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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 5847CC2D0E4 for ; Mon, 23 Nov 2020 12:17:09 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 9E9A220781 for ; Mon, 23 Nov 2020 12:17:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="IjfC1FxE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E9A220781 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C7E184B761; Mon, 23 Nov 2020 07:17:07 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@redhat.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id d3mANfx-FhiO; Mon, 23 Nov 2020 07:17:06 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id CA4254B779; Mon, 23 Nov 2020 07:17:06 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id A604D4B761 for ; Mon, 23 Nov 2020 07:17:05 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6ILp+97p36n4 for ; Mon, 23 Nov 2020 07:17:04 -0500 (EST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 685534B75D for ; Mon, 23 Nov 2020 07:17:04 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1606133824; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=RSa6axA8acXlN/nHzWzCr89Oo5Z355MEuIWkDZmMlas=; b=IjfC1FxEKllYzNvQ5QYpN0juH2PKxW9EmLUkifZQXQRp33nV59sKERus6qyWwx99cRWkd5 IRWLEgGqq3vmpDOZrcqOAUehKnV5L+nUf3D1L8U2HEDA6n5lng7e6b9N4+7iD5tLaybv7G URbJMaHm3tfbxhWKn2yhkypNRCIYYt4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-446-OjmxZbq0PEacCG4qpdCK8w-1; Mon, 23 Nov 2020 07:16:20 -0500 X-MC-Unique: OjmxZbq0PEacCG4qpdCK8w-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CBE4A8AEA40; Mon, 23 Nov 2020 12:16:17 +0000 (UTC) Received: from work-vm (ovpn-114-158.ams2.redhat.com [10.36.114.158]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CC31B5D9CC; Mon, 23 Nov 2020 12:16:13 +0000 (UTC) Date: Mon, 23 Nov 2020 12:16:11 +0000 From: "Dr. David Alan Gilbert" To: Peter Maydell Subject: Re: [PATCH v5 0/2] MTE support for KVM guest Message-ID: <20201123121611.GG3022@work-vm> References: <20201119153901.53705-1-steven.price@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Cc: QEMU Developers , Catalin Marinas , Juan Quintela , Richard Henderson , lkml - Kernel Mailing List , Steven Price , arm-mail-list , Marc Zyngier , Thomas Gleixner , Will Deacon , kvmarm , Dave Martin X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu * Peter Maydell (peter.maydell@linaro.org) wrote: > On Thu, 19 Nov 2020 at 15:39, Steven Price wrote: > > This series adds support for Arm's Memory Tagging Extension (MTE) to > > KVM, allowing KVM guests to make use of it. This builds on the existing > > user space support already in v5.10-rc1, see [1] for an overview. > > > The change to require the VMM to map all guest memory PROT_MTE is > > significant as it means that the VMM has to deal with the MTE tags even > > if it doesn't care about them (e.g. for virtual devices or if the VMM > > doesn't support migration). Also unfortunately because the VMM can > > change the memory layout at any time the check for PROT_MTE/VM_MTE has > > to be done very late (at the point of faulting pages into stage 2). > > I'm a bit dubious about requring the VMM to map the guest memory > PROT_MTE unless somebody's done at least a sketch of the design > for how this would work on the QEMU side. Currently QEMU just > assumes the guest memory is guest memory and it can access it > without special precautions... Although that is also changing because of the encrypted/protected memory in things like SEV. Dave > thanks > -- PMM > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm