd.tnic> <20160310190429.GI23251@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20160310190429.GI23251@windriver.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 10, 2016 at 02:04:29PM -0500, Paul Gortmaker wrote: > So, I guess that is a qemu bug? If there is no real silicon out there > that has no MTRR but does claim PAT, then qemu32 is a flawed CPU type? Well, AFAICT, "qemu32" is emulating something PPRO-like: #define PPRO_FEATURES (CPUID_FP87 | CPUID_DE | CPUID_PSE | CPUID_TSC | \ CPUID_MSR | CPUID_MCE | CPUID_CX8 | CPUID_PGE | CPUID_CMOV | \ CPUID_PAT | CPUID_FXSR | CPUID_MMX | CPUID_SSE | CPUID_SSE2 | \ ^^^^^^^^^ and that one advertizes PAT but not MTRRs. I need to go dig into history to find out what PPRO actually supported. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --