1 (* Memory info for virtual domains.
2 (C) Copyright 2008 Richard W.M. Jones, Red Hat Inc.
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 open Virt_mem_gettext.Gettext
27 let run debug { domname = domname; mem = mem } { ksyms = ksyms } =
28 let ksyms = Option.get ksyms in
30 (* I don't know why but this symbol doesn't exist in 2.6.9
31 * even in kallsyms. Hence this won't work with that kernel.
32 * It's possible we can fall back to memory scanning. XXX
34 let log_buf = Ksymmap.find "log_buf" ksyms in
35 let log_buf = follow_pointer mem log_buf in
36 let log_buf_len = Ksymmap.find "log_buf_len" ksyms in
37 let log_buf_len = Int64.of_int32 (get_C_int mem log_buf_len) in
38 (* let log_start = Ksymmap.find "log_start" ksyms in
39 let log_start = get_C_long mem log_start in *)
40 let log_end = Ksymmap.find "log_end" ksyms in
41 let log_end = get_C_long mem log_end in
42 (* let con_start = Ksymmap.find "con_start" ksyms in
43 let con_start = get_C_long mem con_start in *)
44 let logged_chars = Ksymmap.find "logged_chars" ksyms in
45 let logged_chars = get_C_long mem logged_chars in
47 (* This is basically the same algorithm from printk.c:do_syslog
48 * type=3, translated into OCaml. Unlike the kernel version
49 * however we don't copy the buffer backwards.
52 let addr = log_buf +^ (idx &^ (log_buf_len -^ 1L)) in
53 Char.chr (get_byte mem addr)
56 let count = log_buf_len in
57 let count = if count > logged_chars then logged_chars else count in
58 let limit = log_end in
62 let j = limit-^1L-^i in
63 if j +^ log_buf_len >= log_end then (
64 let c = get_log_buf j in
73 eprintf (f_"%s: could not find kernel log buffer in kernel image\n")
76 let summary = s_"display kernel messages"
77 let description = s_"\
78 virt-dmesg prints the kernel messages for virtual machines running
79 under libvirt. The output is similar to the ordinary dmesg command
80 run inside the virtual machine."
82 let () = Virt_mem.register "dmesg" summary description ~needs_ksyms:true ~run