Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754764AbbLKW1P (ORCPT ); Fri, 11 Dec 2015 17:27:15 -0500 Received: from mail-ob0-f173.google.com ([209.85.214.173]:34427 "EHLO mail-ob0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751803AbbLKW1N (ORCPT ); Fri, 11 Dec 2015 17:27:13 -0500 MIME-Version: 1.0 In-Reply-To: References: <23b2515da9d06b198044ad83ca0a15ba38c24e6e.1449861203.git.tony.luck@intel.com> <3908561D78D1C84285E8C5FCA982C28F39F82D87@ORSMSX114.amr.corp.intel.com> <3908561D78D1C84285E8C5FCA982C28F39F82EEF@ORSMSX114.amr.corp.intel.com> From: Andy Lutomirski Date: Fri, 11 Dec 2015 14:26:53 -0800 Message-ID: Subject: Re: [PATCHV2 3/3] x86, ras: Add mcsafe_memcpy() function to recover from machine checks To: Dan Williams Cc: "Luck, Tony" , Ingo Molnar , Borislav Petkov , Andrew Morton , Andy Lutomirski , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , linux-nvdimm , X86 ML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1213 Lines: 29 On Fri, Dec 11, 2015 at 2:20 PM, Dan Williams wrote: > On Fri, Dec 11, 2015 at 2:17 PM, Luck, Tony wrote: >>> Also, would it be more straightforward if the mcexception landing pad >>> looked up the va -> pa mapping by itself? Or is that somehow not >>> reliable? >> >> If we did get all the above right, then we could have >> target use virt_to_phys() to convert to physical ... >> I don't see that this part would be a problem. > > virt_to_phys() implies a linear address. In the case of the use in > the pmem driver we'll be using an ioremap()'d address off somewherein > vmalloc space. There's always slow_virt_to_phys. Note that I don't fundamentally object to passing the pa to the fixup handler. I just think we should try to disentangle that from figuring out what exactly the failure was. Also, are there really PCOMMIT-capable CPUs that still forcibly broadcast MCE? If, so, that's unfortunate. --Andy -- 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/