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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 91179C4361B for ; Tue, 15 Dec 2020 11:47:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4C4D222209 for ; Tue, 15 Dec 2020 11:47:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728815AbgLOLrU (ORCPT ); Tue, 15 Dec 2020 06:47:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24617 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728802AbgLOLrO (ORCPT ); Tue, 15 Dec 2020 06:47:14 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608032748; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ldS1J7wGI5856oRlyFwiQvFcG4BV7UZaA4YAKir6cWo=; b=fhjLoBq9DQTXhecOH+BAY6+rObD0sAiI+rgTYcz9R/sEkisNMPjR2BqMxKgidoEQJ1WnMo pk9aPI119N38w5MXXL6Ke456QeGtSbsIfDqXDzKzuFannkVVwYGLEBjdri0qO95cLNJQX0 vEIMcP0/U3yp3WJ63B7jZ4XXoVo6tSY= 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-586-r2-c6gfyPh-q2Lyxb7nHrw-1; Tue, 15 Dec 2020 06:45:44 -0500 X-MC-Unique: r2-c6gfyPh-q2Lyxb7nHrw-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 781A510054FF; Tue, 15 Dec 2020 11:45:42 +0000 (UTC) Received: from gondolin (ovpn-114-220.ams2.redhat.com [10.36.114.220]) by smtp.corp.redhat.com (Postfix) with ESMTP id CCC9D5D9CA; Tue, 15 Dec 2020 11:45:29 +0000 (UTC) Date: Tue, 15 Dec 2020 12:45:26 +0100 From: Cornelia Huck To: David Gibson Cc: pair@us.ibm.com, pbonzini@redhat.com, frankja@linux.ibm.com, brijesh.singh@amd.com, dgilbert@redhat.com, qemu-devel@nongnu.org, Eduardo Habkost , qemu-ppc@nongnu.org, rth@twiddle.net, thuth@redhat.com, berrange@redhat.com, mdroth@linux.vnet.ibm.com, Marcelo Tosatti , "Michael S. Tsirkin" , Marcel Apfelbaum , david@redhat.com, Richard Henderson , borntraeger@de.ibm.com, kvm@vger.kernel.org, qemu-s390x@nongnu.org, pasic@linux.ibm.com Subject: Re: [for-6.0 v5 13/13] s390: Recognize securable-guest-memory option Message-ID: <20201215124526.7c33dc8d.cohuck@redhat.com> In-Reply-To: <20201204054415.579042-14-david@gibson.dropbear.id.au> References: <20201204054415.579042-1-david@gibson.dropbear.id.au> <20201204054415.579042-14-david@gibson.dropbear.id.au> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, 4 Dec 2020 16:44:15 +1100 David Gibson wrote: > At least some s390 cpu models support "Protected Virtualization" (PV), > a mechanism to protect guests from eavesdropping by a compromised > hypervisor. > > This is similar in function to other mechanisms like AMD's SEV and > POWER's PEF, which are controlled bythe "securable-guest-memory" machine s/bythe/by the/ > option. s390 is a slightly special case, because we already supported > PV, simply by using a CPU model with the required feature > (S390_FEAT_UNPACK). > > To integrate this with the option used by other platforms, we > implement the following compromise: > > - When the securable-guest-memory option is set, s390 will recognize it, > verify that the CPU can support PV (failing if not) and set virtio > default options necessary for encrypted or protected guests, as on > other platforms. i.e. if securable-guest-memory is set, we will > either create a guest capable of entering PV mode, or fail outright s/outright/outright./ > > - If securable-guest-memory is not set, guest's might still be able to s/guest's/guests/ > enter PV mode, if the CPU has the right model. This may be a > little surprising, but shouldn't actually be harmful. > > To start a guest supporting Protected Virtualization using the new > option use the command line arguments: > -object s390-pv-guest,id=pv0 -machine securable-guest-memory=pv0 > > Signed-off-by: David Gibson > --- > hw/s390x/pv.c | 58 +++++++++++++++++++++++++++++++++++++++++++ > include/hw/s390x/pv.h | 1 + > target/s390x/kvm.c | 3 +++ > 3 files changed, 62 insertions(+) > Modulo any naming changes etc., I think this should work for s390. I don't have the hardware to test this, however, and would appreciate someone with a PV setup giving this a go.