[PATCH v6 14/60] i386/tdx: Support user configurable mrconfigid/mrowner/mrownerconfig

Xiaoyao Li
2024-11-05T06:37:22Z

From: Isaku Yamahata <isaku.yamahata@intel.com>

Three sha384 hash values, mrconfigid, mrowner and mrownerconfig, of a TD
can be provided for TDX attestation. Detailed meaning of them can be
found: https://lore.kernel.org/qemu-devel/31d6dbc1-f453-4cef-ab08-4813f4e0ff92@intel.com/

Allow user to specify those values via property mrconfigid, mrowner and
mrownerconfig. They are all in base64 format.

example
-object tdx-guest, \
mrconfigid=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\
mrowner=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\
mrownerconfig=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Co-developed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
Changes in v6:
- refine the doc comment of QAPI properties;

Changes in v5:
- refine the description of QAPI properties and add description of
default value when not specified;

Changes in v4:
- describe more of there fields in qom.json
- free the old value before set new value to avoid memory leak in
_setter(); (Daniel)

Changes in v3:
- use base64 encoding instread of hex-string;
---
qapi/qom.json | 16 +++++++-
target/i386/kvm/tdx.c | 86 +++++++++++++++++++++++++++++++++++++++++++
target/i386/kvm/tdx.h | 3 ++
3 files changed, 104 insertions(+), 1 deletion(-)

diff --git a/qapi/qom.json b/qapi/qom.json
index b3dc0cfa2641..477bbaa86a68 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -1021,11 +1021,25 @@
# pages. Some guest OS (e.g., Linux TD guest) may require this to
# be set, otherwise they refuse to boot.
#
+# @mrconfigid: ID for non-owner-defined configuration of the guest TD,
+# e.g., run-time or OS configuration (base64 encoded SHA384 digest).
+# Defaults to all zeros.
+#
+# @mrowner: ID for the guest TD’s owner (base64 encoded SHA384 digest).
+# Defaults to all zeros.
+#
+# @mrownerconfig: ID for owner-defined configuration of the guest TD,
+# e.g., specific to the workload rather than the run-time or OS
+# (base64 encoded SHA384 digest). Defaults to all zeros.
+#
# Since: 9.2
##
{ 'struct': 'TdxGuestProperties',
'data': { '*attributes': 'uint64',
- '*sept-ve-disable': 'bool' } }
+ '*sept-ve-disable': 'bool',
+ '*mrconfigid': 'str',
+ '*mrowner': 'str',
+ '*mrownerconfig': 'str' } }

##
# @ThreadContextProperties:
diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c
index 5a9ce2ada89d..887a5324b439 100644
--- a/target/i386/kvm/tdx.c
+++ b/target/i386/kvm/tdx.c
@@ -13,6 +13,7 @@

#include "qemu/osdep.h"
#include "qemu/error-report.h"
+#include "qemu/base64.h"
#include "qapi/error.h"
#include "qom/object_interfaces.h"

@@ -222,6 +223,7 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **errp)
X86CPU *x86cpu = X86_CPU(cpu);
CPUX86State *env = &x86cpu->env;
g_autofree struct kvm_tdx_init_vm *init_vm = NULL;
+ size_t data_len;
int r = 0;

QEMU_LOCK_GUARD(&tdx_guest->lock);
@@ -232,6 +234,37 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **errp)
init_vm = g_malloc0(sizeof(struct kvm_tdx_init_vm) +
sizeof(struct kvm_cpuid_entry2) * KVM_MAX_CPUID_ENTRIES);

+#define SHA384_DIGEST_SIZE 48
+ if (tdx_guest->mrconfigid) {
+ g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrconfigid,
+ strlen(tdx_guest->mrconfigid), &data_len, errp);
+ if (!data || data_len != SHA384_DIGEST_SIZE) {
+ error_setg(errp, "TDX: failed to decode mrconfigid");
+ return -1;
+ }
+ memcpy(init_vm->mrconfigid, data, data_len);
+ }
+
+ if (tdx_guest->mrowner) {
+ g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrowner,
+ strlen(tdx_guest->mrowner), &data_len, errp);
+ if (!data || data_len != SHA384_DIGEST_SIZE) {
+ error_setg(errp, "TDX: failed to decode mrowner");
+ return -1;
+ }
+ memcpy(init_vm->mrowner, data, data_len);
+ }
+
+ if (tdx_guest->mrownerconfig) {
+ g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrownerconfig,
+ strlen(tdx_guest->mrownerconfig), &data_len, errp);
+ if (!data || data_len != SHA384_DIGEST_SIZE) {
+ error_setg(errp, "TDX: failed to decode mrownerconfig");
+ return -1;
+ }
+ memcpy(init_vm->mrownerconfig, data, data_len);
+ }
+
r = setup_td_guest_attributes(x86cpu, errp);
if (r) {
return r;
@@ -279,6 +312,51 @@ static void tdx_guest_set_sept_ve_disable(Object *obj, bool value, Error **errp)
}
}

+static char *tdx_guest_get_mrconfigid(Object *obj, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ return g_strdup(tdx->mrconfigid);
+}
+
+static void tdx_guest_set_mrconfigid(Object *obj, const char *value, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ g_free(tdx->mrconfigid);
+ tdx->mrconfigid = g_strdup(value);
+}
+
+static char *tdx_guest_get_mrowner(Object *obj, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ return g_strdup(tdx->mrowner);
+}
+
+static void tdx_guest_set_mrowner(Object *obj, const char *value, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ g_free(tdx->mrowner);
+ tdx->mrowner = g_strdup(value);
+}
+
+static char *tdx_guest_get_mrownerconfig(Object *obj, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ return g_strdup(tdx->mrownerconfig);
+}
+
+static void tdx_guest_set_mrownerconfig(Object *obj, const char *value, Error **errp)
+{
+ TdxGuest *tdx = TDX_GUEST(obj);
+
+ g_free(tdx->mrownerconfig);
+ tdx->mrownerconfig = g_strdup(value);
+}
+
/* tdx guest */
OBJECT_DEFINE_TYPE_WITH_INTERFACES(TdxGuest,
tdx_guest,
@@ -302,6 +380,14 @@ static void tdx_guest_init(Object *obj)
object_property_add_bool(obj, "sept-ve-disable",
tdx_guest_get_sept_ve_disable,
tdx_guest_set_sept_ve_disable);
+ object_property_add_str(obj, "mrconfigid",
+ tdx_guest_get_mrconfigid,
+ tdx_guest_set_mrconfigid);
+ object_property_add_str(obj, "mrowner",
+ tdx_guest_get_mrowner, tdx_guest_set_mrowner);
+ object_property_add_str(obj, "mrownerconfig",
+ tdx_guest_get_mrownerconfig,
+ tdx_guest_set_mrownerconfig);
}

static void tdx_guest_finalize(Object *obj)
diff --git a/target/i386/kvm/tdx.h b/target/i386/kvm/tdx.h
index e077fd7d1653..bc26e24eb9ac 100644
--- a/target/i386/kvm/tdx.h
+++ b/target/i386/kvm/tdx.h
@@ -22,6 +22,9 @@ typedef struct TdxGuest {
bool initialized;
uint64_t attributes; /* TD attributes */
uint64_t xfam;
+ char *mrconfigid; /* base64 encoded sha348 digest */
+ char *mrowner; /* base64 encoded sha348 digest */
+ char *mrownerconfig; /* base64 encoded sha348 digest */
} TdxGuest;

#ifdef CONFIG_TDX
--
2.34.1