Merge pull request xapi-project#34 from koushikcgit/CA-141366

[HFX-1302] CA 141366: Xenopsd tries to build domain when it already knows it will fail (not enough memory)

Author: simonjbeaumont

ocaml/xenops/domain.ml

@@ -69,6 +69,7 @@ let filtered_xsdata =
 	List.filter allowed
 
 exception Restore_signature_mismatch
+exception Not_enough_memory of int64
 exception Domain_build_failed
 exception Domain_restore_failed
 exception Domain_restore_truncated_hvmstate
@@ -465,7 +466,11 @@ let build_pre ~xc ~xs ~vcpus ~xen_max_mib ~shadow_mib ~required_host_free_mib do
 	let uuid = get_uuid ~xc domid in
 	debug "VM = %s; domid = %d; waiting for %Ld MiB of free host memory" (Uuid.to_string uuid) domid required_host_free_mib;
 	(* CA-39743: Wait, if necessary, for the Xen scrubber to catch up. *)
-	let (_: bool) = wait_xen_free_mem ~xc (Memory.kib_of_mib required_host_free_mib) in
+	if not(wait_xen_free_mem ~xc (Memory.kib_of_mib required_host_free_mib)) then begin
+		error "VM = %s; domid = %d; Failed waiting for Xen to free %Ld MiB"
+			(Uuid.to_string uuid) domid required_host_free_mib;
+		raise (Not_enough_memory (Memory.bytes_of_mib required_host_free_mib))
+	end;
 
 	let shadow_mib = Int64.to_int shadow_mib in
 

ocaml/xenops/domain.mli

@@ -18,6 +18,7 @@ open Device_common
 type domid = Xenctrl.domid
 
 exception Restore_signature_mismatch
+exception Not_enough_memory of int64
 exception Domain_build_failed
 exception Domain_restore_failed
 exception Xenguest_protocol_failure of string (* internal protocol failure *)

ocaml/xenops/xenops_server_xen.ml

@@ -1079,8 +1079,11 @@ module VM = struct
 				let m = Printf.sprintf "VM = %s; domid = %d; Bootloader.Error_from_bootloader %s" vm.Vm.id domid x in
 				debug "%s" m;
 				raise (Bootloader_error (vm.Vm.id, x))
+			| Domain.Not_enough_memory m ->
+				debug "VM = %s; domid = %d; Domain.Not_enough_memory. Needed: %Ld bytes" vm.Vm.id domid m;
+				raise (Not_enough_memory m)
 			| e ->
-				let m = Printf.sprintf "VM = %s; domid = %d; Bootloader error: %s" vm.Vm.id domid (Printexc.to_string e) in
+				let m = Printf.sprintf "VM = %s; domid = %d; Error: %s" vm.Vm.id domid (Printexc.to_string e) in
 				debug "%s" m;
 				raise e