From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id E147A6B7A25 for ; Thu, 6 Dec 2018 07:26:15 -0500 (EST) Received: by mail-ed1-f71.google.com with SMTP id l45so308792edb.1 for ; Thu, 06 Dec 2018 04:26:15 -0800 (PST) Received: from EUR04-HE1-obe.outbound.protection.outlook.com (mail-eopbgr70077.outbound.protection.outlook.com. [40.107.7.77]) by mx.google.com with ESMTPS id gx11-v6si178526ejb.297.2018.12.06.04.26.14 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 06 Dec 2018 04:26:14 -0800 (PST) From: Steve Capper Subject: Re: [PATCH V4 5/6] arm64: mm: introduce 52-bit userspace support Date: Thu, 6 Dec 2018 12:26:12 +0000 Message-ID: <20181206122603.GB17473@capper-debian.cambridge.arm.com> References: <20181205164145.24568-1-steve.capper@arm.com> <20181205164145.24568-6-steve.capper@arm.com> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-ID: <1F5D34DCB0DB9E419B0ABB0B65633BE6@eurprd08.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Suzuki Poulose Cc: "linux-mm@kvack.org" , "linux-arm-kernel@lists.infradead.org" , Catalin Marinas , Will Deacon , "jcm@redhat.com" , "ard.biesheuvel@linaro.org" , nd On Wed, Dec 05, 2018 at 06:22:27PM +0000, Suzuki K Poulose wrote: > Hi Steve, >=20 [...]=20 > I think we may need a check for the secondary CPUs to make sure that they= have > the 52bit support once the boot CPU has decided to use the feature and fa= il the > CPU bring up (just like we do for the granule support). >=20 > Suzuki Hi Suzuki, I have just written a patch to detect a mismatch between 52-bit VA that is being tested now. As 52-bit kernel VA support is coming in future, the patch checks for a mismatch during the secondary boot path and, if one is found, prevents the secondary from booting (and displays an error message to the user). Cheers, --=20 Steve