Re: [RFC v2 10/18] guest memory protection: Add guest memory protection interface

From: David Gibson <david@gibson.dropbear.id.au>
To: Greg Kurz <groug@kaod.org>
Cc: qemu-devel@nongnu.org, brijesh.singh@amd.com,
	frankja@linux.ibm.com, dgilbert@redhat.com, pair@us.ibm.com,
	Eduardo Habkost <ehabkost@redhat.com>,
	kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
	cohuck@redhat.com, mdroth@linux.vnet.ibm.com,
	qemu-ppc@nongnu.org,
	Marcel Apfelbaum <marcel.apfelbaum@gmail.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Richard Henderson <rth@twiddle.net>
Subject: Re: [RFC v2 10/18] guest memory protection: Add guest memory protection interface
Date: Wed, 3 Jun 2020 20:09:10 +1000	[thread overview]
Message-ID: <20200603100910.GA11091@umbus.fritz.box> (raw)
In-Reply-To: <20200525122735.1d4a45c7@bahia.lan>

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On Mon, May 25, 2020 at 12:27:35PM +0200, Greg Kurz wrote:
> On Thu, 21 May 2020 13:42:56 +1000
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
> > Several architectures have mechanisms which are designed to protect guest
> > memory from interference or eavesdropping by a compromised hypervisor.  AMD
> > SEV does this with in-chip memory encryption and Intel has a similar
> > mechanism.  POWER's Protected Execution Framework (PEF) accomplishes a
> > similar goal using an ultravisor and new memory protection features,
> > instead of encryption.
> > 
> > This introduces a new GuestMemoryProtection QOM interface which we'll use
> > to (partially) unify handling of these various mechanisms.
> > 
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > ---
> >  backends/Makefile.objs                 |  2 ++
> >  backends/guest-memory-protection.c     | 29 +++++++++++++++++++++
> >  include/exec/guest-memory-protection.h | 36 ++++++++++++++++++++++++++
> >  3 files changed, 67 insertions(+)
> >  create mode 100644 backends/guest-memory-protection.c
> >  create mode 100644 include/exec/guest-memory-protection.h
> > 
> > diff --git a/backends/Makefile.objs b/backends/Makefile.objs
> > index 28a847cd57..e4fb4f5280 100644
> > --- a/backends/Makefile.objs
> > +++ b/backends/Makefile.objs
> > @@ -21,3 +21,5 @@ common-obj-$(CONFIG_LINUX) += hostmem-memfd.o
> >  common-obj-$(CONFIG_GIO) += dbus-vmstate.o
> >  dbus-vmstate.o-cflags = $(GIO_CFLAGS)
> >  dbus-vmstate.o-libs = $(GIO_LIBS)
> > +
> > +common-obj-y += guest-memory-protection.o
> > diff --git a/backends/guest-memory-protection.c b/backends/guest-memory-protection.c
> > new file mode 100644
> > index 0000000000..7e538214f7
> > --- /dev/null
> > +++ b/backends/guest-memory-protection.c
> > @@ -0,0 +1,29 @@
> > +#/*
> > + * QEMU Guest Memory Protection interface
> > + *
> > + * Copyright: David Gibson, Red Hat Inc. 2020
> > + *
> > + * Authors:
> > + *  David Gibson <david@gibson.dropbear.id.au>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * later.  See the COPYING file in the top-level directory.
> > + *
> > + */
> > +
> > +#include "qemu/osdep.h"
> > +
> > +#include "exec/guest-memory-protection.h"
> > +
> > +static const TypeInfo guest_memory_protection_info = {
> > +    .name = TYPE_GUEST_MEMORY_PROTECTION,
> > +    .parent = TYPE_INTERFACE,
> > +    .class_size = sizeof(GuestMemoryProtectionClass),
> > +};
> > +
> > +static void guest_memory_protection_register_types(void)
> > +{
> > +    type_register_static(&guest_memory_protection_info);
> > +}
> > +
> > +type_init(guest_memory_protection_register_types)
> > diff --git a/include/exec/guest-memory-protection.h b/include/exec/guest-memory-protection.h
> > new file mode 100644
> > index 0000000000..38e9b01667
> > --- /dev/null
> > +++ b/include/exec/guest-memory-protection.h
> > @@ -0,0 +1,36 @@
> > +#/*
> > + * QEMU Guest Memory Protection interface
> > + *
> > + * Copyright: David Gibson, Red Hat Inc. 2020
> > + *
> > + * Authors:
> > + *  David Gibson <david@gibson.dropbear.id.au>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > + * later.  See the COPYING file in the top-level directory.
> > + *
> > + */
> > +#ifndef QEMU_GUEST_MEMORY_PROTECTION_H
> > +#define QEMU_GUEST_MEMORY_PROTECTION_H
> > +
> > +#include "qom/object.h"
> > +
> > +typedef struct GuestMemoryProtection GuestMemoryProtection;
> > +
> > +#define TYPE_GUEST_MEMORY_PROTECTION "guest-memory-protection"
> > +#define GUEST_MEMORY_PROTECTION(obj)                                    \
> > +    INTERFACE_CHECK(GuestMemoryProtection, (obj),                       \
> > +                    TYPE_GUEST_MEMORY_PROTECTION)
> > +#define GUEST_MEMORY_PROTECTION_CLASS(klass)                            \
> > +    OBJECT_CLASS_CHECK(GuestMemoryProtectionClass, (klass),             \
> > +                       TYPE_GUEST_MEMORY_PROTECTION)
> > +#define GUEST_MEMORY_PROTECTION_GET_CLASS(obj)                          \
> > +    OBJECT_GET_CLASS(GuestMemoryProtectionClass, (obj),                 \
> > +                     TYPE_GUEST_MEMORY_PROTECTION)
> > +
> > +typedef struct GuestMemoryProtectionClass {
> > +    InterfaceClass parent;
> > +} GuestMemoryProtectionClass;
> > +
> > +#endif /* QEMU_GUEST_MEMORY_PROTECTION_H */
> > +
> 
> Applying patch #1294935 using "git am -s -m"
> Description: [RFC,v2,10/18] guest memory protection: Add guest memory protection
> Applying: guest memory protection: Add guest memory protection interface
> .git/rebase-apply/patch:95: new blank line at EOF.
> +
> warning: 1 line adds whitespace errors.

Oops, fixed.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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