1 /* SPDX-License-Identifier: GPL-2.0 */
2 /******************************************************************************
3  * arch-x86_32.h
4  *
5  * Guest OS interface to x86 32-bit Xen.
6  *
7  * Copyright (c) 2004, K A Fraser
8  */
9 
10 #ifndef _ASM_X86_XEN_INTERFACE_32_H
11 #define _ASM_X86_XEN_INTERFACE_32_H
12 
13 
14 /*
15  * These flat segments are in the Xen-private section of every GDT. Since these
16  * are also present in the initial GDT, many OSes will be able to avoid
17  * installing their own GDT.
18  */
19 #define FLAT_RING1_CS 0xe019    /* GDT index 259 */
20 #define FLAT_RING1_DS 0xe021    /* GDT index 260 */
21 #define FLAT_RING1_SS 0xe021    /* GDT index 260 */
22 #define FLAT_RING3_CS 0xe02b    /* GDT index 261 */
23 #define FLAT_RING3_DS 0xe033    /* GDT index 262 */
24 #define FLAT_RING3_SS 0xe033    /* GDT index 262 */
25 
26 #define FLAT_KERNEL_CS FLAT_RING1_CS
27 #define FLAT_KERNEL_DS FLAT_RING1_DS
28 #define FLAT_KERNEL_SS FLAT_RING1_SS
29 #define FLAT_USER_CS    FLAT_RING3_CS
30 #define FLAT_USER_DS    FLAT_RING3_DS
31 #define FLAT_USER_SS    FLAT_RING3_SS
32 
33 /* And the trap vector is... */
34 #define TRAP_INSTR "int $0x82"
35 
36 #define __MACH2PHYS_VIRT_START 0xF5800000
37 #define __MACH2PHYS_VIRT_END   0xF6800000
38 
39 #define __MACH2PHYS_SHIFT      2
40 
41 /*
42  * Virtual addresses beyond this are not modifiable by guest OSes. The
43  * machine->physical mapping table starts at this address, read-only.
44  */
45 #define __HYPERVISOR_VIRT_START 0xF5800000
46 
47 #ifndef __ASSEMBLY__
48 
49 struct cpu_user_regs {
50     uint32_t ebx;
51     uint32_t ecx;
52     uint32_t edx;
53     uint32_t esi;
54     uint32_t edi;
55     uint32_t ebp;
56     uint32_t eax;
57     uint16_t error_code;    /* private */
58     uint16_t entry_vector;  /* private */
59     uint32_t eip;
60     uint16_t cs;
61     uint8_t  saved_upcall_mask;
62     uint8_t  _pad0;
63     uint32_t eflags;        /* eflags.IF == !saved_upcall_mask */
64     uint32_t esp;
65     uint16_t ss, _pad1;
66     uint16_t es, _pad2;
67     uint16_t ds, _pad3;
68     uint16_t fs, _pad4;
69     uint16_t gs, _pad5;
70 };
71 DEFINE_GUEST_HANDLE_STRUCT(cpu_user_regs);
72 
73 typedef uint64_t tsc_timestamp_t; /* RDTSC timestamp */
74 
75 struct arch_vcpu_info {
76     unsigned long cr2;
77     unsigned long pad[5]; /* sizeof(struct vcpu_info) == 64 */
78 };
79 
80 struct xen_callback {
81 	unsigned long cs;
82 	unsigned long eip;
83 };
84 typedef struct xen_callback xen_callback_t;
85 
86 #define XEN_CALLBACK(__cs, __eip)				\
87 	((struct xen_callback){ .cs = (__cs), .eip = (unsigned long)(__eip) })
88 #endif /* !__ASSEMBLY__ */
89 
90 
91 /*
92  * Page-directory addresses above 4GB do not fit into architectural %cr3.
93  * When accessing %cr3, or equivalent field in vcpu_guest_context, guests
94  * must use the following accessor macros to pack/unpack valid MFNs.
95  *
96  * Note that Xen is using the fact that the pagetable base is always
97  * page-aligned, and putting the 12 MSB of the address into the 12 LSB
98  * of cr3.
99  */
100 #define xen_pfn_to_cr3(pfn) (((unsigned)(pfn) << 12) | ((unsigned)(pfn) >> 20))
101 #define xen_cr3_to_pfn(cr3) (((unsigned)(cr3) >> 12) | ((unsigned)(cr3) << 20))
102 
103 #endif /* _ASM_X86_XEN_INTERFACE_32_H */
104