1 /******************************************************************************
2  * arch-x86_32.h
3  *
4  * Guest OS interface to x86 Xen.
5  *
6  * Copyright (c) 2004, K A Fraser
7  */
8 
9 #ifndef _ASM_X86_XEN_INTERFACE_H
10 #define _ASM_X86_XEN_INTERFACE_H
11 
12 #ifdef __XEN__
13 #define __DEFINE_GUEST_HANDLE(name, type) \
14     typedef struct { type *p; } __guest_handle_ ## name
15 #else
16 #define __DEFINE_GUEST_HANDLE(name, type) \
17     typedef type * __guest_handle_ ## name
18 #endif
19 
20 #define DEFINE_GUEST_HANDLE_STRUCT(name) \
21 	__DEFINE_GUEST_HANDLE(name, struct name)
22 #define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
23 #define GUEST_HANDLE(name)        __guest_handle_ ## name
24 
25 #ifdef __XEN__
26 #if defined(__i386__)
27 #define set_xen_guest_handle(hnd, val)			\
28 	do {						\
29 		if (sizeof(hnd) == 8)			\
30 			*(uint64_t *)&(hnd) = 0;	\
31 		(hnd).p = val;				\
32 	} while (0)
33 #elif defined(__x86_64__)
34 #define set_xen_guest_handle(hnd, val)	do { (hnd).p = val; } while (0)
35 #endif
36 #else
37 #if defined(__i386__)
38 #define set_xen_guest_handle(hnd, val)			\
39 	do {						\
40 		if (sizeof(hnd) == 8)			\
41 			*(uint64_t *)&(hnd) = 0;	\
42 		(hnd) = val;				\
43 	} while (0)
44 #elif defined(__x86_64__)
45 #define set_xen_guest_handle(hnd, val)	do { (hnd) = val; } while (0)
46 #endif
47 #endif
48 
49 #ifndef __ASSEMBLY__
50 /* Guest handles for primitive C types. */
51 __DEFINE_GUEST_HANDLE(uchar, unsigned char);
52 __DEFINE_GUEST_HANDLE(uint,  unsigned int);
53 __DEFINE_GUEST_HANDLE(ulong, unsigned long);
54 DEFINE_GUEST_HANDLE(char);
55 DEFINE_GUEST_HANDLE(int);
56 DEFINE_GUEST_HANDLE(long);
57 DEFINE_GUEST_HANDLE(void);
58 #endif
59 
60 #ifndef HYPERVISOR_VIRT_START
61 #define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START)
62 #endif
63 
64 #define MACH2PHYS_VIRT_START  mk_unsigned_long(__MACH2PHYS_VIRT_START)
65 #define MACH2PHYS_VIRT_END    mk_unsigned_long(__MACH2PHYS_VIRT_END)
66 #define MACH2PHYS_NR_ENTRIES  ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>__MACH2PHYS_SHIFT)
67 
68 /* Maximum number of virtual CPUs in multi-processor guests. */
69 #define MAX_VIRT_CPUS 32
70 
71 /*
72  * SEGMENT DESCRIPTOR TABLES
73  */
74 /*
75  * A number of GDT entries are reserved by Xen. These are not situated at the
76  * start of the GDT because some stupid OSes export hard-coded selector values
77  * in their ABI. These hard-coded values are always near the start of the GDT,
78  * so Xen places itself out of the way, at the far end of the GDT.
79  */
80 #define FIRST_RESERVED_GDT_PAGE  14
81 #define FIRST_RESERVED_GDT_BYTE  (FIRST_RESERVED_GDT_PAGE * 4096)
82 #define FIRST_RESERVED_GDT_ENTRY (FIRST_RESERVED_GDT_BYTE / 8)
83 
84 /*
85  * Send an array of these to HYPERVISOR_set_trap_table()
86  * The privilege level specifies which modes may enter a trap via a software
87  * interrupt. On x86/64, since rings 1 and 2 are unavailable, we allocate
88  * privilege levels as follows:
89  *  Level == 0: No one may enter
90  *  Level == 1: Kernel may enter
91  *  Level == 2: Kernel may enter
92  *  Level == 3: Everyone may enter
93  */
94 #define TI_GET_DPL(_ti)		((_ti)->flags & 3)
95 #define TI_GET_IF(_ti)		((_ti)->flags & 4)
96 #define TI_SET_DPL(_ti, _dpl)	((_ti)->flags |= (_dpl))
97 #define TI_SET_IF(_ti, _if)	((_ti)->flags |= ((!!(_if))<<2))
98 
99 #ifndef __ASSEMBLY__
100 struct trap_info {
101     uint8_t       vector;  /* exception vector                              */
102     uint8_t       flags;   /* 0-3: privilege level; 4: clear event enable?  */
103     uint16_t      cs;      /* code selector                                 */
104     unsigned long address; /* code offset                                   */
105 };
106 DEFINE_GUEST_HANDLE_STRUCT(trap_info);
107 
108 struct arch_shared_info {
109     unsigned long max_pfn;                  /* max pfn that appears in table */
110     /* Frame containing list of mfns containing list of mfns containing p2m. */
111     unsigned long pfn_to_mfn_frame_list_list;
112     unsigned long nmi_reason;
113 };
114 #endif	/* !__ASSEMBLY__ */
115 
116 #ifdef CONFIG_X86_32
117 #include "interface_32.h"
118 #else
119 #include "interface_64.h"
120 #endif
121 
122 #ifndef __ASSEMBLY__
123 /*
124  * The following is all CPU context. Note that the fpu_ctxt block is filled
125  * in by FXSAVE if the CPU has feature FXSR; otherwise FSAVE is used.
126  */
127 struct vcpu_guest_context {
128     /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
129     struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
130 #define VGCF_I387_VALID (1<<0)
131 #define VGCF_HVM_GUEST  (1<<1)
132 #define VGCF_IN_KERNEL  (1<<2)
133     unsigned long flags;                    /* VGCF_* flags                 */
134     struct cpu_user_regs user_regs;         /* User-level CPU registers     */
135     struct trap_info trap_ctxt[256];        /* Virtual IDT                  */
136     unsigned long ldt_base, ldt_ents;       /* LDT (linear address, # ents) */
137     unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
138     unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only SS1/SP1)   */
139     /* NB. User pagetable on x86/64 is placed in ctrlreg[1]. */
140     unsigned long ctrlreg[8];               /* CR0-CR7 (control registers)  */
141     unsigned long debugreg[8];              /* DB0-DB7 (debug registers)    */
142 #ifdef __i386__
143     unsigned long event_callback_cs;        /* CS:EIP of event callback     */
144     unsigned long event_callback_eip;
145     unsigned long failsafe_callback_cs;     /* CS:EIP of failsafe callback  */
146     unsigned long failsafe_callback_eip;
147 #else
148     unsigned long event_callback_eip;
149     unsigned long failsafe_callback_eip;
150     unsigned long syscall_callback_eip;
151 #endif
152     unsigned long vm_assist;                /* VMASST_TYPE_* bitmap */
153 #ifdef __x86_64__
154     /* Segment base addresses. */
155     uint64_t      fs_base;
156     uint64_t      gs_base_kernel;
157     uint64_t      gs_base_user;
158 #endif
159 };
160 DEFINE_GUEST_HANDLE_STRUCT(vcpu_guest_context);
161 #endif	/* !__ASSEMBLY__ */
162 
163 /*
164  * Prefix forces emulation of some non-trapping instructions.
165  * Currently only CPUID.
166  */
167 #ifdef __ASSEMBLY__
168 #define XEN_EMULATE_PREFIX .byte 0x0f,0x0b,0x78,0x65,0x6e ;
169 #define XEN_CPUID          XEN_EMULATE_PREFIX cpuid
170 #else
171 #define XEN_EMULATE_PREFIX ".byte 0x0f,0x0b,0x78,0x65,0x6e ; "
172 #define XEN_CPUID          XEN_EMULATE_PREFIX "cpuid"
173 #endif
174 
175 #endif /* _ASM_X86_XEN_INTERFACE_H */
176