This message generated a parse failure. Raw output follows here. Please use 'back' to navigate. From devnull@lkml.org Sun May 12 14:49:05 2024 >From spaans Wed Jan 7 06:03:41 2015 Received: from pop.ziggo.nl [212.54.42.19] by squeeze.vs19.net with POP3 (fetchmail-6.3.21) for (single-drop); Wed, 07 Jan 2015 06:03:41 +0100 (CET) Received: from md5.tb.mail.iss.local ([212.54.42.143]) by mc5.tb.mail.iss.local (Dovecot) with LMTP id 9f9ZBAC9rFQOTgAAh0Kp1A for ; Wed, 07 Jan 2015 05:58:46 +0100 Received: from mx16.tb.mail.iss.as9143.net ([212.54.42.143]) by md5.tb.mail.iss.local (Dovecot) with LMTP id Mqs3GVLqgFT+BgAA7jSZHA ; Wed, 07 Jan 2015 06:00:55 +0100 Received: from vger.kernel.org ([209.132.180.67]) by mx16.tb.mail.iss.as9143.net with esmtp (Exim 4.82) (envelope-from ) id 1Y8ihd-0007g3-Ay for bmw12-lkml@ziggo.nl; Wed, 07 Jan 2015 05:58:45 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755100AbbAGE6b (ORCPT ); Tue, 6 Jan 2015 23:58:31 -0500 Received: from cantor2.suse.de ([195.135.220.15]:56217 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752347AbbAGE6a (ORCPT ); Tue, 6 Jan 2015 23:58:30 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 98013AB09; Wed, 7 Jan 2015 04:58:27 +0000 (UTC) Message-Id: <54ACBCF2.3010807@suse.com> Date: Wed, 07 Jan 2015 05:58:26 +0100 From: Juergen Gross User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 Mime-Version: 1.0 To: Alok Kataria Cc: "hpa@zytor.com" , "tglx@linutronix.de" , "linux-kernel@vger.kernel.org" , David Dunn , "mingo@redhat.com" , "x86@kernel.org" , "jongman.h Subject: Re: [PATCH] x86: don't rely on VMWare emulating PAT MSR correctly References: <1418723914-9736-1-git-send-email-jgross@suse.com> <1418792295.4473.70.camel@akataria-dtop.eng.vmware.com> In-Reply-To: <1418792295.4473.70.camel@akataria-dtop.eng.vmware.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-Id: X-Mailing-List: linux-kernel@vger.kernel.org X-Ziggo-spamsetting: Instelling=Gemiddeld Scorelimiet=14 X-Ziggo-spambar: / X-Ziggo-spamscore: -0.3 X-Ziggo-spamreport: BAYES_00=-1.9,CM_CTENC_8BIT=0.1,CM_SPACED_DATE=0.5,HEADER_FROM_DIFFERENT_DOMAINS=0.001,L_TAB_IN_FROM=2,RCVD_IN_JMF_W=-1,RCVD_IN_MSPIKE_H3=-0.01,RCVD_IN_MSPIKE_WL=-0.01,T_RP_MATCHES_RCVD=-0.01 X-Ziggo-Spam-Status: No X-Spam-Status: No X-Spam-Flag: No x86 maintainers, could you please consider taking my patch? There have been several reports now regarding this issue, all could be fixed using my patch. Juergen On 12/17/2014 05:57 AM, Alok Kataria wrote: > Hi, > > On Tue, 2014-12-16 at 10:58 +0100, Juergen Gross wrote: >> VMWare seems not to emulate the PAT MSR correctly: reaeding >> MSR_IA32_CR_PAT returns 0 even after writing another value to it. >> >> Detect this bug and don't use the read value if it is 0. >> >> Commit bd809af16e3ab1f8d55b3e2928c47c67e2a865d2 ("x86: Enable PAT to >> use cache mode translation tables") triggers this VMWare bug when the >> kernel is booted as a VMWare guest. > > Thanks for taking care of this, we are fine with this workaround. On > newer version of our product, where PAT is virtualized correctly on our > platform we will go back to using PAT, I will give it a spin sometime > later to verify it. > > Acked-by: Alok N Kataria > >> Reported-by: Jongman Heo >> Signed-off-by: Juergen Gross >> Tested-by: Jongman Heo >> --- >> arch/x86/mm/pat.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c >> index edf299c..7ac6869 100644 >> --- a/arch/x86/mm/pat.c >> +++ b/arch/x86/mm/pat.c >> @@ -234,8 +234,13 @@ void pat_init(void) >> PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); >> >> /* Boot CPU check */ >> - if (!boot_pat_state) >> + if (!boot_pat_state) { >> rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); >> + if (!boot_pat_state) { >> + pat_disable("PAT read returns always zero, disabled."); >> + return; >> + } >> + } >> >> wrmsrl(MSR_IA32_CR_PAT, pat); >> > > Alok > N�����r��y���b�X��ǧv�^�)޺{.n�+����{����zX����ܨ}���Ơz�&j:+v�������zZ+��+zf���h���~����i���z��w���?����&�)ߢf��^jǫy�m��@A�a��� 0��h��i > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/