From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F98FC04EB9 for ; Wed, 5 Dec 2018 15:54:02 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3177820879 for ; Wed, 5 Dec 2018 15:54:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="NDk7L8ph" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=YSjClqDLsHTmnN4iogZeEsb078VvXKwqnjQd6rryaUM=; b=NDk7L8phhL9Dmu CfzWqfs2zSSUNuwbbUbspOpJHTxeXBaPFLr4yB8F9zdUlhQtvgjLp9A+bPJJjQ1u5KRGJdQSGYeE9 f+IvHCxXOkQe+aIZz3Ljog0m2TkAzhUvbPcHuXFVzQmutdyvxOmruFKHKLQXLnVNhVRBg0fJMrVWB T7FlMT/UsfYBJFRXgRYmfh8MoJvoC2bkRSV2atTIlZaUZUL3AFmjRuFUNNucLh1Shfac3eMQvOx33 TXbx0o93k4xGAhognEIFSOj5a44j//VWxHFkCPdweOymWyxetx9vz8m3mnM7rajK32lD5T9Aoo2tD b0yExDhiYXDYm0WJwf3w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUZUs-000801-4B; Wed, 05 Dec 2018 15:53:58 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUZUp-0007yx-3D for linux-arm-kernel@lists.infradead.org; Wed, 05 Dec 2018 15:53:56 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 310EE80D; Wed, 5 Dec 2018 07:53:44 -0800 (PST) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.113]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CDE8D3F5AF; Wed, 5 Dec 2018 07:53:42 -0800 (PST) Date: Wed, 5 Dec 2018 15:53:40 +0000 From: Catalin Marinas To: Suzuki K Poulose Subject: Re: Unexpected variation in SYS_ID_AA64MMFR0_EL1 Message-ID: <20181205155339.GC27881@arrakis.emea.arm.com> References: <44c18e70-e4d9-5e4d-1326-aa1f88a16315@arm.com> <20181203153232.no5yiliofqtfelfu@localhost> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181205_075355_141988_7F57904D X-CRM114-Status: GOOD ( 21.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Ard Biesheuvel , marc.w.gonzalez@free.fr, Bjorn Andersson , Dave Martin , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Dec 05, 2018 at 10:17:38AM +0000, Suzuki K Poulose wrote: > > > On 03/12/2018 15:32, Catalin Marinas wrote: > > On Fri, Nov 30, 2018 at 01:23:28PM +0000, Suzuki K. Poulose wrote: > > > On 30/11/2018 13:12, Ard Biesheuvel wrote: > > > > On Fri, 30 Nov 2018 at 13:15, Marc Gonzalez wrote: > > > > > On an APQ8098-based system, for cores 4-7 (little cores?), the kernel prints: > > > > > > > > > > [ 0.179055] CPU features: SANITY CHECK: Unexpected variation in SYS_ID_AA64MMFR0_EL1. > > > > > Boot CPU: 0x00000000001122, CPU4: 0x00000000101122 > > > > > > > > > > TGran16, [23:20] > > > > > Support for 16KB memory translation granule size: > > > > > 0x1 Indicates that the 16KB granule is supported. > > > > > > > > > > Since this is a pr_warn, I get the feeling something is not quite right. > > > > > Is there something to fix? Is it a problem that the big and little cores > > > > > don't support exactly the same granule sizes? > > > > > > > > > > > > > That looks like a false positive to me. We should only care about the > > > > page size we are running with. > > > > > > Unless you run a VM, which is going to use 16K translation. But this may be > > > fine with the current kernels, where we emulate the SANITISED registers > > > for the guests. > > > > I think that's sanitised now for KVM, so we could downgrade the feature > > to FTR_NONSTRICT. > > Yes, the only caveat is we must make sure that the patch somehow reflect > the KVM changes to prevent backports assuming that it is safe to change them > without the KVM bits. We can add a "Cc: stable # " to make the requirement clear. We should probably also limit the Cc: stable to the kernel version where KVM started trapping this register. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel