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