From 2c8e4906101c4f3069101e133e7177b02bf557ac Mon Sep 17 00:00:00 2001
From: Jean-Philippe Brucker <jean-philippe@linaro.org>
Date: 2022年10月27日 19:22:48 +0100
Subject: [PATCH 14/29] target/arm/kvm-rme: Add measurement algorithm property
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Reference:https://git.codelinaro.org/linaro/dcap/qemu/-/commit/26ed0bafc44a8d4d8fcc46a1ee7a2b8aa35b1c33

This option selects which measurement algorithm to use for attestation.
Supported values are SHA256 and SHA512. Default to SHA512 arbitrarily.

SHA512 is generally faster on 64-bit architectures. On a few arm64 CPUs
I tested SHA256 is much faster, but that's most likely because they only
support acceleration via FEAT_SHA256 (Armv8.0) and not FEAT_SHA512
(Armv8.2). Future CPUs supporting RME are likely to also support
FEAT_SHA512.

Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Eduardo Habkost <eduardo@habkost.net>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: houmingyong <houmingyong@huawei.com>
---
 qapi/qom.json | 20 +++++++++++++++++++-
 target/arm/kvm-rme.c | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/qapi/qom.json b/qapi/qom.json
index b85bb4673..a980568be 100644
--- a/qapi/qom.json
+++ b/qapi/qom.json
@@ -909,6 +909,20 @@
 'data': { '*cpu-affinity': ['uint16'],
 '*node-affinity': ['uint16'] } }
 
+##
+# @RmeGuestMeasurementAlgorithm:
+#
+# @sha256: Use the SHA256 algorithm
+#
+# @sha512: Use the SHA512 algorithm
+#
+# Algorithm to use for realm measurements
+#
+# Since: 10.0
+##
+{ 'enum': 'RmeGuestMeasurementAlgorithm',
+ 'data': ['sha256', 'sha512'] }
+
 ##
 # @RmeGuestProperties:
 #
@@ -918,10 +932,14 @@
 # This optional parameter allows to uniquely identify the VM instance
 # during attestation. (default: all-zero)
 #
+# @measurement-algorithm: Realm measurement algorithm
+# (default: sha512)
+#
 # Since: 10.0
 ##
 { 'struct': 'RmeGuestProperties',
- 'data': { '*personalization-value': 'str' } }
+ 'data': { '*personalization-value': 'str',
+ '*measurement-algorithm': 'RmeGuestMeasurementAlgorithm' } }
 
 ##
 # @ObjectType:
diff --git a/target/arm/kvm-rme.c b/target/arm/kvm-rme.c
index e8976e474..5e785fa3b 100644
--- a/target/arm/kvm-rme.c
+++ b/target/arm/kvm-rme.c
@@ -36,6 +36,7 @@ struct RmeGuest {
 
 char *personalization_value_str;
 uint8_t personalization_value[ARM_RME_CONFIG_RPV_SIZE];
+ RmeGuestMeasurementAlgorithm measurement_algo;
 
 RmeRamRegion init_ram;
 };
@@ -59,6 +60,19 @@ static int rme_configure_one(RmeGuest *guest, uint32_t cfg, Error **errp)
 memcpy(args.rpv, guest->personalization_value, ARM_RME_CONFIG_RPV_SIZE);
 cfg_str = "personalization value";
 break;
+ case ARM_RME_CONFIG_HASH_ALGO:
+ switch (guest->measurement_algo) {
+ case RME_GUEST_MEASUREMENT_ALGORITHM_SHA256:
+ args.hash_algo = ARM_RME_CONFIG_MEASUREMENT_ALGO_SHA256;
+ break;
+ case RME_GUEST_MEASUREMENT_ALGORITHM_SHA512:
+ args.hash_algo = ARM_RME_CONFIG_MEASUREMENT_ALGO_SHA512;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+ cfg_str = "hash algorithm";
+ break;
 default:
 g_assert_not_reached();
 }
@@ -77,6 +91,7 @@ static int rme_configure(Error **errp)
 size_t option;
 const uint32_t config_options[] = {
 ARM_RME_CONFIG_RPV,
+ ARM_RME_CONFIG_HASH_ALGO,
 };
 
 for (option = 0; option < ARRAY_SIZE(config_options); option++) {
@@ -248,12 +263,34 @@ static void rme_set_rpv(Object *obj, const char *value, Error **errp)
 guest->personalization_value_str = g_strdup(value);
 }
 
+static int rme_get_measurement_algo(Object *obj, Error **errp)
+{
+ RmeGuest *guest = RME_GUEST(obj);
+
+ return guest->measurement_algo;
+}
+
+static void rme_set_measurement_algo(Object *obj, int algo, Error **errp)
+{
+ RmeGuest *guest = RME_GUEST(obj);
+
+ guest->measurement_algo = algo;
+}
+
 static void rme_guest_class_init(ObjectClass *oc, void *data)
 {
 object_class_property_add_str(oc, "personalization-value", rme_get_rpv,
 rme_set_rpv);
 object_class_property_set_description(oc, "personalization-value",
 "Realm personalization value (64 bytes encodede in base64)");
+
+ object_class_property_add_enum(oc, "measurement-algorithm",
+ "RmeGuestMeasurementAlgorithm",
+ &RmeGuestMeasurementAlgorithm_lookup,
+ rme_get_measurement_algo,
+ rme_set_measurement_algo);
+ object_class_property_set_description(oc, "measurement-algorithm",
+ "Realm measurement algorithm ('sha256', 'sha512')");
 }
 
 static void rme_guest_init(Object *obj)
@@ -263,6 +300,7 @@ static void rme_guest_init(Object *obj)
 exit(1);
 }
 rme_guest = RME_GUEST(obj);
+ rme_guest->measurement_algo = RME_GUEST_MEASUREMENT_ALGORITHM_SHA512;
 }
 
 static void rme_guest_finalize(Object *obj)
-- 
2.43.0