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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D5A3AC64E7B for ; Tue, 1 Dec 2020 15:00:01 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (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 3EBBC2076C for ; Tue, 1 Dec 2020 15:00:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="c67GUp81" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3EBBC2076C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+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=merlin.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=OJ1TkY0YRktPMQnX6ah7UDDqc+vvQu6Oln9crW4bPao=; b=c67GUp81iJNsGZFmjcojl+y0B gO0ABkkcxBKg+/+aQ5v7vhXYZbGLwqyeRO3aZgCLyORdJh6p5njAgYBqz2UTMZZvArrq3ahiXOxLt QVv5zx7eUaaiykxlwkq+CHLCjxppizRXjOdBAlj1y+hEtjF1BDvDeiqqVFeasdvqteT4HT28qHdaT kbmtdzdsMadp66A40wiHB8PT59kSsD09zZ6yLzbHDDnepxFJiM9NuELHTrr97+ygc0+VSvk0s6VaM /xPYDMP+h2Ugg6K7mkzwZ03vQzJE04sr1Ayfr17s8Qc5SvE8ZgOlQ7JVy/ifxP4Vx7zWna4kgdmHJ S/jAczjyg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kk77D-0006Fa-7y; Tue, 01 Dec 2020 14:58:51 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kk77A-0006Ex-Vg for linux-arm-kernel@lists.infradead.org; Tue, 01 Dec 2020 14:58:49 +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 A6CCA30E; Tue, 1 Dec 2020 06:58:47 -0800 (PST) Received: from C02TD0UTHF1T.local (unknown [10.57.30.155]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 444ED3F575; Tue, 1 Dec 2020 06:58:43 -0800 (PST) Date: Tue, 1 Dec 2020 14:58:40 +0000 From: Mark Rutland To: David Brazdil Subject: Re: [PATCH v3 06/23] kvm: arm64: Add kvm-arm.protected early kernel parameter Message-ID: <20201201145840.GC86881@C02TD0UTHF1T.local> References: <20201126155421.14901-1-dbrazdil@google.com> <20201126155421.14901-7-dbrazdil@google.com> <20201127163254.zxdrszlveaxhluwn@bogus> <20201201131913.u7m2eifvtus74dra@google.com> <20201201140734.GA86881@C02TD0UTHF1T.local> <20201201144349.bglz7yicc3peixe6@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201201144349.bglz7yicc3peixe6@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201201_095849_095893_1C9CD1DB X-CRM114-Status: GOOD ( 27.57 ) 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: Lorenzo Pieralisi , kernel-team@android.com, Jonathan Corbet , Catalin Marinas , Sudeep Holla , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Suzuki K Poulose , James Morse , linux-arm-kernel@lists.infradead.org, Marc Zyngier , Tejun Heo , Dennis Zhou , Christoph Lameter , Will Deacon , kvmarm@lists.cs.columbia.edu, Julien Thierry Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Dec 01, 2020 at 02:43:49PM +0000, David Brazdil wrote: > > > > be just me, but if you agree please update so that it doesn't give remote > > > > idea that it is not valid on VHE enabled hardware. > > > > > > > > I was trying to run this on the hardware and was trying to understand the > > > > details on how to do that. > > > > > > I see what you're saying, but !CONFIG_ARM64_VHE isn't accurate either. The > > > option makes sense if: > > > 1) all cores booted in EL2 > > > == is_hyp_mode_available() > > > 2) ID_AA64MMFR1_EL1.VH=0 or !CONFIG_ARM64_VHE > > > == !is_kernel_in_hyp_mode() > > > > > > The former feels implied for KVM, the latter could be 'Valid if the kernel > > > is running in EL1'? WDYT? > > > > I reckon we can avoid the restriction if we instead add an early stub > > like with have for KASLR. That way we could parse the command line > > early, and if necessary re-initialize EL2 and drop to EL1 before the > > main kernel has to make any decisions about how to initialize things. > > That would allow us to have a more general kvm-arm.mode option where a > > single kernel Image could support: > > > > * "protected" mode on nVHE or VHE HW > > * "nvhe" mode on nVHE or VHE HW > > * "vhe" mode on VHE HW > > > > ... defaulting to VHE/nVHE modes depending on HW support. > > > > That would also be somewhat future-proof if we have to add other > > variants of protected mode in future, as we could extend the mode option > > with parameters for each mode. > > Agreed that 'mode' is a more future-proof flag and I would very much love to > have an option to force nVHE on VHE HW. I however expect that the early stub > would not be a trivial addition and would not want to get into that in this > series. Could we agree on 'protected' as the only supported value for the time > being? Sure, that works for me. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel