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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4EA9AC433FE for ; Thu, 20 Oct 2022 09:58:40 +0000 (UTC) Received: from localhost ([::1]:43974 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1olSJy-0001Fb-Tq for qemu-devel@archiver.kernel.org; Thu, 20 Oct 2022 05:58:39 -0400 Received: from [::1] (helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1olSIv-0004YJ-SR for qemu-devel@archiver.kernel.org; Thu, 20 Oct 2022 05:57:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39634) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olS6U-0003gE-Hp; Thu, 20 Oct 2022 05:44:43 -0400 Received: from ams.source.kernel.org ([145.40.68.75]:57600) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olS6S-0005sh-T5; Thu, 20 Oct 2022 05:44:42 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 62EEDB8269E; Thu, 20 Oct 2022 09:44:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 214A1C433C1; Thu, 20 Oct 2022 09:44:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666259068; bh=syP/42BpcfKg6GmOnczk9Khh66b+HJtdfVjHn7ffgao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BWmMxcTiVuHeh/Ef1JFs1lsGPgzG1tXERrJolxF07yVfXl3gQcY+UfwK4doFafuND 9UTv7ZYmNiTPk0X0eQNRQ79Btu3CuU13e+J9PVxV+U/48h8HOAb1jz/QlS3WgZD2/1 L1/+26moK/CzYEjaTTtiWaxqW1Rj4o+bD7Lahos+NnJVpAsObpRVgx6UdnYd8c3gME vzWYf7+sz/bYYrGxIndFgkjeiCCNocBCz18VCqW+tXOucucNBb1aEYGLwsc+ljCLPe rdigOIB1tJk+EFrO0oHDFJ9YiOeukTc2qrzqMdb4ePskU6jF+oYQEyFIp78I1Bzwio 1aDCxAk03IMbg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1olS6D-000Cl7-Tv; Thu, 20 Oct 2022 10:44:26 +0100 Date: Thu, 20 Oct 2022 10:44:25 +0100 Message-ID: <865ygeg77q.wl-maz@kernel.org> From: Marc Zyngier To: Gavin Shan Cc: eric.auger@redhat.com, qemu-arm@nongnu.org, qemu-devel@nongnu.org, cohuck@redhat.com, zhenyzha@redhat.com, richard.henderson@linaro.org, peter.maydell@linaro.org, shan.gavin@gmail.com Subject: Re: [PATCH v5 6/6] hw/arm/virt: Add 'compact-highmem' property In-Reply-To: <6566e453-9b05-7092-f112-ea9e523be8b4@redhat.com> References: <20221011231832.149839-1-gshan@redhat.com> <20221011231832.149839-7-gshan@redhat.com> <9a43b31a-63d7-d312-870d-168df1b41921@redhat.com> <6566e453-9b05-7092-f112-ea9e523be8b4@redhat.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: gshan@redhat.com, eric.auger@redhat.com, qemu-arm@nongnu.org, qemu-devel@nongnu.org, cohuck@redhat.com, zhenyzha@redhat.com, richard.henderson@linaro.org, peter.maydell@linaro.org, shan.gavin@gmail.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Received-SPF: pass client-ip=145.40.68.75; envelope-from=maz@kernel.org; helo=ams.source.kernel.org X-Spam_score_int: -73 X-Spam_score: -7.4 X-Spam_bar: ------- X-Spam_report: (-7.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.256, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 20 Oct 2022 00:57:32 +0100, Gavin Shan wrote: > > For Marc's suggestion to add properties so that these high memory > regions can be disabled by users. I can add one patch after this one > to introduce the following 3 properties. Could you please confirm > the property names are good enough? It's nice if Marc can help to > confirm before I'm going to work on next revision. > > "highmem-ecam": "on"/"off" on vms->highmem_ecam > "highmem-mmio": "on"/"off" on vms->highmem_mmio > "highmem-redists": "on"/"off" on vms->highmem_redists I think that'd be reasonable, and would give the user some actual control over what gets exposed in the highmem region. I guess that the annoying thing with these options is that they allow the user to request conflicting settings (256 CPUs and highmem-redists=off, for example). You'll need to make this fail more or less gracefully. Thanks, M. -- Without deviation from the norm, progress is not possible.