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 phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 70D21C636CC for ; Tue, 7 Feb 2023 16:35:36 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id DE18A85E2E; Tue, 7 Feb 2023 17:35:33 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="pNj6NWj6"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 404DE85E38; Tue, 7 Feb 2023 17:35:32 +0100 (CET) Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id E13BB85E0A for ; Tue, 7 Feb 2023 17:35:29 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=maz@kernel.org 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 8A185B81A03; Tue, 7 Feb 2023 16:35:29 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42D4AC433D2; Tue, 7 Feb 2023 16:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675787728; bh=XgMDEk9mhkF4wZoKp6+ec/9p0Kvidett5uyEXlmkjcQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=pNj6NWj6WojHzKtWSTO+YfuLjQQXCB64v10gWSSkHAwySIl8ZOIJCLRnYUDFc5Vgk c/FFaeCkJiIOXisXmcByyzxdFinNk8vVGE4PRl++WhoWdeKxWDTAQFf+vjCycR5Dcr uGvF07NnDmzTgx9Gu56hKvUuUu8PZ17ZUxYxiEvXMNqFjBK2cw1p0hSBnfTP46oVyj kIUFJ1QAfQm/5bTjFKFXwbhCp+XnrmeooG/Q0ex0Kb85MLf90Vy4r+ETuhPXXXBOlR GYqnOOehCipL/UTH24QYfOb350NCKBwS34uluuW3xddCTDoibopn7EjCljlVFZlSpT Nz5C9ZEP5AN0Q== Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1pPQwH-008Q0M-Ur; Tue, 07 Feb 2023 16:35:26 +0000 MIME-Version: 1.0 Date: Tue, 07 Feb 2023 16:35:25 +0000 From: Marc Zyngier To: "Ying-Chun Liu (PaulLiu)" Cc: u-boot@lists.denx.de, Will Deacon , Tom Rini Subject: Re: [PATCH 1/2] arm: cpu: Add optional CMOs by VA In-Reply-To: <20230207162014.58664-2-paul.liu@linaro.org> References: <20230207162014.58664-1-paul.liu@linaro.org> <20230207162014.58664-2-paul.liu@linaro.org> User-Agent: Roundcube Webmail/1.4.13 Message-ID: <0acfdc333e22249784b4abd63d8d09e6@kernel.org> X-Sender: maz@kernel.org Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: paul.liu@linaro.org, u-boot@lists.denx.de, willdeacon@google.com, trini@konsulko.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean On 2023-02-07 16:20, Ying-Chun Liu (PaulLiu) wrote: > Exposing set/way cache maintenance to a virtual machine is unsafe, not > least because the instructions are not permission-checked but also > because they are not broadcast between CPUs. Consequently, KVM traps > and > emulates such maintenance in the host kernel using by-VA operations and > looping over the stage-2 page-tables. However, when running under > protected KVM, these instructions are not able to be emulated and will > instead result in an exception being delivered to the guest. > > Introduce CONFIG_CMO_BY_VA_ONLY so that virtual platforms can select > this option and perform by-VA cache maintenance instead of using the > set/way instructions. > > Signed-off-by: Ying-Chun Liu (PaulLiu) > Signed-off-by: Marc Zyngier > Signed-off-by: Will Deacon > Cc: Tom Rini The sign-off chain looks pretty odd. Either you are the author of this patch, and I have nothing to do on the sign-off list, or I'm the author and the authorship is wrong. Similar things would apply for Will. So which one is it? M. -- Jazz is not dead. It just smells funny...