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 */
108struct 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
128struct 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
135struct 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