xemu/include/exec/confidential-guest-support.h
David Gibson abc27d4241 confidential guest support: Introduce cgs "ready" flag
The platform specific details of mechanisms for implementing
confidential guest support may require setup at various points during
initialization.  Thus, it's not really feasible to have a single cgs
initialization hook, but instead each mechanism needs its own
initialization calls in arch or machine specific code.

However, to make it harder to have a bug where a mechanism isn't
properly initialized under some circumstances, we want to have a
common place, late in boot, where we verify that cgs has been
initialized if it was requested.

This patch introduces a ready flag to the ConfidentialGuestSupport
base type to accomplish this, which we verify in
qemu_machine_creation_done().

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
2021-02-08 16:57:38 +11:00

63 lines
2.2 KiB
C

/*
* QEMU Confidential Guest support
* This interface describes the common pieces between various
* schemes for protecting guest memory or other state against a
* compromised hypervisor. This includes memory encryption (AMD's
* SEV and Intel's MKTME) or special protection modes (PEF on POWER,
* or PV on s390x).
*
* Copyright Red Hat.
*
* 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_CONFIDENTIAL_GUEST_SUPPORT_H
#define QEMU_CONFIDENTIAL_GUEST_SUPPORT_H
#ifndef CONFIG_USER_ONLY
#include "qom/object.h"
#define TYPE_CONFIDENTIAL_GUEST_SUPPORT "confidential-guest-support"
OBJECT_DECLARE_SIMPLE_TYPE(ConfidentialGuestSupport, CONFIDENTIAL_GUEST_SUPPORT)
struct ConfidentialGuestSupport {
Object parent;
/*
* ready: flag set by CGS initialization code once it's ready to
* start executing instructions in a potentially-secure
* guest
*
* The definition here is a bit fuzzy, because this is essentially
* part of a self-sanity-check, rather than a strict mechanism.
*
* It's not feasible to have a single point in the common machine
* init path to configure confidential guest support, because
* different mechanisms have different interdependencies requiring
* initialization in different places, often in arch or machine
* type specific code. It's also usually not possible to check
* for invalid configurations until that initialization code.
* That means it would be very easy to have a bug allowing CGS
* init to be bypassed entirely in certain configurations.
*
* Silently ignoring a requested security feature would be bad, so
* to avoid that we check late in init that this 'ready' flag is
* set if CGS was requested. If the CGS init hasn't happened, and
* so 'ready' is not set, we'll abort.
*/
bool ready;
};
typedef struct ConfidentialGuestSupportClass {
ObjectClass parent;
} ConfidentialGuestSupportClass;
#endif /* !CONFIG_USER_ONLY */
#endif /* QEMU_CONFIDENTIAL_GUEST_SUPPORT_H */