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 <[email protected]>
> > > >
> > > > 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=<id>
> > > > -object rme-guest,id=<id>
> > > >
> > > > This is only the skeleton. Support will be added in following patches.
> > > >
> > > > Signed-off-by: Jean-Philippe Brucker <[email protected]>
> > > > Signed-off-by: Mathieu Poirier <[email protected]>
> > > > ---
> > > > 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?
>
I'm almost done crafting a new revision that will be based on V20 of the KVM
patchset. I will look into your request for the revision after this one.
> 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
> > > >
> > > >
