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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 15216C4321A for ; Fri, 28 Jun 2019 16:37:01 +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 E210D2083B for ; Fri, 28 Jun 2019 16:37:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kMZ0KdA+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E210D2083B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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=NuUMN1cbv7gq7M3mkMKYKAM23jmopiZOZ9ielxUJcoY=; b=kMZ0KdA+bX0ZVR 2bxzJKWmZwZ5hDKzLnMD+5EtNF+n1LkZsSq6arJQTKcAln6C0f2OCn0/NNs1QzbRYMmSHsxxcRClj d41WBKtCwVXngv91pcBmYHoLuQv2RDDqKeyayMcoI1Ek2XOpOvCEaZBl2lyBlN+oX8YXo5+NOaXXm fsylp7QFoPkybHtg5u1EsIVaZJcoGX/s8PzYXMIxJXW2vHNdLpDicrIBIdoJKs0Fe3HcayB9CmP8m cSf2k56cG+TmUyq/D/M07JEE3BJGfU4cWQRBSwyTTHMHeTFKXHHxJzLZC3GYEPRucMqIBGCNQ0AK6 br2pwY5cvMJApq0R8LFA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hgtrm-0004bM-Ao; Fri, 28 Jun 2019 16:36:50 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hgtrj-0004at-UN for linux-arm-kernel@lists.infradead.org; Fri, 28 Jun 2019 16:36:49 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9A47028; Fri, 28 Jun 2019 09:36:45 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.78]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0F6843F706; Fri, 28 Jun 2019 09:36:44 -0700 (PDT) Date: Fri, 28 Jun 2019 17:36:42 +0100 From: Catalin Marinas To: Mark Brown Subject: Re: [PATCH v2] arm64: Add initial support for E0PD Message-ID: <20190628163642.GB56463@arrakis.emea.arm.com> References: <20190627141532.6452-1-broonie@kernel.org> <20190628110430.ffdqy5on3retyr42@willie-the-truck> <20190628123040.GG5379@sirena.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190628123040.GG5379@sirena.org.uk> 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-20190628_093648_027399_4D2C26C9 X-CRM114-Status: GOOD ( 13.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Will Deacon , linux-arm-kernel@lists.infradead.org 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 Fri, Jun 28, 2019 at 01:30:40PM +0100, Mark Brown wrote: > On Fri, Jun 28, 2019 at 12:04:30PM +0100, Will Deacon wrote: > > Thanks for the quick v2, although I still don't see the rush to merge this > > without the associated kaslr/kpti changes we've been discussing. It's not > > like there's a whole load of 8.5 silicon we're rushing to support. > > It's largely on the general theory that it's better to carry less out of > tree code - there's less diff to manage, less chance of collisions with > other work (in either direction), and less pending review to worry about. > So long as something represents forward progress I tend to work on the > basis of why not rather than why. A reason is that once we add the support for disabling kpti based on the E0PD feature, this patch may turn out to be slightly different (for example, you may add a common has_e0pd() check that is called from both unmap_kernel_at_el0() and the E0PD arm64_features[] entry). Given that both patches would be relatively small, I agree with Will that there is no rush to merge them independently. -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel