1 /* SPDX-License-Identifier: MIT */
2 /*
3  * Copyright (c) 2016, Citrix Systems, Inc.
4  */
5 
6 #ifndef __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__
7 #define __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__
8 
9 /*
10  * Start of day structure passed to PVH guests and to HVM guests in %ebx.
11  *
12  * NOTE: nothing will be loaded at physical address 0, so a 0 value in any
13  * of the address fields should be treated as not present.
14  *
15  *  0 +----------------+
16  *    | magic          | Contains the magic value XEN_HVM_START_MAGIC_VALUE
17  *    |                | ("xEn3" with the 0x80 bit of the "E" set).
18  *  4 +----------------+
19  *    | version        | Version of this structure. Current version is 1. New
20  *    |                | versions are guaranteed to be backwards-compatible.
21  *  8 +----------------+
22  *    | flags          | SIF_xxx flags.
23  * 12 +----------------+
24  *    | nr_modules     | Number of modules passed to the kernel.
25  * 16 +----------------+
26  *    | modlist_paddr  | Physical address of an array of modules
27  *    |                | (layout of the structure below).
28  * 24 +----------------+
29  *    | cmdline_paddr  | Physical address of the command line,
30  *    |                | a zero-terminated ASCII string.
31  * 32 +----------------+
32  *    | rsdp_paddr     | Physical address of the RSDP ACPI data structure.
33  * 40 +----------------+
34  *    | memmap_paddr   | Physical address of the (optional) memory map. Only
35  *    |                | present in version 1 and newer of the structure.
36  * 48 +----------------+
37  *    | memmap_entries | Number of entries in the memory map table. Zero
38  *    |                | if there is no memory map being provided. Only
39  *    |                | present in version 1 and newer of the structure.
40  * 52 +----------------+
41  *    | reserved       | Version 1 and newer only.
42  * 56 +----------------+
43  *
44  * The layout of each entry in the module structure is the following:
45  *
46  *  0 +----------------+
47  *    | paddr          | Physical address of the module.
48  *  8 +----------------+
49  *    | size           | Size of the module in bytes.
50  * 16 +----------------+
51  *    | cmdline_paddr  | Physical address of the command line,
52  *    |                | a zero-terminated ASCII string.
53  * 24 +----------------+
54  *    | reserved       |
55  * 32 +----------------+
56  *
57  * The layout of each entry in the memory map table is as follows:
58  *
59  *  0 +----------------+
60  *    | addr           | Base address
61  *  8 +----------------+
62  *    | size           | Size of mapping in bytes
63  * 16 +----------------+
64  *    | type           | Type of mapping as defined between the hypervisor
65  *    |                | and guest. See XEN_HVM_MEMMAP_TYPE_* values below.
66  * 20 +----------------|
67  *    | reserved       |
68  * 24 +----------------+
69  *
70  * The address and sizes are always a 64bit little endian unsigned integer.
71  *
72  * NB: Xen on x86 will always try to place all the data below the 4GiB
73  * boundary.
74  *
75  * Version numbers of the hvm_start_info structure have evolved like this:
76  *
77  * Version 0:  Initial implementation.
78  *
79  * Version 1:  Added the memmap_paddr/memmap_entries fields (plus 4 bytes of
80  *             padding) to the end of the hvm_start_info struct. These new
81  *             fields can be used to pass a memory map to the guest. The
82  *             memory map is optional and so guests that understand version 1
83  *             of the structure must check that memmap_entries is non-zero
84  *             before trying to read the memory map.
85  */
86 #define XEN_HVM_START_MAGIC_VALUE 0x336ec578
87 
88 /*
89  * The values used in the type field of the memory map table entries are
90  * defined below and match the Address Range Types as defined in the "System
91  * Address Map Interfaces" section of the ACPI Specification. Please refer to
92  * section 15 in version 6.2 of the ACPI spec: http://uefi.org/specifications
93  */
94 #define XEN_HVM_MEMMAP_TYPE_RAM       1
95 #define XEN_HVM_MEMMAP_TYPE_RESERVED  2
96 #define XEN_HVM_MEMMAP_TYPE_ACPI      3
97 #define XEN_HVM_MEMMAP_TYPE_NVS       4
98 #define XEN_HVM_MEMMAP_TYPE_UNUSABLE  5
99 #define XEN_HVM_MEMMAP_TYPE_DISABLED  6
100 #define XEN_HVM_MEMMAP_TYPE_PMEM      7
101 
102 /*
103  * C representation of the x86/HVM start info layout.
104  *
105  * The canonical definition of this layout is above, this is just a way to
106  * represent the layout described there using C types.
107  */
108 struct hvm_start_info {
109     uint32_t magic;             /* Contains the magic value 0x336ec578       */
110                                 /* ("xEn3" with the 0x80 bit of the "E" set).*/
111     uint32_t version;           /* Version of this structure.                */
112     uint32_t flags;             /* SIF_xxx flags.                            */
113     uint32_t nr_modules;        /* Number of modules passed to the kernel.   */
114     uint64_t modlist_paddr;     /* Physical address of an array of           */
115                                 /* hvm_modlist_entry.                        */
116     uint64_t cmdline_paddr;     /* Physical address of the command line.     */
117     uint64_t rsdp_paddr;        /* Physical address of the RSDP ACPI data    */
118                                 /* structure.                                */
119     /* All following fields only present in version 1 and newer */
120     uint64_t memmap_paddr;      /* Physical address of an array of           */
121                                 /* hvm_memmap_table_entry.                   */
122     uint32_t memmap_entries;    /* Number of entries in the memmap table.    */
123                                 /* Value will be zero if there is no memory  */
124                                 /* map being provided.                       */
125     uint32_t reserved;          /* Must be zero.                             */
126 };
127 
128 struct hvm_modlist_entry {
129     uint64_t paddr;             /* Physical address of the module.           */
130     uint64_t size;              /* Size of the module in bytes.              */
131     uint64_t cmdline_paddr;     /* Physical address of the command line.     */
132     uint64_t reserved;
133 };
134 
135 struct hvm_memmap_table_entry {
136     uint64_t addr;              /* Base address of the memory region         */
137     uint64_t size;              /* Size of the memory region in bytes        */
138     uint32_t type;              /* Mapping type                              */
139     uint32_t reserved;          /* Must be zero for Version 1.               */
140 };
141 
142 #endif /* __XEN_PUBLIC_ARCH_X86_HVM_START_INFO_H__ */
143