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 } =
29 (* I don't know why but this symbol doesn't exist in 2.6.9
30 * even in kallsyms. Hence this won't work with that kernel.
31 * It's possible we can fall back to memory scanning. XXX
33 let log_buf = Ksymmap.find "log_buf" ksyms in
34 let log_buf = follow_pointer mem log_buf in
35 let log_buf_len = Ksymmap.find "log_buf_len" ksyms in
36 let log_buf_len = Int64.of_int32 (get_C_int mem log_buf_len) in
37 (* let log_start = Ksymmap.find "log_start" ksyms in
38 let log_start = get_C_long mem log_start in *)
39 let log_end = Ksymmap.find "log_end" ksyms in
40 let log_end = get_C_long mem log_end in
41 (* let con_start = Ksymmap.find "con_start" ksyms in
42 let con_start = get_C_long mem con_start in *)
43 let logged_chars = Ksymmap.find "logged_chars" ksyms in
44 let logged_chars = get_C_long mem logged_chars in
46 (* This is basically the same algorithm from printk.c:do_syslog
47 * type=3, translated into OCaml. Unlike the kernel version
48 * however we don't copy the buffer backwards.
51 let addr = log_buf +^ (idx &^ (log_buf_len -^ 1L)) in
52 Char.chr (get_byte mem addr)
55 let count = log_buf_len in
56 let count = if count > logged_chars then logged_chars else count in
57 let limit = log_end in
61 let j = limit-^1L-^i in
62 if j +^ log_buf_len >= log_end then (
63 let c = get_log_buf j in
72 eprintf (f_"%s: could not find kernel log buffer in kernel image\n")
75 let summary = s_"display kernel messages"
76 let description = s_"\
77 virt-dmesg prints the kernel messages for virtual machines running
78 under libvirt. The output is similar to the ordinary dmesg command
79 run inside the virtual machine."
81 let () = Virt_mem.register "dmesg" summary description ~needs_ksyms:true ~run