From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 093E2606A31A for ; Tue, 20 Oct 2026 11:06:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BD0QwQIH Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xJ7ca-0002j0-AU; Tue, 20 Oct 2026 07:03:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xJ7cH-0002Zd-14; Tue, 20 Oct 2026 07:02:57 -0400 Received: from sea.source.kernel.org ([172.234.252.31]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xJ7cE-0008TF-Qk; Tue, 20 Oct 2026 07:02:48 -0400 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id DADD0406E9; Tue, 20 Oct 2026 11:02:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 316471F000C4; Tue, 20 Oct 2026 11:02:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792494163; bh=7zYB57edMlEZAvIfqpn2Qe1WGxwqe/dTSl4gWBa2p7A=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=BD0QwQIHT+pwFKbQSnpqFUvGg4/9pbiOjTqNh9V5xSsGWMdwbjbvIrQdPt9ayjkQb HtkLCTgdlJk1+reSP9oucPMxCNj1iy8PXq+9U1Cbap1UJoFUtgcK1FqqoBB0iNvdRL o6uJYi3KRhwmmY+JBCYXdMzXs78vNN1NCAkkB3j0oEuMdmbnQr97jPD4V8RsMw68uk U/J4OvtJDIUoPaxbMs4mtamU6Cf5vLXw/33W/zaY0+3dVGVmCG8kTVptINHrKkdbv9 qt7nOJ2KaOX1ZVMqk79k4nHxBc5d151wEueDkJyxdVLqaBCSs+RIfsejb2Vd/eB3rn S20IKCG4GWteQ== Date: Tue, 20 Oct 2026 13:02:35 +0200 From: Lorenzo Pieralisi To: Mathieu Poirier Cc: Kohei Enju , gshan@redhat.com, michael.roth@amd.com, berrange@redhat.com, kchamart@redhat.com, pierrick.bouvier@oss.qualcomm.com, peter.maydell@linaro.org, mst@redhat.com, cohuck@redhat.com, pbonzini@redhat.com, eblake@redhat.com, armbru@redhat.com, lorenzo.pieralisi@linaro.org, qemu-devel@nongnu.org, qemu-arm@nongnu.org, kvm@vger.kernel.org Subject: Re: [RFC v4 03/24] target/arm: Add confidential guest support Message-ID: References: <20260903193611.1058589-1-mathieu.poirier@linaro.org> <20260903193611.1058589-4-mathieu.poirier@linaro.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=172.234.252.31; envelope-from=lpieralisi@kernel.org; helo=sea.source.kernel.org X-Spam_score_int: -46 X-Spam_score: -4.7 X-Spam_bar: ---- X-Spam_report: (-4.7 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.329, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-arm-bounces+qemu-arm=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-16.1 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_PASS, SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Mon, Oct 19, 2026 at 02:46:10PM -0600, Mathieu Poirier wrote: > On Thu, Sep 24, 2026 at 12:12:35PM +0900, Kohei Enju wrote: > > On 09/22 10:01, Lorenzo Pieralisi wrote: > > > On Tue, Sep 15, 2026 at 04:27:21PM -0500, Michael Roth wrote: > > > > On Thu, Sep 03, 2026 at 01:35:50PM -0600, Mathieu Poirier wrote: > > > > > From: Jean-Philippe Brucker > > > > > > > > > > Add a new RmeGuest object, inheriting from ConfidentialGuestSupport, to > > > > > support the Arm Realm Management Extension (RME). It is instantiated by > > > > > passing on the command-line: > > > > > > > > > > -M virt,confidential-guest-support= > > > > > -object rme-guest,id= > > > > > > > > > > This is only the skeleton. Support will be added in following patches. > > > > > > > > > > Signed-off-by: Jean-Philippe Brucker > > > > > Signed-off-by: Mathieu Poirier > > > > > --- > > > > > docs/system/confidential-guest-support.rst | 1 + > > > > > qapi/qom.json | 13 +++++++ > > > > > target/arm/kvm-rme.c | 42 ++++++++++++++++++++++ > > > > > target/arm/meson.build | 5 ++- > > > > > 4 files changed, 60 insertions(+), 1 deletion(-) > > > > > create mode 100644 target/arm/kvm-rme.c > > > > > > > > > > diff --git a/docs/system/confidential-guest-support.rst b/docs/system/confidential-guest-support.rst > > > > > index 562a7c3c2852..abb56923ad13 100644 > > > > > --- a/docs/system/confidential-guest-support.rst > > > > > +++ b/docs/system/confidential-guest-support.rst > > > > > @@ -42,5 +42,6 @@ Currently supported confidential guest mechanisms are: > > > > > * POWER Protected Execution Facility (PEF) (see :ref:`power-papr-protected-execution-facility-pef`) > > > > > * s390x Protected Virtualization (PV) (see :doc:`s390x/protvirt`) > > > > > * AWS Nitro Enclaves (see :doc:`nitro`) > > > > > +* Arm Realm Management Extension (RME) > > > > > > > > > > Other mechanisms may be supported in future. > > > > > diff --git a/qapi/qom.json b/qapi/qom.json > > > > > index 776b13027fd8..52997c29a32d 100644 > > > > > --- a/qapi/qom.json > > > > > +++ b/qapi/qom.json > > > > > @@ -1288,6 +1288,17 @@ > > > > > 'data': { '*pretty': 'bool', > > > > > '*close-action': 'MonitorQMPCloseAction' } } > > > > > > > > > > +## > > > > > +# @RmeGuestProperties: > > > > > +# > > > > > +# Properties for rme-guest objects. > > > > > +# > > > > > +# Since: 11.1 > > > > > +## > > > > > +{ 'struct': 'RmeGuestProperties', > > > > > + 'base': 'ConfidentialGuestSupportProperties', > > > > > > > > Just FYI, based on input from Markus I'm planning to drop this > > > > ConfidentialGuestSupportProperties base type from my series > > > > since it's probably only SNP/TDX that need to be able to switch > > > > it on/off, whereas this series appears to use/require it from > > > > the start. > > > > > > > > I'm not exactly sure what it will look like for v3 yet, but if you > > > > were based on v2 you'd instead probably just do the following in the > > > > instance_init function for your rme-guest instance: > > > > > > > > cgs->allow_convert_in_place = true; > > > > cgs->convert_in_place = true; > > > > > > > > rather than exposing it as a cmdline option. > > > > > > Yep, it won't be an option for CCA Realms anyway since that will be > > > the baseline. > > > > IIUC, in-place conversion requires RAM backed by a shared/mappable > > guest_memfd. If in-place conversion is always enabled for CCA Realms, > > could QEMU also select the equivalent of > > > > -object memory-backend-guest-memfd,id=ram0,size=...,share=on > > > > automatically for the default RAM, so that specifying the RAM size with > > `-m` is sufficient? > > Are you suggesting that on Arm, we completely get rid of Nit: obviously on Arm rme-guest configs. > -object memory-backend-guest-memfd,id=ram0,size=$(RAMSIZE),share=on If that's what we want to make a default, I guess we ought to override create_default_memdev for arm machines + rme-guest configs ? Pros and cons ? I am not sure how well received is setting implicit defaults for specific machine configs and what that really buys us eventually. > or simply to get rid of "size=$(RAMSIZE)" in the above because it is redundant > with "-m $(RAMSIZE)"? > > Gavin and Michael, what is your take on that suggestion? Yes please any feedback on this is welcome. Thanks, Lorenzo > Thanks, > Mathieu > > > > > Thanks, > > Kohei > > > > > > > > Thanks, > > > Lorenzo > > > > > > > Thanks, > > > > > > > > Mike > > > > > > > > > + 'data': {} } > > > > > + > > > > > ## > > > > > # @ObjectType: > > > > > # > > > > > @@ -1346,6 +1357,7 @@ > > > > > { 'name': 'pr-manager-helper', > > > > > 'if': 'CONFIG_LINUX' }, > > > > > 'qtest', > > > > > + 'rme-guest', > > > > > 'rng-builtin', > > > > > 'rng-egd', > > > > > { 'name': 'rng-random', > > > > > @@ -1427,6 +1439,7 @@ > > > > > 'pr-manager-helper': { 'type': 'PrManagerHelperProperties', > > > > > 'if': 'CONFIG_LINUX' }, > > > > > 'qtest': 'QtestProperties', > > > > > + 'rme-guest': 'RmeGuestProperties', > > > > > 'rng-builtin': 'RngProperties', > > > > > 'rng-egd': 'RngEgdProperties', > > > > > 'rng-random': { 'type': 'RngRandomProperties', > > > > > diff --git a/target/arm/kvm-rme.c b/target/arm/kvm-rme.c > > > > > new file mode 100644 > > > > > index 000000000000..42e1d1e7b859 > > > > > --- /dev/null > > > > > +++ b/target/arm/kvm-rme.c > > > > > @@ -0,0 +1,42 @@ > > > > > +/* > > > > > + * QEMU Arm RME support > > > > > + * > > > > > + * SPDX-License-Identifier: GPL-2.0-or-later > > > > > + * > > > > > + * Copyright Linaro 2026 > > > > > + */ > > > > > + > > > > > +#include "qemu/osdep.h" > > > > > + > > > > > +#include "hw/core/boards.h" > > > > > +#include "hw/core/cpu.h" > > > > > +#include "kvm_arm.h" > > > > > +#include "migration/blocker.h" > > > > > +#include "qapi/error.h" > > > > > +#include "qom/object_interfaces.h" > > > > > +#include "system/confidential-guest-support.h" > > > > > +#include "system/kvm.h" > > > > > +#include "system/runstate.h" > > > > > + > > > > > +#define TYPE_RME_GUEST "rme-guest" > > > > > +OBJECT_DECLARE_SIMPLE_TYPE(RmeGuest, RME_GUEST) > > > > > + > > > > > +struct RmeGuest { > > > > > + ConfidentialGuestSupport parent_obj; > > > > > +}; > > > > > + > > > > > +OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(RmeGuest, rme_guest, RME_GUEST, > > > > > + CONFIDENTIAL_GUEST_SUPPORT, > > > > > + { TYPE_USER_CREATABLE }, { }) > > > > > + > > > > > +static void rme_guest_class_init(ObjectClass *oc, const void *data) > > > > > +{ > > > > > +} > > > > > + > > > > > +static void rme_guest_init(Object *obj) > > > > > +{ > > > > > +} > > > > > + > > > > > +static void rme_guest_finalize(Object *obj) > > > > > +{ > > > > > +} > > > > > diff --git a/target/arm/meson.build b/target/arm/meson.build > > > > > index 0369f96b4cc6..9d322a7aad28 100644 > > > > > --- a/target/arm/meson.build > > > > > +++ b/target/arm/meson.build > > > > > @@ -31,7 +31,10 @@ arm_common_user_system_ss.add(when: 'TARGET_AARCH64', if_true: files( > > > > > arm_common_system_ss.add(files( > > > > > 'arm-qmp-cmds.c', > > > > > )) > > > > > -arm_system_ss.add(when: 'CONFIG_KVM', if_true: files('hyp_gdbstub.c', 'kvm.c')) > > > > > +arm_system_ss.add(when: 'CONFIG_KVM', if_true: files( > > > > > + 'hyp_gdbstub.c', > > > > > + 'kvm.c', > > > > > + 'kvm-rme.c')) > > > > > arm_system_ss.add(when: 'CONFIG_HVF', if_true: files('hyp_gdbstub.c')) > > > > > > > > > > arm_user_ss.add(files('cpu.c')) > > > > > -- > > > > > 2.43.0 > > > > > > > > > >