xref: /openbmc/linux/include/xen/interface/elfnote.h (revision 9e2b3e83)
1 /* SPDX-License-Identifier: MIT */
2 /******************************************************************************
3  * elfnote.h
4  *
5  * Definitions used for the Xen ELF notes.
6  *
7  * Copyright (c) 2006, Ian Campbell, XenSource Ltd.
8  */
9 
10 #ifndef __XEN_PUBLIC_ELFNOTE_H__
11 #define __XEN_PUBLIC_ELFNOTE_H__
12 
13 /*
14  * The notes should live in a SHT_NOTE segment and have "Xen" in the
15  * name field.
16  *
17  * Numeric types are either 4 or 8 bytes depending on the content of
18  * the desc field.
19  *
20  * LEGACY indicated the fields in the legacy __xen_guest string which
21  * this a note type replaces.
22  *
23  * String values (for non-legacy) are NULL terminated ASCII, also known
24  * as ASCIZ type.
25  */
26 
27 /*
28  * NAME=VALUE pair (string).
29  */
30 #define XEN_ELFNOTE_INFO           0
31 
32 /*
33  * The virtual address of the entry point (numeric).
34  *
35  * LEGACY: VIRT_ENTRY
36  */
37 #define XEN_ELFNOTE_ENTRY          1
38 
39 /* The virtual address of the hypercall transfer page (numeric).
40  *
41  * LEGACY: HYPERCALL_PAGE. (n.b. legacy value is a physical page
42  * number not a virtual address)
43  */
44 #define XEN_ELFNOTE_HYPERCALL_PAGE 2
45 
46 /* The virtual address where the kernel image should be mapped (numeric).
47  *
48  * Defaults to 0.
49  *
50  * LEGACY: VIRT_BASE
51  */
52 #define XEN_ELFNOTE_VIRT_BASE      3
53 
54 /*
55  * The offset of the ELF paddr field from the acutal required
56  * pseudo-physical address (numeric).
57  *
58  * This is used to maintain backwards compatibility with older kernels
59  * which wrote __PAGE_OFFSET into that field. This field defaults to 0
60  * if not present.
61  *
62  * LEGACY: ELF_PADDR_OFFSET. (n.b. legacy default is VIRT_BASE)
63  */
64 #define XEN_ELFNOTE_PADDR_OFFSET   4
65 
66 /*
67  * The version of Xen that we work with (string).
68  *
69  * LEGACY: XEN_VER
70  */
71 #define XEN_ELFNOTE_XEN_VERSION    5
72 
73 /*
74  * The name of the guest operating system (string).
75  *
76  * LEGACY: GUEST_OS
77  */
78 #define XEN_ELFNOTE_GUEST_OS       6
79 
80 /*
81  * The version of the guest operating system (string).
82  *
83  * LEGACY: GUEST_VER
84  */
85 #define XEN_ELFNOTE_GUEST_VERSION  7
86 
87 /*
88  * The loader type (string).
89  *
90  * LEGACY: LOADER
91  */
92 #define XEN_ELFNOTE_LOADER         8
93 
94 /*
95  * The kernel supports PAE (x86/32 only, string = "yes" or "no").
96  *
97  * LEGACY: PAE (n.b. The legacy interface included a provision to
98  * indicate 'extended-cr3' support allowing L3 page tables to be
99  * placed above 4G. It is assumed that any kernel new enough to use
100  * these ELF notes will include this and therefore "yes" here is
101  * equivalent to "yes[entended-cr3]" in the __xen_guest interface.
102  */
103 #define XEN_ELFNOTE_PAE_MODE       9
104 
105 /*
106  * The features supported/required by this kernel (string).
107  *
108  * The string must consist of a list of feature names (as given in
109  * features.h, without the "XENFEAT_" prefix) separated by '|'
110  * characters. If a feature is required for the kernel to function
111  * then the feature name must be preceded by a '!' character.
112  *
113  * LEGACY: FEATURES
114  */
115 #define XEN_ELFNOTE_FEATURES      10
116 
117 /*
118  * The kernel requires the symbol table to be loaded (string = "yes" or "no")
119  * LEGACY: BSD_SYMTAB (n.b. The legacy treated the presence or absence
120  * of this string as a boolean flag rather than requiring "yes" or
121  * "no".
122  */
123 #define XEN_ELFNOTE_BSD_SYMTAB    11
124 
125 /*
126  * The lowest address the hypervisor hole can begin at (numeric).
127  *
128  * This must not be set higher than HYPERVISOR_VIRT_START. Its presence
129  * also indicates to the hypervisor that the kernel can deal with the
130  * hole starting at a higher address.
131  */
132 #define XEN_ELFNOTE_HV_START_LOW  12
133 
134 /*
135  * List of maddr_t-sized mask/value pairs describing how to recognize
136  * (non-present) L1 page table entries carrying valid MFNs (numeric).
137  */
138 #define XEN_ELFNOTE_L1_MFN_VALID  13
139 
140 /*
141  * Whether or not the guest supports cooperative suspend cancellation.
142  * This is a numeric value.
143  *
144  * Default is 0
145  */
146 #define XEN_ELFNOTE_SUSPEND_CANCEL 14
147 
148 /*
149  * The (non-default) location the initial phys-to-machine map should be
150  * placed at by the hypervisor (Dom0) or the tools (DomU).
151  * The kernel must be prepared for this mapping to be established using
152  * large pages, despite such otherwise not being available to guests.
153  * The kernel must also be able to handle the page table pages used for
154  * this mapping not being accessible through the initial mapping.
155  * (Only x86-64 supports this at present.)
156  */
157 #define XEN_ELFNOTE_INIT_P2M      15
158 
159 /*
160  * Whether or not the guest can deal with being passed an initrd not
161  * mapped through its initial page tables.
162  */
163 #define XEN_ELFNOTE_MOD_START_PFN 16
164 
165 /*
166  * The features supported by this kernel (numeric).
167  *
168  * Other than XEN_ELFNOTE_FEATURES on pre-4.2 Xen, this note allows a
169  * kernel to specify support for features that older hypervisors don't
170  * know about. The set of features 4.2 and newer hypervisors will
171  * consider supported by the kernel is the combination of the sets
172  * specified through this and the string note.
173  *
174  * LEGACY: FEATURES
175  */
176 #define XEN_ELFNOTE_SUPPORTED_FEATURES 17
177 
178 /*
179  * Physical entry point into the kernel.
180  *
181  * 32bit entry point into the kernel. When requested to launch the
182  * guest kernel in a HVM container, Xen will use this entry point to
183  * launch the guest in 32bit protected mode with paging disabled.
184  * Ignored otherwise.
185  */
186 #define XEN_ELFNOTE_PHYS32_ENTRY 18
187 
188 /*
189  * The number of the highest elfnote defined.
190  */
191 #define XEN_ELFNOTE_MAX XEN_ELFNOTE_PHYS32_ENTRY
192 
193 #endif /* __XEN_PUBLIC_ELFNOTE_H__ */
194