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