CA-273649: add xapi restriction when attach several host's usbs

This change is to add restriction when attaching usb to vm that
the host of the usb is not in possible_hosts that vm can boot on.

Signed-off-by: Taoyong Ding <taoyong.ding@citrix.com>

Author: taoyongd

ocaml/idl/datamodel.ml

@@ -1515,7 +1515,9 @@ let _ =
   error Api_errors.pusb_vdi_conflict [ "PUSB"; "VDI" ]
     ~doc:"The VDI corresponding to this PUSB has existing VBDs." ();
   error Api_errors.vm_has_vusbs ["VM"]
-    ~doc:"The operation is not allowed when the VM has VUSBs." ()
+    ~doc:"The operation is not allowed when the VM has VUSBs." ();
+  error Api_errors.pusb_not_in_possible_hosts [ "pusb"; "possible_hosts" ]
+    ~doc:"The VM can't boot on the host that belongs to the pusb; it can boot only on the following hosts." ()
 
 let _ =
   message (fst Api_messages.ha_pool_overcommitted) ~doc:"Pool has become overcommitted: it can no longer guarantee to restart protected VMs if the configured number of hosts fail." ();

ocaml/xapi-consts/api_errors.ml

@@ -580,3 +580,4 @@ let too_many_vusbs = "TOO_MANY_VUSBS"
 let passthrough_not_enabled = "PASSTHROUGH_NOT_ENABLED"
 let pusb_vdi_conflict = "PUSB_VDI_CONFLICT"
 let vm_has_vusbs = "VM_HAS_VUSBS"
+let pusb_not_in_possible_hosts = "PUSB_NOT_IN_POSSIBLE_HOSTS"

ocaml/xapi/xapi_vusb.ml

@@ -34,6 +34,14 @@ let create ~__context ~vM ~uSB_group ~other_config =
         another vusb can not create with the same USB_group. *)
     if vusbs <> [] then
       raise (Api_errors.Server_error(Api_errors.usb_group_conflict, [Ref.string_of uSB_group]));
+
+    (* All USBs that will be attached to the VM must be on the same host, as USB from host A can
+      not attach to the vm resident on host B. *)
+    let possible_hosts = Xapi_vm.get_possible_hosts ~__context ~vm:vM in
+    let pusb = Helpers.get_first_pusb ~__context uSB_group in
+    let host = Db.PUSB.get_host ~__context ~self:pusb in
+    if not (List.mem host possible_hosts) then
+      raise (Api_errors.Server_error (Api_errors.pusb_not_in_possible_hosts, [Ref.string_of pusb; String.concat ";" (List.map Ref.string_of possible_hosts)]));
     (* We won't attach VUSB when VM ha_restart_priority is set to 'restart'  *)
     let ha_restart_priority = Db.VM.get_ha_restart_priority ~__context ~self:vM in
     match ha_restart_priority with