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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 31E78C47082 for ; Mon, 7 Jun 2021 18:06:37 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id AE94F60FDA for ; Mon, 7 Jun 2021 18:06:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE94F60FDA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:51626 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lqJdz-0006u8-N5 for qemu-devel@archiver.kernel.org; Mon, 07 Jun 2021 14:06:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36264) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqIw3-0007by-SN for qemu-devel@nongnu.org; Mon, 07 Jun 2021 13:21:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:37334) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lqIw1-0000X3-IS for qemu-devel@nongnu.org; Mon, 07 Jun 2021 13:21:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4ADD76102A; Mon, 7 Jun 2021 17:21:05 +0000 (UTC) Date: Mon, 7 Jun 2021 18:21:02 +0100 From: Catalin Marinas To: Steven Price Subject: Re: [PATCH v14 7/8] KVM: arm64: ioctl to fetch/store tags in a guest Message-ID: <20210607172102.GB17957@arm.com> References: <20210607110816.25762-1-steven.price@arm.com> <20210607110816.25762-8-steven.price@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210607110816.25762-8-steven.price@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Received-SPF: pass client-ip=198.145.29.99; envelope-from=cmarinas@kernel.org; helo=mail.kernel.org X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, 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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Peter Maydell , "Dr. David Alan Gilbert" , Andrew Jones , Haibo Xu , Suzuki K Poulose , qemu-devel@nongnu.org, Marc Zyngier , Juan Quintela , Richard Henderson , linux-kernel@vger.kernel.org, Dave Martin , James Morse , linux-arm-kernel@lists.infradead.org, Thomas Gleixner , Will Deacon , kvmarm@lists.cs.columbia.edu, Julien Thierry Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jun 07, 2021 at 12:08:15PM +0100, Steven Price wrote: > The VMM may not wish to have it's own mapping of guest memory mapped > with PROT_MTE because this causes problems if the VMM has tag checking > enabled (the guest controls the tags in physical RAM and it's unlikely > the tags are correct for the VMM). > > Instead add a new ioctl which allows the VMM to easily read/write the > tags from guest memory, allowing the VMM's mapping to be non-PROT_MTE > while the VMM can still read/write the tags for the purpose of > migration. > > Signed-off-by: Steven Price Reviewed-by: Catalin Marinas