1/******************************************************************************
2 * kexec.h - Public portion
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to
6 * deal in the Software without restriction, including without limitation the
7 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
8 * sell copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
19 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
20 * DEALINGS IN THE SOFTWARE.
21 *
22 * Xen port written by:
23 * - Simon 'Horms' Horman <horms@verge.net.au>
24 * - Magnus Damm <magnus@valinux.co.jp>
25 */
26
27#ifndef _XEN_PUBLIC_KEXEC_H
28#define _XEN_PUBLIC_KEXEC_H
29
30
31/* This file describes the Kexec / Kdump hypercall interface for Xen.
32 *
33 * Kexec under vanilla Linux allows a user to reboot the physical machine
34 * into a new user-specified kernel. The Xen port extends this idea
35 * to allow rebooting of the machine from dom0. When kexec for dom0
36 * is used to reboot,  both the hypervisor and the domains get replaced
37 * with some other kernel. It is possible to kexec between vanilla
38 * Linux and Xen and back again. Xen to Xen works well too.
39 *
40 * The hypercall interface for kexec can be divided into three main
41 * types of hypercall operations:
42 *
43 * 1) Range information:
44 *    This is used by the dom0 kernel to ask the hypervisor about various
45 *    address information. This information is needed to allow kexec-tools
46 *    to fill in the ELF headers for /proc/vmcore properly.
47 *
48 * 2) Load and unload of images:
49 *    There are no big surprises here, the kexec binary from kexec-tools
50 *    runs in userspace in dom0. The tool loads/unloads data into the
51 *    dom0 kernel such as new kernel, initramfs and hypervisor. When
52 *    loaded the dom0 kernel performs a load hypercall operation, and
53 *    before releasing all page references the dom0 kernel calls unload.
54 *
55 * 3) Kexec operation:
56 *    This is used to start a previously loaded kernel.
57 */
58
59#include "xen.h"
60
61#if defined(__i386__) || defined(__x86_64__)
62#define KEXEC_XEN_NO_PAGES 17
63#endif
64
65/*
66 * Prototype for this hypercall is:
67 *  int kexec_op(int cmd, void *args)
68 * @cmd  == KEXEC_CMD_...
69 *          KEXEC operation to perform
70 * @args == Operation-specific extra arguments (NULL if none).
71 */
72
73/*
74 * Kexec supports two types of operation:
75 * - kexec into a regular kernel, very similar to a standard reboot
76 *   - KEXEC_TYPE_DEFAULT is used to specify this type
77 * - kexec into a special "crash kernel", aka kexec-on-panic
78 *   - KEXEC_TYPE_CRASH is used to specify this type
79 *   - parts of our system may be broken at kexec-on-panic time
80 *     - the code should be kept as simple and self-contained as possible
81 */
82
83#define KEXEC_TYPE_DEFAULT 0
84#define KEXEC_TYPE_CRASH   1
85
86
87/* The kexec implementation for Xen allows the user to load two
88 * types of kernels, KEXEC_TYPE_DEFAULT and KEXEC_TYPE_CRASH.
89 * All data needed for a kexec reboot is kept in one xen_kexec_image_t
90 * per "instance". The data mainly consists of machine address lists to pages
91 * together with destination addresses. The data in xen_kexec_image_t
92 * is passed to the "code page" which is one page of code that performs
93 * the final relocations before jumping to the new kernel.
94 */
95
96typedef struct xen_kexec_image {
97#if defined(__i386__) || defined(__x86_64__)
98    unsigned long page_list[KEXEC_XEN_NO_PAGES];
99#endif
100#if defined(__ia64__)
101    unsigned long reboot_code_buffer;
102#endif
103    unsigned long indirection_page;
104    unsigned long start_address;
105} xen_kexec_image_t;
106
107/*
108 * Perform kexec having previously loaded a kexec or kdump kernel
109 * as appropriate.
110 * type == KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH [in]
111 */
112#define KEXEC_CMD_kexec                 0
113typedef struct xen_kexec_exec {
114    int type;
115} xen_kexec_exec_t;
116
117/*
118 * Load/Unload kernel image for kexec or kdump.
119 * type  == KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH [in]
120 * image == relocation information for kexec (ignored for unload) [in]
121 */
122#define KEXEC_CMD_kexec_load            1
123#define KEXEC_CMD_kexec_unload          2
124typedef struct xen_kexec_load {
125    int type;
126    xen_kexec_image_t image;
127} xen_kexec_load_t;
128
129#define KEXEC_RANGE_MA_CRASH      0 /* machine address and size of crash area */
130#define KEXEC_RANGE_MA_XEN        1 /* machine address and size of Xen itself */
131#define KEXEC_RANGE_MA_CPU        2 /* machine address and size of a CPU note */
132#define KEXEC_RANGE_MA_XENHEAP    3 /* machine address and size of xenheap
133                                     * Note that although this is adjacent
134                                     * to Xen it exists in a separate EFI
135                                     * region on ia64, and thus needs to be
136                                     * inserted into iomem_machine separately */
137#define KEXEC_RANGE_MA_BOOT_PARAM 4 /* machine address and size of
138                                     * the ia64_boot_param */
139#define KEXEC_RANGE_MA_EFI_MEMMAP 5 /* machine address and size of
140                                     * of the EFI Memory Map */
141#define KEXEC_RANGE_MA_VMCOREINFO 6 /* machine address and size of vmcoreinfo */
142
143/*
144 * Find the address and size of certain memory areas
145 * range == KEXEC_RANGE_... [in]
146 * nr    == physical CPU number (starting from 0) if KEXEC_RANGE_MA_CPU [in]
147 * size  == number of bytes reserved in window [out]
148 * start == address of the first byte in the window [out]
149 */
150#define KEXEC_CMD_kexec_get_range       3
151typedef struct xen_kexec_range {
152    int range;
153    int nr;
154    unsigned long size;
155    unsigned long start;
156} xen_kexec_range_t;
157
158#endif /* _XEN_PUBLIC_KEXEC_H */
159
160/*
161 * Local variables:
162 * mode: C
163 * c-set-style: "BSD"
164 * c-basic-offset: 4
165 * tab-width: 4
166 * indent-tabs-mode: nil
167 * End:
168 */
169