vmm: Add option for enabling SGX EPC regions

Introducing the new CLI option --sgx-epc along with the OpenAPI
structure SgxEpcConfig, so that a user can now enable one or multiple
SGX Enclave Page Cache sections within a contiguous region from the
guest address space.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

vmm/src/api/openapi/cloud-hypervisor.yaml

@@ -410,6 +410,10 @@ components:
             $ref: '#/components/schemas/DeviceConfig'
         vsock:
             $ref: '#/components/schemas/VsockConfig'
+        sgx_epc:
+          type: array
+          items:
+            $ref: '#/components/schemas/SgxEpcConfig'
         iommu:
           type: boolean
           default: false
@@ -670,6 +674,18 @@ components:
         id:
           type: string
 
+    SgxEpcConfig:
+      required:
+      - size
+      type: object
+      properties:
+        size:
+          type: integer
+          format: uint64
+        prefault:
+          type: boolean
+          default: false
+
     VmResize:
       type: object
       properties: