qemu/include/exec/confidential-guest-support.h
Paolo Bonzini dc0d28ca46 machine: allow early use of machine_require_guest_memfd
Ask the ConfidentialGuestSupport object whether to use guest_memfd
for KVM-backend private memory.  This bool can be set in instance_init
(or user_complete) so that it is available when the machine is created.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-05 11:01:06 +02:00

100 lines
3.1 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_TYPE(ConfidentialGuestSupport,
ConfidentialGuestSupportClass,
CONFIDENTIAL_GUEST_SUPPORT)
struct ConfidentialGuestSupport {
Object parent;
/*
* True if the machine should use guest_memfd for RAM.
*/
bool require_guest_memfd;
/*
* 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;
int (*kvm_init)(ConfidentialGuestSupport *cgs, Error **errp);
int (*kvm_reset)(ConfidentialGuestSupport *cgs, Error **errp);
} ConfidentialGuestSupportClass;
static inline int confidential_guest_kvm_init(ConfidentialGuestSupport *cgs,
Error **errp)
{
ConfidentialGuestSupportClass *klass;
klass = CONFIDENTIAL_GUEST_SUPPORT_GET_CLASS(cgs);
if (klass->kvm_init) {
return klass->kvm_init(cgs, errp);
}
return 0;
}
static inline int confidential_guest_kvm_reset(ConfidentialGuestSupport *cgs,
Error **errp)
{
ConfidentialGuestSupportClass *klass;
klass = CONFIDENTIAL_GUEST_SUPPORT_GET_CLASS(cgs);
if (klass->kvm_reset) {
return klass->kvm_reset(cgs, errp);
}
return 0;
}
#endif /* !CONFIG_USER_ONLY */
#endif /* QEMU_CONFIDENTIAL_GUEST_SUPPORT_H */