tools/arm: tee: add "tee" option for xl.cfg

This enumeration controls TEE type for a domain. Currently there is
two possible options: either 'none' or 'optee'.

'none' is the default value and it basically disables TEE support at
all.

'optee' enables access to the OP-TEE running on a host machine. This
requires special OP-TEE build with virtualization support enabled.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

docs/man/xl.cfg.5.pod.in

@@ -1544,6 +1544,35 @@ Set maximum height for pointer device.
 
 =back
 
+=item B<tee="STRING">
+
+B<Arm only.> Set TEE type for the guest. TEE is a Trusted Execution
+Environment -- separate secure OS found on some platforms. B<STRING> can be one of the:
+
+=over 4
+
+=item B<none>
+
+"Don't allow the guest to use TEE if present on the platform. This is
+the default value.
+
+=item B<optee>
+
+Allow a guest to access the host OP-TEE OS. Xen will mediate the
+access to OP-TEE and the resource isolation will be provided directly
+by OP-TEE. OP-TEE itself may limit the number of guests that can
+concurrently use it. This requires a virtualization-aware OP-TEE for
+this to work.
+
+You can refer to
+L<OP-TEE documentation|https://optee.readthedocs.io/architecture/virtualization.html>
+for more information about how to enable and configure virtualization support
+in OP-TEE.
+
+This feature is a B<technology preview>.
+
+=back
+
 =back
 
 =head2 Paravirtualised (PV) Guest Specific Options

tools/libxl/libxl.h

@@ -273,6 +273,11 @@
  */
 #define LIBXL_HAVE_BUILDINFO_ARM_GIC_VERSION 1
 
+/*
+ * libxl_domain_build_info has the arch_arm.tee field.
+ */
+#define LIBXL_HAVE_BUILDINFO_ARCH_ARM_TEE 1
+
 /*
  * LIBXL_HAVE_SOFT_RESET indicates that libxl supports performing
  * 'soft reset' for domains and there is 'soft_reset' shutdown reason

tools/libxl/libxl_arm.c

@@ -89,6 +89,19 @@ int libxl__arch_domain_prepare_config(libxl__gc *gc,
         return ERROR_FAIL;
     }
 
+    switch (d_config->b_info.tee) {
+    case LIBXL_TEE_TYPE_NONE:
+        config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_NONE;
+        break;
+    case LIBXL_TEE_TYPE_OPTEE:
+        config->arch.tee_type = XEN_DOMCTL_CONFIG_TEE_OPTEE;
+        break;
+    default:
+        LOG(ERROR, "Unknown TEE type %d",
+            d_config->b_info.tee);
+        return ERROR_FAIL;
+    }
+
     return 0;
 }
 

tools/libxl/libxl_types.idl

@@ -460,6 +460,11 @@ libxl_gic_version = Enumeration("gic_version", [
     (0x30, "v3")
     ], init_val = "LIBXL_GIC_VERSION_DEFAULT")
 
+libxl_tee_type = Enumeration("tee_type", [
+    (0, "none"),
+    (1, "optee")
+    ], init_val = "LIBXL_TEE_TYPE_NONE")
+
 libxl_rdm_reserve = Struct("rdm_reserve", [
     ("strategy",    libxl_rdm_reserve_strategy),
     ("policy",      libxl_rdm_reserve_policy),
@@ -537,6 +542,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
     ("nested_hvm",       libxl_defbool),
     ("apic",             libxl_defbool),
     ("dm_restrict",      libxl_defbool),
+    ("tee",              libxl_tee_type),
     ("u", KeyedUnion(None, libxl_domain_type, "type",
                 [("hvm", Struct(None, [("firmware",         string),
                                        ("bios",             libxl_bios_type),

tools/xl/xl_parse.c

@@ -2691,6 +2691,15 @@ skip_usbdev:
         }
     }
 
+    if (!xlu_cfg_get_string (config, "tee", &buf, 1)) {
+        e = libxl_tee_type_from_string(buf, &b_info->tee);
+        if (e) {
+            fprintf(stderr,
+                    "Unknown tee \"%s\" specified\n", buf);
+            exit(-ERROR_FAIL);
+        }
+    }
+
     parse_vkb_list(config, d_config);
 
     xlu_cfg_destroy(config);