Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751823AbaLPNIo (ORCPT ); Tue, 16 Dec 2014 08:08:44 -0500 Received: from mail-qg0-f41.google.com ([209.85.192.41]:48882 "EHLO mail-qg0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750832AbaLPNIn (ORCPT ); Tue, 16 Dec 2014 08:08:43 -0500 Message-ID: <54902ED8.7010707@hurleysoftware.com> Date: Tue, 16 Dec 2014 08:08:40 -0500 From: Peter Hurley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: jongman.heo@samsung.com, Juergen Gross , "linux-kernel@vger.kernel.org" , Thomas Hellstrom Subject: Re: [3.18+] Can't boot with commit bd809af1 ("x86: Enable PAT to use cache mode translation tables") References: <1973992816.47941418712371282.JavaMail.weblogic@epmlwas09d> In-Reply-To: <1973992816.47941418712371282.JavaMail.weblogic@epmlwas09d> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org VMware guys probably already know this but just in case [ +cc Thomas Hellstrom ] Jongman - you need to fix your mailer to use plaintext and not base64. On 12/16/2014 01:46 AM, Jongman Heo wrote: >> Sender : Juergen Gross >> On 12/16/2014 07:29 AM, Jongman Heo wrote: >>>> Sender : Juergen Gross >>>> On 12/16/2014 05:40 AM, Jongman Heo wrote: >>>>>> Sender : Juergen Gross >>>>>> On 12/15/2014 08:52 AM, Jongman Heo wrote: >>>>>>>> Sender : Juergen Gross >>>>>>>> On 12/14/2014 06:07 AM, 허종만 wrote: >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> My Linux virtual machine on (Windows) VMWare workstation 10 can't boot with following commit. >>>>>>>>> >>>>>>>>> commit bd809af16e3ab1f8d55b3e2928c47c67e2a865d2 >>>>>>>>> Author: Juergen Gross >>>>>>>>> Date: Mon Nov 3 14:02:03 2014 +0100 >>>>>>>>> >>>>>>>>> x86: Enable PAT to use cache mode translation tables >>>>>>>>> >>>>>>>>> Unfortunately I can't see any console log. >>>>>>>> >>>>>>>> Hmm, weird. Could you provide some more information? >>>>>>>> >>>>>>>> Kernel config, hardware used, /proc/cpuinfo of working kernel? >>>>>>>> Anything you see with earlyprintk enabled? >>>>>>>> >>>>>>>> >>>>>>>> Juergen >>>>>>> >>>>>>> (Sorry for resending this email, previous one bounced from mailing list due to HTML format) >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> I'm using Fedora 21, with custom built kernel. >>>>>>> Host PC is windows 7 64-bit, and running VMWare workstation 10 for guest Fedora Linux. >>>>>>> >>>>>>> With earlyprintk, just following message is printed. >>>>>>> >>>>>>> early console in setup code >>>>>>> >>>>>>> and nothing more... >>>>>> >>>>>> Can you try attached diagnostic patch, please? I suspect a problem >>>>>> regarding VMWares PAT emulation... >>>>>> >>>>>> >>>>>> Juergen >>>>> >>>>> Hi, >>>>> >>>>> With the commit reverted, the patch doesn't apply. >>>> >>>> Sure. >>>> >>>>> Without revert, kernel (patch applied) doesn't boot and I can't see any message. >>>> >>>> What are your kernel parameters? There must be some message with the >>>> diagnostic patch, as the first pr_info() is called before any other >>>> part of the critical patch is becoming active. Could it be you have >>>> instructed the kernel to be "quiet"? I'd recommend: >>>> >>>> earlyprintk=vga ignore_loglevel >>>> >>>> and no quiet. I don't know VMWare settings, so may be you can use >>>> earlyprintk=ttyS0 instead of vga. >>>> >>>>> >>>>> Let me show you my PAT values (the commit reverted) >>>>> >>>>> # dmesg | grep PAT >>>>> [ 0.000000] x86 PAT enabled: cpu 0, old 0x0, new 0x7010600070106 >>>>> [ 0.314631] x86 PAT enabled: cpu 3, old 0x0, new 0x7010600070106 >>>>> [ 0.314703] x86 PAT enabled: cpu 1, old 0x0, new 0x7010600070106 >>>>> [ 0.314780] x86 PAT enabled: cpu 2, old 0x0, new 0x7010600070106 >>>>> [ 0.314852] x86 PAT enabled: cpu 4, old 0x0, new 0x7010600070106 >>>>> [ 0.314923] x86 PAT enabled: cpu 0, old 0x0, new 0x7010600070106 >>>>> [ 0.314997] x86 PAT enabled: cpu 6, old 0x0, new 0x7010600070106 >>>>> [ 0.315069] x86 PAT enabled: cpu 7, old 0x0, new 0x7010600070106 >>>>> [ 0.315142] x86 PAT enabled: cpu 5, old 0x0, new 0x7010600070106 >>>> >>>> These are the expected values. But these values are the ones which are >>>> written, not the ones which have been read from the PAT MSR again. >>>> >>>> Without applying the critical patch you could add: >>>> >>>> rdmsrl(MSR_IA32_CR_PAT, pat); >>>> printk(KERN_INFO "PAT read: cpu %d, 0x%Lx\n", smp_processor_id(), pat); >>>> >>>> at the end of pat_init() to verify VMWare is handling reads of the PAT >>>> MSR properly. >>>> >>>> Juergen >>>> >>> >>> Hi, >>> >>> With earlyprintk=vga, I can see the log. >>> But due to call trace, I can't see what the pat value is. >>> >>> Call chain is as follows. >>> >>> i386_start_kernel -> start_kernel -> setup_arch -> >>> mtrr_bp_init -> get_mtrr_state -> pat_init -> >>> pat_init_cache_mode_entry -> update_cache_mode_entry -> >>> early_idt_handler -> dump_stack >>> >>> So, I blocked update_cache_mode_entry() call like below... >>> >>> --- a/arch/x86/mm/pat.c >>> +++ b/arch/x86/mm/pat.c >>> @@ -182,11 +182,12 @@ void pat_init_cache_modes(void) >>> u64 pat; >>> >>> rdmsrl(MSR_IA32_CR_PAT, pat); >>> + pr_info("read pat %0llx\n", pat); >>> pat_msg[32] = 0; >>> for (i = 7; i >= 0; i--) { >>> cache = pat_get_cache_mode((pat >> (i * 8)) & 7, >>> pat_msg + 4 * i); >>> - update_cache_mode_entry(i, cache); >>> + //update_cache_mode_entry(i, cache); >>> } >>> pr_info("PAT configuration [0-7]: %s\n", pat_msg); >>> } >>> @@ -238,9 +239,13 @@ void pat_init(void) >>> rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); >>> >>> wrmsrl(MSR_IA32_CR_PAT, pat); >>> + pr_info("about to write pat %0llx\n", pat); >>> >>> if (boot_cpu) >>> pat_init_cache_modes(); >>> + >>> + rdmsrl(MSR_IA32_CR_PAT, pat); >>> + printk(KERN_INFO "PAT read: cpu %d, 0x%Lx\n", smp_processor_id(), pat); >>> } >>> >>> >>> Then boot is fine, and PAT values are as follows. >>> >>> >>> # dmesg|grep -i "pat " >>> [ 0.000000] about to write pat 7010600070106 >>> [ 0.000000] read pat 0 >>> [ 0.000000] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.000000] PAT read: cpu 0, 0x0 >>> [ 0.320559] about to write pat 7010600070106 >>> [ 0.320876] read pat 0 >>> [ 0.321090] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.321260] PAT read: cpu 5, 0x0 >>> [ 0.321403] about to write pat 7010600070106 >>> [ 0.321818] read pat 0 >>> [ 0.322033] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.322205] PAT read: cpu 6, 0x0 >>> [ 0.322334] about to write pat 7010600070106 >>> [ 0.322417] read pat 0 >>> [ 0.322479] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.322573] PAT read: cpu 0, 0x0 >>> [ 0.322703] about to write pat 7010600070106 >>> [ 0.323012] read pat 0 >>> [ 0.323228] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.323400] PAT read: cpu 1, 0x0 >>> [ 0.323537] about to write pat 7010600070106 >>> [ 0.323833] read pat 0 >>> [ 0.324055] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.324224] PAT read: cpu 7, 0x0 >>> [ 0.324362] about to write pat 7010600070106 >>> [ 0.324662] read pat 0 >>> [ 0.324877] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.325048] PAT read: cpu 2, 0x0 >>> [ 0.325185] about to write pat 7010600070106 >>> [ 0.325483] read pat 0 >>> [ 0.325695] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.325863] PAT read: cpu 4, 0x0 >>> [ 0.325997] about to write pat 7010600070106 >>> [ 0.326288] read pat 0 >>> [ 0.326507] PAT configuration [0-7]: UC UC UC UC UC UC UC UC >>> [ 0.326677] PAT read: cpu 3, 0x0 >> >> Okay, so VMWare doesn't seem to return the correct PAT MSR value. >> >> I suggest you try "nopat" as kernel option. This should disable all the >> PAT handling and VMWare can't wreck the kernel this way. >> >> I'll write a patch which detects this VMWare bug by checking the PAT >> value after writing it. >> >> Thanks for reporting that case, >> >> >> Juergen >> >> > > OK, my VMWare works with "nopat" option. > > Thanks~.N -- 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/