Add secureboot-enforce setting in xapi.conf

This setting will be used by varstored to know
wheter to allow the start of a VM that has no certificates
when secureboot is enabled by writing in the xenstore in
`/local/domain/<domid>/platform/secureboot-enforce`.

Default: false to keep the previous behavior.

See: xapi-project/varstored#19

Signed-off-by: BenjiReis <[email protected]>

Author: benjamreis

ocaml/xapi/xapi_globs.ml

@@ -998,6 +998,8 @@ let prefer_nbd_attach = ref false
 (** 1 MiB *)
 let max_observer_file_size = ref (1 lsl 20)
 
+let secureboot_enforce = ref false
+
 let xapi_globs_spec =
   [
     ( "master_connection_reset_timeout"
@@ -1470,6 +1472,11 @@ let other_options =
     , (fun () -> string_of_int !max_observer_file_size)
     , "The maximum size of log files for saving spans"
     )
+  ; ( "secureboot-enforce"
+    , Arg.Set secureboot_enforce
+    , (fun () -> string_of_bool !secureboot_enforce)
+    , "Do not start a VM with no SB certificates if secureboot is set to on"
+    )
   ]
 
 (* The options can be set with the variable xapiflags in /etc/sysconfig/xapi.

ocaml/xapi/xapi_vm.ml

@@ -605,6 +605,10 @@ let create ~__context ~name_label ~name_description ~power_state ~user_version
     else
       other_config
   in
+  let _platform = if !Xapi_globs.secureboot_enforce
+    then ("secureboot-enforce", "true") :: platform
+    else platform
+  in
   (* NB apart from the above, parameter validation is delayed until VM.start *)
   let uuid = Uuidx.make () in
   let vm_ref = Ref.make () in
@@ -664,7 +668,7 @@ let create ~__context ~name_label ~name_description ~power_state ~user_version
     ~memory_static_min ~vCPUs_params ~vCPUs_at_startup ~vCPUs_max
     ~actions_after_softreboot ~actions_after_shutdown ~actions_after_reboot
     ~actions_after_crash ~hVM_boot_policy ~hVM_boot_params
-    ~hVM_shadow_multiplier ~suspend_VDI:_suspend_VDI ~platform ~nVRAM ~pV_kernel
+    ~hVM_shadow_multiplier ~suspend_VDI:_suspend_VDI ~platform:_platform ~nVRAM ~pV_kernel
     ~pV_ramdisk ~pV_args ~pV_bootloader ~pV_bootloader_args ~pV_legacy_args
     ~pCI_bus ~other_config ~domid:(-1L) ~domarch:""
     ~last_boot_CPU_flags:_last_boot_CPU_flags ~is_control_domain:false ~metrics