QTEE exposes certain secure services implemented either within the QTEE kernel or via pre-loaded Trusted Applications (TAs). Such always-available services can be readily accessed by TEE client drivers via QTEE's object-IPC protocol if the service is registered as a device on the TEE bus.
One such service is the EFI-variables service, implemented by the uefisecapp TA which enables kernel clients to access EFI variables at runtime.
Maintain a static list of such always-available secure services and add support for the QCOMTEE driver to register these services as devices on the TEE bus during probe.
Signed-off-by: Harshal Dev harshal.dev@oss.qualcomm.com --- drivers/tee/qcomtee/call.c | 160 ++++++++++++++++++++++++++++++++++- drivers/tee/qcomtee/core.c | 9 +- drivers/tee/qcomtee/qcomtee.h | 12 +++ drivers/tee/qcomtee/qcomtee_msg.h | 1 + drivers/tee/qcomtee/qcomtee_object.h | 3 +- 5 files changed, 177 insertions(+), 8 deletions(-)
diff --git a/drivers/tee/qcomtee/call.c b/drivers/tee/qcomtee/call.c index c1bba5fbfa3e..e909955e6b21 100644 --- a/drivers/tee/qcomtee/call.c +++ b/drivers/tee/qcomtee/call.c @@ -662,7 +662,7 @@ static void qcomtee_get_qtee_feature_list(struct tee_context *ctx, u32 id, { struct qcomtee_object *client_env, *service; struct qcomtee_arg u[3] = { 0 }; - int result; + int result, error = 0;
struct qcomtee_object_invoke_ctx *oic __free(kfree) = qcomtee_object_invoke_ctx_alloc(ctx, true); @@ -675,9 +675,13 @@ static void qcomtee_get_qtee_feature_list(struct tee_context *ctx, u32 id,
/* Get ''FeatureVersions Service'' object. */ service = qcomtee_object_get_service(oic, client_env, - QCOMTEE_FEATURE_VER_UID); - if (service == NULL_QCOMTEE_OBJECT) + QCOMTEE_FEATURE_VER_UID, + &error); + if (service == NULL_QCOMTEE_OBJECT) { + if (error) + pr_err("Failed to get service! error: %d\n", error); goto out_failed; + }
/* IB: Feature to query. */ u[0].b.addr = &id; @@ -697,6 +701,153 @@ static void qcomtee_get_qtee_feature_list(struct tee_context *ctx, u32 id, qcomtee_object_put(client_env); }
+/** + * is_qcomtee_service_available() - Check if the QTEE service identified by the UID + * is available + * @ctx: TEE context. + * @uid: 32-bit UID of the service. + * + * Returns true if the service exists and is available. + * Returns false if a service is not exposed by QTEE. + */ +static bool is_qcomtee_service_available(struct tee_context *ctx, u32 uid) +{ + struct qcomtee_object *client_env; + struct qcomtee_object *service; + int error = 0; + bool ret = false; + + struct qcomtee_object_invoke_ctx *oic __free(kfree) = + qcomtee_object_invoke_ctx_alloc(ctx, true); + if (!oic) + return ret; + + client_env = qcomtee_object_get_client_env(oic); + if (client_env == NULL_QCOMTEE_OBJECT) + return ret; + + /* Get service object corresponding to the uid. */ + service = qcomtee_object_get_service(oic, client_env, uid, &error); + if (service != NULL_QCOMTEE_OBJECT) { + qcomtee_object_put(service); + ret = true; + } + + /* When we fail to get the service, QTEE provides the reason. */ + if (error) + pr_err("Failed to get service! error: %d\n", error); + + qcomtee_object_put(client_env); + return ret; +} + +/* + * QTEE Service UUID name space identifier + * + * A random UUID that is allocated as a name space identifier for forming UUID's + * representing secure services exposed by QTEE. + */ +static const uuid_t qtee_service_uuid_ns = UUID_INIT(0xe1b48857, 0x6154, 0x49f9, + 0x93, 0x4e, 0xa2, 0xf2, + 0x0a, 0xba, 0x98, 0x42); + +static const struct qtee_service qtee_services[] = { + { "qcom.tz.uefisecapp", + QCOMTEE_UEFI_SEC_UID } +}; + +static void qtee_release_service(struct device *dev) +{ + struct tee_client_device *qtee_service = to_tee_client_device(dev); + + kfree(qtee_service); +} + +/** + * qtee_enumerate_service() - Enumerate a given QTEE service and register + * it on the TEE bus as a TEE client device + * @ctx: TEE context. + * @service_uuid: UUID of the service to be registered on the TEE bus. + * @uid: 32-bit UID used by QTEE to identify the service. + * + * Returns 0 on success and < 0 on failure. + */ +static int qtee_enumerate_service(struct tee_context *ctx, const char *service_name, + const u32 uid) +{ + struct tee_client_device *qtee_service; + uuid_t service_uuid; + int rc; + + if (!is_qcomtee_service_available(ctx, uid)) + return -ENXIO; + + tee_generate_uuid_v5(&service_uuid, &qtee_service_uuid_ns, service_name, + strlen(service_name)); + + qtee_service = kzalloc_obj(*qtee_service); + if (!qtee_service) + return -ENOMEM; + + qtee_service->dev.bus = &tee_bus_type; + qtee_service->dev.release = qtee_release_service; + if (dev_set_name(&qtee_service->dev, "qtee-svc-%pUb", &service_uuid)) { + kfree(qtee_service); + return -ENOMEM; + } + uuid_copy(&qtee_service->id.uuid, &service_uuid); + + rc = device_register(&qtee_service->dev); + if (rc) { + pr_err("QTEE service registration failed, err: %d\n", rc); + put_device(&qtee_service->dev); + kfree(qtee_service); + return rc; + } + + return 0; +} + +/** + * qtee_enumerate_services() - Enumerate all the secure services exposed by QTEE + * from the static 'qtee_services' list and register them on the TEE bus as + * TEE client devices. + * + * Not all versions of QTEE support a given service. Hence, we try to + * enumerate as many services from the 'qtee_services' list as possible. + * Not being able to enumerate a service shouldn't cause the driver probe + * to fail since none of the services in the list are mandatory for + * establishing communication with QTEE. + * @ctx: TEE context. + */ +static void qtee_enumerate_services(struct tee_context *ctx) +{ + int rc; + u32 idx; + + for (idx = 0; idx < ARRAY_SIZE(qtee_services); idx++) { + rc = qtee_enumerate_service(ctx, qtee_services[idx].name, + qtee_services[idx].uid); + if (rc == -ENXIO) + pr_err("QTEE does not implement service %d.\n", + qtee_services[idx].uid); + } +} + +static int qtee_unregister_service(struct device *dev, void *data) +{ + if (!strncmp(dev_name(dev), "qtee-svc", strlen("qtee-svc"))) + device_unregister(dev); + + return 0; +} + +static void qtee_unregister_services(void) +{ + bus_for_each_dev(&tee_bus_type, NULL, NULL, + qtee_unregister_service); +} + static const struct tee_driver_ops qcomtee_ops = { .get_version = qcomtee_get_version, .open = qcomtee_open, @@ -778,6 +929,8 @@ static int qcomtee_probe(struct platform_device *pdev) QTEE_VERSION_GET_MINOR(qcomtee->qtee_version), QTEE_VERSION_GET_PATCH(qcomtee->qtee_version));
+ qtee_enumerate_services(qcomtee->ctx); + return 0;
err_dest_wq: @@ -807,6 +960,7 @@ static void qcomtee_remove(struct platform_device *pdev) { struct qcomtee *qcomtee = platform_get_drvdata(pdev);
+ qtee_unregister_services(); teedev_close_context(qcomtee->ctx); /* Wait for RELEASE operations to be processed for QTEE objects. */ tee_device_unregister(qcomtee->teedev); diff --git a/drivers/tee/qcomtee/core.c b/drivers/tee/qcomtee/core.c index b1cb50e434f0..4e39e867c3e9 100644 --- a/drivers/tee/qcomtee/core.c +++ b/drivers/tee/qcomtee/core.c @@ -896,19 +896,20 @@ qcomtee_object_get_client_env(struct qcomtee_object_invoke_ctx *oic)
struct qcomtee_object * qcomtee_object_get_service(struct qcomtee_object_invoke_ctx *oic, - struct qcomtee_object *client_env, u32 uid) + struct qcomtee_object *client_env, u32 uid, + int *result) { struct qcomtee_arg u[3] = { 0 }; - int ret, result; + int ret;
u[0].b.addr = &uid; u[0].b.size = sizeof(uid); u[0].type = QCOMTEE_ARG_TYPE_IB; u[1].type = QCOMTEE_ARG_TYPE_OO; ret = qcomtee_object_do_invoke(oic, client_env, QCOMTEE_CLIENT_ENV_OPEN, - u, &result); + u, result);
- if (ret || result) + if (ret || *result) return NULL_QCOMTEE_OBJECT;
return u[1].o; diff --git a/drivers/tee/qcomtee/qcomtee.h b/drivers/tee/qcomtee/qcomtee.h index f39bf63fd1c2..66d305a46c0a 100644 --- a/drivers/tee/qcomtee/qcomtee.h +++ b/drivers/tee/qcomtee/qcomtee.h @@ -17,6 +17,8 @@ #define QCOMTEE_OBJREF_FLAG_USER BIT(1) #define QCOMTEE_OBJREF_FLAG_MEM BIT(2)
+#define QTEE_UUID_NS_NAME_SIZE 128 + /** * struct qcomtee - Main service struct. * @teedev: client device. @@ -39,6 +41,16 @@ struct qcomtee { u32 qtee_version; };
+/** + * struct qtee_service - A secure service exposed by QTEE identified by a 32-bit UID. + * @name: Name of the QTEE service. + * @uid: 32-bit UID used by QTEE to identify the service. + */ +struct qtee_service { + const char *name; + const u32 uid; +}; + void qcomtee_fetch_async_reqs(struct qcomtee_object_invoke_ctx *oic); struct qcomtee_object *qcomtee_idx_erase(struct qcomtee_object_invoke_ctx *oic, u32 idx); diff --git a/drivers/tee/qcomtee/qcomtee_msg.h b/drivers/tee/qcomtee/qcomtee_msg.h index 878f70178a5b..ecaf8db67d45 100644 --- a/drivers/tee/qcomtee/qcomtee_msg.h +++ b/drivers/tee/qcomtee/qcomtee_msg.h @@ -105,6 +105,7 @@ union qcomtee_msg_arg { #define QTEE_VERSION_GET_MINOR(x) (((x) >> 12) & 0xffU) #define QTEE_VERSION_GET_PATCH(x) ((x) >> 0 & 0xfffU)
+#define QCOMTEE_UEFI_SEC_UID 413 /* Response types as returned from qcomtee_object_invoke_ctx_invoke(). */
/* The message contains a callback request. */ diff --git a/drivers/tee/qcomtee/qcomtee_object.h b/drivers/tee/qcomtee/qcomtee_object.h index 7bd6e23b038c..f4cb9b8fcbd4 100644 --- a/drivers/tee/qcomtee/qcomtee_object.h +++ b/drivers/tee/qcomtee/qcomtee_object.h @@ -316,6 +316,7 @@ qcomtee_object_get_client_env(struct qcomtee_object_invoke_ctx *oic);
struct qcomtee_object * qcomtee_object_get_service(struct qcomtee_object_invoke_ctx *oic, - struct qcomtee_object *client_env, u32 uid); + struct qcomtee_object *client_env, u32 uid, + int *result);
#endif /* QCOMTEE_OBJECT_H */