(* Memory info command for virtual domains.
   (C) Copyright 2008 Richard W.M. Jones, Red Hat Inc.
   http://libvirt.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *)

open Printf

open Virt_mem_gettext.Gettext
open Virt_mem_utils
open Virt_mem_types

open Kernel_task_struct

let max_tasks = 10000

let find_tasks debug image ksymmap kernel_version =
  if not (task_struct_known kernel_version) then (
    eprintf (f_"%s: %s: unknown kernel version
Try a newer version of virt-mem, or if the guest is not from a
supported Linux distribution, see this page about adding support:
  http://et.redhat.com/~rjones/virt-mem/faq.html\n")
      image.domname kernel_version;
    image, None
  ) else (
    let size = task_struct_size kernel_version in

    let init_task_addr =
      try Some (Ksymmap.find "init_task" ksymmap)
      with Not_found ->
	eprintf (f_"%s: could not find init_task in kernel image\n")
	  image.domname;
	None in
    match init_task_addr with
    | None -> image, None
    | Some init_task_addr ->
	let { field_offset = offset } =
	  field_signature_of_task_struct_tasks'next kernel_version in

	let lh = Virt_mem_list_head.create_base image init_task_addr offset in
	let image, lh = Virt_mem_list_head.load_all lh size in

	let tasks, _ =
	  Virt_mem_list_head.fold lh ([], 0) (
	    fun (tasks, i) addr ->
	      if i > max_tasks then
		failwith (sprintf (f_"%s: too many tasks") image.domname);

	      let task = get_task_struct kernel_version image.mem addr in
	      let tasks = task :: tasks in
	      (tasks, i+1)
	  ) in

	(* Convert to the internal format. *)
	let tasks = List.rev_map (
	  fun task ->
	    { task_state = task.task_struct_state;
	      task_prio = task.task_struct_prio;
	      task_normal_prio = task.task_struct_normal_prio;
	      task_static_prio = task.task_struct_static_prio;
	      task_comm = truncate_c_string task.task_struct_comm;
	      task_pid = task.task_struct_pid }
	) tasks in

	image, Some tasks
  )