@@ -25,8 +25,8 @@ support for notifying a guest's operating system when certain types of VMEXITs
are about to occur. This allows the guest to selectively share information with
the hypervisor to satisfy the requested function.
-Launching
----------
+Launching (SEV and SEV-ES)
+--------------------------
Boot images (such as bios) must be encrypted before a guest can be booted. The
``MEMORY_ENCRYPT_OP`` ioctl provides commands to encrypt the images: ``LAUNCH_START``,
@@ -161,6 +161,72 @@ The value of GCTX.LD is
If kernel hashes are not used, or SEV-ES is disabled, use empty blobs for
``kernel_hashes_blob`` and ``vmsas_blob`` as needed.
+Launching (SEV-SNP)
+-------------------
+Boot images (such as bios) must be encrypted before a guest can be booted. The
+``MEMORY_ENCRYPT_OP`` ioctl provides commands to encrypt the images:
+``SNP_LAUNCH_START``, ``SNP_LAUNCH_UPDATE``, and ``SNP_LAUNCH_FINISH``. These
+three commands communicate with SEV-SNP firmware to generate a fresh memory
+encryption key for the VM, encrypt the boot images for a successful launch. For
+more details on the SEV-SNP firmware interfaces used by these commands please
+see the SEV-SNP Firmware ABI.
+
+``SNP_LAUNCH_START`` is called first to create a cryptographic launch context
+within the firmware. To create this context, the guest owner must provide a
+guest policy and other parameters as described in the SEV-SNP firmware
+specification. The launch parameters should be specified as described in the
+QAPI schema for the sev-snp-guest object.
+
+The ``SNP_LAUNCH_START`` uses the following parameters, which can be configured
+by the corresponding parameters documented in the QAPI schema for the
+'sev-snp-guest' object.
+
++--------+-------+----------+-------------------------------------------------+
+| key | type | default | meaning |
++---------------------------+-------------------------------------------------+
+| policy | hex | 0x30000 | a 64-bit guest policy |
++---------------------------+-------------------------------------------------+
+| guest-visible-workarounds | string| 0 | 16-byte base64 encoded string|
+| | | | for guest OS visible |
+| | | | workarounds. |
++---------------------------+-------------------------------------------------+
+
+``SNP_LAUNCH_UPDATE`` encrypts the memory region using the cryptographic context
+created via the ``SNP_LAUNCH_START`` command. If required, this command can be
+called multiple times to encrypt different memory regions. The command also
+calculates the measurement of the memory contents as it encrypts.
+
+``SNP_LAUNCH_FINISH`` finalizes the guest launch flow. Optionally, while
+finalizing the launch the firmware can perform checks on the launch digest
+computing through the ``SNP_LAUNCH_UPDATE``. To perform the check the user must
+supply the id block, authentication blob and host data that should be included
+in the attestation report. See the SEV-SNP spec for further details.
+
+The ``SNP_LAUNCH_FINISH`` uses the following parameters, which can be configured
+by the corresponding parameters documented in the QAPI schema for the
+'sev-snp-guest' object.
+
++--------------------+-------+----------+-------------------------------------+
+| key | type | default | meaning |
++--------------------+-------+----------+-------------------------------------+
+| id-block | string| none | base64 encoded ID block |
++--------------------+-------+----------+-------------------------------------+
+| id-auth | string| none | base64 encoded authentication |
+| | | | information |
++--------------------+-------+----------+-------------------------------------+
+| author-key-enabled | bool | 0 | auth block contains author key |
++--------------------+-------+----------+-------------------------------------+
+| host_data | string| none | host provided data |
++--------------------+-------+----------+-------------------------------------+
+
+To launch a SEV-SNP guest (additional parameters are documented in the QAPI
+schema for the 'sev-snp-guest' object)::
+
+ # ${QEMU} \
+ -machine ...,confidential-guest-support=sev0 \
+ -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1
+
+
Debugging
---------
@@ -929,6 +929,62 @@
'*handle': 'uint32',
'*legacy-vm-type': 'bool' } }
+##
+# @SevSnpGuestProperties:
+#
+# Properties for sev-snp-guest objects. Most of these are direct
+# arguments for the KVM_SNP_* interfaces documented in the Linux
+# kernel source under
+# Documentation/arch/x86/amd-memory-encryption.rst, which are in turn
+# closely coupled with the SNP_INIT/SNP_LAUNCH_* firmware commands
+# documented in the SEV-SNP Firmware ABI Specification (Rev 0.9).
+#
+# More usage information is also available in the QEMU source tree
+# under docs/amd-memory-encryption.
+#
+# @policy: the 'POLICY' parameter to the SNP_LAUNCH_START command, as
+# defined in the SEV-SNP firmware ABI (default: 0x30000)
+#
+# @guest-visible-workarounds: 16-byte, base64-encoded blob to report
+# hypervisor-defined workarounds, corresponding to the 'GOSVW'
+# parameter of the SNP_LAUNCH_START command defined in the SEV-SNP
+# firmware ABI (default: all-zero)
+#
+# @id-block: 96-byte, base64-encoded blob to provide the 'ID Block'
+# structure for the SNP_LAUNCH_FINISH command defined in the
+# SEV-SNP firmware ABI (default: all-zero)
+#
+# @id-auth: 4096-byte, base64-encoded blob to provide the 'ID
+# Authentication Information Structure' for the SNP_LAUNCH_FINISH
+# command defined in the SEV-SNP firmware ABI (default: all-zero)
+#
+# @author-key-enabled: true if 'id-auth' blob contains the 'AUTHOR_KEY'
+# field defined SEV-SNP firmware ABI (default: false)
+#
+# @host-data: 32-byte, base64-encoded, user-defined blob to provide to
+# the guest, as documented for the 'HOST_DATA' parameter of the
+# SNP_LAUNCH_FINISH command in the SEV-SNP firmware ABI (default:
+# all-zero)
+#
+# @vcek-disabled: Guests are by default allowed to choose between VLEK
+# (Versioned Loaded Endorsement Key) or VCEK (Versioned Chip
+# Endorsement Key) when requesting attestation reports from
+# firmware. Set this to true to disable the use of VCEK.
+# (default: false) (since: 9.1)
+#
+# Since: 9.1
+##
+{ 'struct': 'SevSnpGuestProperties',
+ 'base': 'SevCommonProperties',
+ 'data': {
+ '*policy': 'uint64',
+ '*guest-visible-workarounds': 'str',
+ '*id-block': 'str',
+ '*id-auth': 'str',
+ '*author-key-enabled': 'bool',
+ '*host-data': 'str',
+ '*vcek-disabled': 'bool' } }
+
##
# @ThreadContextProperties:
#
@@ -1007,6 +1063,7 @@
{ 'name': 'secret_keyring',
'if': 'CONFIG_SECRET_KEYRING' },
'sev-guest',
+ 'sev-snp-guest',
'thread-context',
's390-pv-guest',
'throttle-group',
@@ -1077,6 +1134,7 @@
'secret_keyring': { 'type': 'SecretKeyringProperties',
'if': 'CONFIG_SECRET_KEYRING' },
'sev-guest': 'SevGuestProperties',
+ 'sev-snp-guest': 'SevSnpGuestProperties',
'thread-context': 'ThreadContextProperties',
'throttle-group': 'ThrottleGroupProperties',
'tls-creds-anon': 'TlsCredsAnonProperties',
@@ -22,6 +22,7 @@
#define TYPE_SEV_COMMON "sev-common"
#define TYPE_SEV_GUEST "sev-guest"
+#define TYPE_SEV_SNP_GUEST "sev-snp-guest"
#define SEV_POLICY_NODBG 0x1
#define SEV_POLICY_NOKS 0x2
@@ -42,6 +42,7 @@
OBJECT_DECLARE_TYPE(SevCommonState, SevCommonStateClass, SEV_COMMON)
OBJECT_DECLARE_TYPE(SevGuestState, SevCommonStateClass, SEV_GUEST)
+OBJECT_DECLARE_TYPE(SevSnpGuestState, SevCommonStateClass, SEV_SNP_GUEST)
struct SevCommonState {
X86ConfidentialGuest parent_obj;
@@ -96,8 +97,22 @@ struct SevGuestState {
bool legacy_vm_type;
};
+struct SevSnpGuestState {
+ SevCommonState parent_obj;
+
+ /* configuration parameters */
+ char *guest_visible_workarounds;
+ char *id_block;
+ char *id_auth;
+ char *host_data;
+
+ struct kvm_sev_snp_launch_start kvm_start_conf;
+ struct kvm_sev_snp_launch_finish kvm_finish_conf;
+};
+
#define DEFAULT_GUEST_POLICY 0x1 /* disable debug */
#define DEFAULT_SEV_DEVICE "/dev/sev"
+#define DEFAULT_SEV_SNP_POLICY 0x30000
#define SEV_INFO_BLOCK_GUID "00f771de-1a7e-4fcb-890e-68c77e2fb44e"
typedef struct __attribute__((__packed__)) SevInfoBlock {
@@ -1500,11 +1515,249 @@ static const TypeInfo sev_guest_info = {
.class_init = sev_guest_class_init,
};
+static void
+sev_snp_guest_get_policy(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ visit_type_uint64(v, name,
+ (uint64_t *)&SEV_SNP_GUEST(obj)->kvm_start_conf.policy,
+ errp);
+}
+
+static void
+sev_snp_guest_set_policy(Object *obj, Visitor *v, const char *name,
+ void *opaque, Error **errp)
+{
+ visit_type_uint64(v, name,
+ (uint64_t *)&SEV_SNP_GUEST(obj)->kvm_start_conf.policy,
+ errp);
+}
+
+static char *
+sev_snp_guest_get_guest_visible_workarounds(Object *obj, Error **errp)
+{
+ return g_strdup(SEV_SNP_GUEST(obj)->guest_visible_workarounds);
+}
+
+static void
+sev_snp_guest_set_guest_visible_workarounds(Object *obj, const char *value,
+ Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+ struct kvm_sev_snp_launch_start *start = &sev_snp_guest->kvm_start_conf;
+ g_autofree guchar *blob;
+ gsize len;
+
+ g_free(sev_snp_guest->guest_visible_workarounds);
+
+ /* store the base64 str so we don't need to re-encode in getter */
+ sev_snp_guest->guest_visible_workarounds = g_strdup(value);
+
+ blob = qbase64_decode(sev_snp_guest->guest_visible_workarounds,
+ -1, &len, errp);
+ if (!blob) {
+ return;
+ }
+
+ if (len != sizeof(start->gosvw)) {
+ error_setg(errp, "parameter length of %lu exceeds max of %lu",
+ len, sizeof(start->gosvw));
+ return;
+ }
+
+ memcpy(start->gosvw, blob, len);
+}
+
+static char *
+sev_snp_guest_get_id_block(Object *obj, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ return g_strdup(sev_snp_guest->id_block);
+}
+
+static void
+sev_snp_guest_set_id_block(Object *obj, const char *value, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+ struct kvm_sev_snp_launch_finish *finish = &sev_snp_guest->kvm_finish_conf;
+ gsize len;
+
+ g_free(sev_snp_guest->id_block);
+ g_free((guchar *)finish->id_block_uaddr);
+
+ /* store the base64 str so we don't need to re-encode in getter */
+ sev_snp_guest->id_block = g_strdup(value);
+
+ finish->id_block_uaddr =
+ (uint64_t)qbase64_decode(sev_snp_guest->id_block, -1, &len, errp);
+
+ if (!finish->id_block_uaddr) {
+ return;
+ }
+
+ if (len != KVM_SEV_SNP_ID_BLOCK_SIZE) {
+ error_setg(errp, "parameter length of %lu not equal to %u",
+ len, KVM_SEV_SNP_ID_BLOCK_SIZE);
+ return;
+ }
+
+ finish->id_block_en = (len) ? 1 : 0;
+}
+
+static char *
+sev_snp_guest_get_id_auth(Object *obj, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ return g_strdup(sev_snp_guest->id_auth);
+}
+
+static void
+sev_snp_guest_set_id_auth(Object *obj, const char *value, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+ struct kvm_sev_snp_launch_finish *finish = &sev_snp_guest->kvm_finish_conf;
+ gsize len;
+
+ g_free(sev_snp_guest->id_auth);
+ g_free((guchar *)finish->id_auth_uaddr);
+
+ /* store the base64 str so we don't need to re-encode in getter */
+ sev_snp_guest->id_auth = g_strdup(value);
+
+ finish->id_auth_uaddr =
+ (uint64_t)qbase64_decode(sev_snp_guest->id_auth, -1, &len, errp);
+
+ if (!finish->id_auth_uaddr) {
+ return;
+ }
+
+ if (len > KVM_SEV_SNP_ID_AUTH_SIZE) {
+ error_setg(errp, "parameter length:ID_AUTH %lu exceeds max of %u",
+ len, KVM_SEV_SNP_ID_AUTH_SIZE);
+ return;
+ }
+}
+
+static bool
+sev_snp_guest_get_author_key_enabled(Object *obj, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ return !!sev_snp_guest->kvm_finish_conf.auth_key_en;
+}
+
+static void
+sev_snp_guest_set_author_key_enabled(Object *obj, bool value, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ sev_snp_guest->kvm_finish_conf.auth_key_en = value;
+}
+
+static bool
+sev_snp_guest_get_vcek_disabled(Object *obj, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ return !!sev_snp_guest->kvm_finish_conf.vcek_disabled;
+}
+
+static void
+sev_snp_guest_set_vcek_disabled(Object *obj, bool value, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ sev_snp_guest->kvm_finish_conf.vcek_disabled = value;
+}
+
+static char *
+sev_snp_guest_get_host_data(Object *obj, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ return g_strdup(sev_snp_guest->host_data);
+}
+
+static void
+sev_snp_guest_set_host_data(Object *obj, const char *value, Error **errp)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+ struct kvm_sev_snp_launch_finish *finish = &sev_snp_guest->kvm_finish_conf;
+ g_autofree guchar *blob;
+ gsize len;
+
+ g_free(sev_snp_guest->host_data);
+
+ /* store the base64 str so we don't need to re-encode in getter */
+ sev_snp_guest->host_data = g_strdup(value);
+
+ blob = qbase64_decode(sev_snp_guest->host_data, -1, &len, errp);
+
+ if (!blob) {
+ return;
+ }
+
+ if (len != sizeof(finish->host_data)) {
+ error_setg(errp, "parameter length of %lu not equal to %lu",
+ len, sizeof(finish->host_data));
+ return;
+ }
+
+ memcpy(finish->host_data, blob, len);
+}
+
+static void
+sev_snp_guest_class_init(ObjectClass *oc, void *data)
+{
+ object_class_property_add(oc, "policy", "uint64",
+ sev_snp_guest_get_policy,
+ sev_snp_guest_set_policy, NULL, NULL);
+ object_class_property_add_str(oc, "guest-visible-workarounds",
+ sev_snp_guest_get_guest_visible_workarounds,
+ sev_snp_guest_set_guest_visible_workarounds);
+ object_class_property_add_str(oc, "id-block",
+ sev_snp_guest_get_id_block,
+ sev_snp_guest_set_id_block);
+ object_class_property_add_str(oc, "id-auth",
+ sev_snp_guest_get_id_auth,
+ sev_snp_guest_set_id_auth);
+ object_class_property_add_bool(oc, "author-key-enabled",
+ sev_snp_guest_get_author_key_enabled,
+ sev_snp_guest_set_author_key_enabled);
+ object_class_property_add_bool(oc, "vcek-required",
+ sev_snp_guest_get_vcek_disabled,
+ sev_snp_guest_set_vcek_disabled);
+ object_class_property_add_str(oc, "host-data",
+ sev_snp_guest_get_host_data,
+ sev_snp_guest_set_host_data);
+}
+
+static void
+sev_snp_guest_instance_init(Object *obj)
+{
+ SevSnpGuestState *sev_snp_guest = SEV_SNP_GUEST(obj);
+
+ /* default init/start/finish params for kvm */
+ sev_snp_guest->kvm_start_conf.policy = DEFAULT_SEV_SNP_POLICY;
+}
+
+/* guest info specific to sev-snp */
+static const TypeInfo sev_snp_guest_info = {
+ .parent = TYPE_SEV_COMMON,
+ .name = TYPE_SEV_SNP_GUEST,
+ .instance_size = sizeof(SevSnpGuestState),
+ .class_init = sev_snp_guest_class_init,
+ .instance_init = sev_snp_guest_instance_init,
+};
+
static void
sev_register_types(void)
{
type_register_static(&sev_common_info);
type_register_static(&sev_guest_info);
+ type_register_static(&sev_snp_guest_info);
}
type_init(sev_register_types);