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 DEFINE_GUEST_HANDLE(uint64_t);
59 DEFINE_GUEST_HANDLE(uint32_t);
60 #endif
61 
62 #ifndef HYPERVISOR_VIRT_START
63 #define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START)
64 #endif
65 
66 #define MACH2PHYS_VIRT_START  mk_unsigned_long(__MACH2PHYS_VIRT_START)
67 #define MACH2PHYS_VIRT_END    mk_unsigned_long(__MACH2PHYS_VIRT_END)
68 #define MACH2PHYS_NR_ENTRIES  ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>__MACH2PHYS_SHIFT)
69 
70 /* Maximum number of virtual CPUs in multi-processor guests. */
71 #define MAX_VIRT_CPUS 32
72 
73 /*
74  * SEGMENT DESCRIPTOR TABLES
75  */
76 /*
77  * A number of GDT entries are reserved by Xen. These are not situated at the
78  * start of the GDT because some stupid OSes export hard-coded selector values
79  * in their ABI. These hard-coded values are always near the start of the GDT,
80  * so Xen places itself out of the way, at the far end of the GDT.
81  */
82 #define FIRST_RESERVED_GDT_PAGE  14
83 #define FIRST_RESERVED_GDT_BYTE  (FIRST_RESERVED_GDT_PAGE * 4096)
84 #define FIRST_RESERVED_GDT_ENTRY (FIRST_RESERVED_GDT_BYTE / 8)
85 
86 /*
87  * Send an array of these to HYPERVISOR_set_trap_table()
88  * The privilege level specifies which modes may enter a trap via a software
89  * interrupt. On x86/64, since rings 1 and 2 are unavailable, we allocate
90  * privilege levels as follows:
91  *  Level == 0: No one may enter
92  *  Level == 1: Kernel may enter
93  *  Level == 2: Kernel may enter
94  *  Level == 3: Everyone may enter
95  */
96 #define TI_GET_DPL(_ti)		((_ti)->flags & 3)
97 #define TI_GET_IF(_ti)		((_ti)->flags & 4)
98 #define TI_SET_DPL(_ti, _dpl)	((_ti)->flags |= (_dpl))
99 #define TI_SET_IF(_ti, _if)	((_ti)->flags |= ((!!(_if))<<2))
100 
101 #ifndef __ASSEMBLY__
102 struct trap_info {
103     uint8_t       vector;  /* exception vector                              */
104     uint8_t       flags;   /* 0-3: privilege level; 4: clear event enable?  */
105     uint16_t      cs;      /* code selector                                 */
106     unsigned long address; /* code offset                                   */
107 };
108 DEFINE_GUEST_HANDLE_STRUCT(trap_info);
109 
110 struct arch_shared_info {
111     unsigned long max_pfn;                  /* max pfn that appears in table */
112     /* Frame containing list of mfns containing list of mfns containing p2m. */
113     unsigned long pfn_to_mfn_frame_list_list;
114     unsigned long nmi_reason;
115 };
116 #endif	/* !__ASSEMBLY__ */
117 
118 #ifdef CONFIG_X86_32
119 #include "interface_32.h"
120 #else
121 #include "interface_64.h"
122 #endif
123 
124 #ifndef __ASSEMBLY__
125 /*
126  * The following is all CPU context. Note that the fpu_ctxt block is filled
127  * in by FXSAVE if the CPU has feature FXSR; otherwise FSAVE is used.
128  */
129 struct vcpu_guest_context {
130     /* FPU registers come first so they can be aligned for FXSAVE/FXRSTOR. */
131     struct { char x[512]; } fpu_ctxt;       /* User-level FPU registers     */
132 #define VGCF_I387_VALID (1<<0)
133 #define VGCF_HVM_GUEST  (1<<1)
134 #define VGCF_IN_KERNEL  (1<<2)
135     unsigned long flags;                    /* VGCF_* flags                 */
136     struct cpu_user_regs user_regs;         /* User-level CPU registers     */
137     struct trap_info trap_ctxt[256];        /* Virtual IDT                  */
138     unsigned long ldt_base, ldt_ents;       /* LDT (linear address, # ents) */
139     unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
140     unsigned long kernel_ss, kernel_sp;     /* Virtual TSS (only SS1/SP1)   */
141     /* NB. User pagetable on x86/64 is placed in ctrlreg[1]. */
142     unsigned long ctrlreg[8];               /* CR0-CR7 (control registers)  */
143     unsigned long debugreg[8];              /* DB0-DB7 (debug registers)    */
144 #ifdef __i386__
145     unsigned long event_callback_cs;        /* CS:EIP of event callback     */
146     unsigned long event_callback_eip;
147     unsigned long failsafe_callback_cs;     /* CS:EIP of failsafe callback  */
148     unsigned long failsafe_callback_eip;
149 #else
150     unsigned long event_callback_eip;
151     unsigned long failsafe_callback_eip;
152     unsigned long syscall_callback_eip;
153 #endif
154     unsigned long vm_assist;                /* VMASST_TYPE_* bitmap */
155 #ifdef __x86_64__
156     /* Segment base addresses. */
157     uint64_t      fs_base;
158     uint64_t      gs_base_kernel;
159     uint64_t      gs_base_user;
160 #endif
161 };
162 DEFINE_GUEST_HANDLE_STRUCT(vcpu_guest_context);
163 #endif	/* !__ASSEMBLY__ */
164 
165 /*
166  * Prefix forces emulation of some non-trapping instructions.
167  * Currently only CPUID.
168  */
169 #ifdef __ASSEMBLY__
170 #define XEN_EMULATE_PREFIX .byte 0x0f,0x0b,0x78,0x65,0x6e ;
171 #define XEN_CPUID          XEN_EMULATE_PREFIX cpuid
172 #else
173 #define XEN_EMULATE_PREFIX ".byte 0x0f,0x0b,0x78,0x65,0x6e ; "
174 #define XEN_CPUID          XEN_EMULATE_PREFIX "cpuid"
175 #endif
176 
177 #endif /* _ASM_X86_XEN_INTERFACE_H */
178