From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f171.google.com (mail-ob0-f171.google.com [209.85.214.171]) by kanga.kvack.org (Postfix) with ESMTP id BFD876B0253 for ; Fri, 11 Dec 2015 17:27:13 -0500 (EST) Received: by obbsd4 with SMTP id sd4so44104989obb.0 for ; Fri, 11 Dec 2015 14:27:13 -0800 (PST) Received: from mail-ob0-x229.google.com (mail-ob0-x229.google.com. [2607:f8b0:4003:c01::229]) by mx.google.com with ESMTPS id fj3si8933749obc.64.2015.12.11.14.27.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 11 Dec 2015 14:27:13 -0800 (PST) Received: by obc18 with SMTP id 18so92925926obc.2 for ; Fri, 11 Dec 2015 14:27:13 -0800 (PST) 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 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: 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 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, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org