xref: /kvm-unit-tests/lib/x86/desc.h (revision 2b934609604d16126499c8acef2808d84990968f)
1 #ifndef __IDT_TEST__
2 #define __IDT_TEST__
3 
4 #include <setjmp.h>
5 
6 void setup_idt(void);
7 void setup_alt_stack(void);
8 
9 struct ex_regs {
10     unsigned long rax, rcx, rdx, rbx;
11     unsigned long dummy, rbp, rsi, rdi;
12 #ifdef __x86_64__
13     unsigned long r8, r9, r10, r11;
14     unsigned long r12, r13, r14, r15;
15 #endif
16     unsigned long vector;
17     unsigned long error_code;
18     unsigned long rip;
19     unsigned long cs;
20     unsigned long rflags;
21 };
22 
23 typedef void (*handler)(struct ex_regs *regs);
24 
25 typedef struct {
26 	u16 prev;
27 	u16 res1;
28 	u32 esp0;
29 	u16 ss0;
30 	u16 res2;
31 	u32 esp1;
32 	u16 ss1;
33 	u16 res3;
34 	u32 esp2;
35 	u16 ss2;
36 	u16 res4;
37 	u32 cr3;
38 	u32 eip;
39 	u32 eflags;
40 	u32 eax, ecx, edx, ebx, esp, ebp, esi, edi;
41 	u16 es;
42 	u16 res5;
43 	u16 cs;
44 	u16 res6;
45 	u16 ss;
46 	u16 res7;
47 	u16 ds;
48 	u16 res8;
49 	u16 fs;
50 	u16 res9;
51 	u16 gs;
52 	u16 res10;
53 	u16 ldt;
54 	u16 res11;
55 	u16 t:1;
56 	u16 res12:15;
57 	u16 iomap_base;
58 } tss32_t;
59 
60 typedef struct  __attribute__((packed)) {
61 	u32 res1;
62 	u64 rsp0;
63 	u64 rsp1;
64 	u64 rsp2;
65 	u64 res2;
66 	u64 ist1;
67 	u64 ist2;
68 	u64 ist3;
69 	u64 ist4;
70 	u64 ist5;
71 	u64 ist6;
72 	u64 ist7;
73 	u64 res3;
74 	u16 res4;
75 	u16 iomap_base;
76 } tss64_t;
77 
78 #ifdef __x86_64
79 #define ASM_TRY(catch)                                  \
80     "movl $0, %%gs:4 \n\t"                              \
81     ".pushsection .data.ex \n\t"                        \
82     ".quad 1111f, " catch "\n\t"                        \
83     ".popsection \n\t"                                  \
84     "1111:"
85 #else
86 #define ASM_TRY(catch)                                  \
87     "movl $0, %%gs:4 \n\t"                              \
88     ".pushsection .data.ex \n\t"                        \
89     ".long 1111f, " catch "\n\t"                        \
90     ".popsection \n\t"                                  \
91     "1111:"
92 #endif
93 
94 /*
95  * selector     32-bit                        64-bit
96  * 0x00         NULL descriptor               NULL descriptor
97  * 0x08         ring-0 code segment (32-bit)  ring-0 code segment (64-bit)
98  * 0x10         ring-0 data segment (32-bit)  ring-0 data segment (32/64-bit)
99  * 0x18         ring-0 code segment (P=0)     ring-0 code segment (64-bit, P=0)
100  * 0x20         intr_alt_stack TSS            ring-0 code segment (32-bit)
101  * 0x28         ring-0 code segment (16-bit)  same
102  * 0x30         ring-0 data segment (16-bit)  same
103  * 0x38 (0x3b)  ring-3 code segment (32-bit)  same
104  * 0x40 (0x43)  ring-3 data segment (32-bit)  ring-3 data segment (32/64-bit)
105  * 0x48 (0x4b)  **unused**                    ring-3 code segment (64-bit)
106  * 0x50--0x78   free to use for test cases    same
107  * 0x80         primary TSS (CPU 0)           same
108  *
109  * Note that the same segment can be used for 32-bit and 64-bit data segments
110  * (the L bit is only defined for code segments)
111  *
112  * Selectors 0x08-0x10 and 0x3b-0x4b are set up for use with the SYSCALL
113  * and SYSRET instructions.
114  */
115 
116 #define KERNEL_CS   0x08
117 #define KERNEL_DS   0x10
118 #define NP_SEL      0x18
119 #ifdef __x86_64__
120 #define KERNEL_CS32 0x20
121 #else
122 #define TSS_INTR    0x20
123 #endif
124 #define KERNEL_CS16 0x28
125 #define KERNEL_DS16 0x30
126 #define USER_CS32   0x3b
127 #define USER_DS     0x43
128 #ifdef __x86_64__
129 #define USER_CS64   0x4b
130 #endif
131 
132 /* Synonyms */
133 #define KERNEL_DS32 KERNEL_DS
134 #define USER_DS32   USER_DS
135 
136 #ifdef __x86_64__
137 #define KERNEL_CS64 KERNEL_CS
138 #define USER_CS     USER_CS64
139 #define KERNEL_DS64 KERNEL_DS
140 #define USER_DS64   USER_DS
141 #else
142 #define KERNEL_CS32 KERNEL_CS
143 #define USER_CS     USER_CS32
144 #endif
145 
146 #define FIRST_SPARE_SEL 0x50
147 #define TSS_MAIN 0x80
148 
149 typedef struct {
150     unsigned short offset0;
151     unsigned short selector;
152     unsigned short ist : 3;
153     unsigned short : 5;
154     unsigned short type : 4;
155     unsigned short : 1;
156     unsigned short dpl : 2;
157     unsigned short p : 1;
158     unsigned short offset1;
159 #ifdef __x86_64__
160     unsigned offset2;
161     unsigned reserved;
162 #endif
163 } idt_entry_t;
164 
165 typedef struct {
166 	u16 limit_low;
167 	u16 base_low;
168 	u8 base_middle;
169 	u8 access;
170 	u8 granularity;
171 	u8 base_high;
172 } gdt_entry_t;
173 
174 struct segment_desc64 {
175 	uint16_t limit1;
176 	uint16_t base1;
177 	uint8_t  base2;
178 	union {
179 		uint16_t  type_limit_flags;      /* Type and limit flags */
180 		struct {
181 			uint16_t type:4;
182 			uint16_t s:1;
183 			uint16_t dpl:2;
184 			uint16_t p:1;
185 			uint16_t limit:4;
186 			uint16_t avl:1;
187 			uint16_t l:1;
188 			uint16_t db:1;
189 			uint16_t g:1;
190 		} __attribute__((__packed__));
191 	} __attribute__((__packed__));
192 	uint8_t  base3;
193 	uint32_t base4;
194 	uint32_t zero;
195 } __attribute__((__packed__));
196 
197 #define DESC_BUSY ((uint64_t) 1 << 41)
198 
199 extern idt_entry_t boot_idt[256];
200 
201 #ifndef __x86_64__
202 extern gdt_entry_t gdt32[];
203 extern tss32_t tss;
204 extern tss32_t tss_intr;
205 void set_gdt_task_gate(u16 tss_sel, u16 sel);
206 void set_idt_task_gate(int vec, u16 sel);
207 void set_intr_task_gate(int vec, void *fn);
208 void setup_tss32(void);
209 #else
210 extern tss64_t tss;
211 #endif
212 
213 unsigned exception_vector(void);
214 int write_cr4_checking(unsigned long val);
215 unsigned exception_error_code(void);
216 bool exception_rflags_rf(void);
217 void set_idt_entry(int vec, void *addr, int dpl);
218 void set_idt_sel(int vec, u16 sel);
219 void set_idt_dpl(int vec, u16 dpl);
220 void set_gdt_entry(int sel, u32 base,  u32 limit, u8 access, u8 gran);
221 void set_intr_alt_stack(int e, void *fn);
222 void print_current_tss_info(void);
223 handler handle_exception(u8 v, handler fn);
224 void unhandled_exception(struct ex_regs *regs, bool cpu);
225 
226 bool test_for_exception(unsigned int ex, void (*trigger_func)(void *data),
227 			void *data);
228 void __set_exception_jmpbuf(jmp_buf *addr);
229 #define set_exception_jmpbuf(jmpbuf) \
230 	(setjmp(jmpbuf) ? : (__set_exception_jmpbuf(&(jmpbuf)), 0))
231 
232 static inline void *get_idt_addr(idt_entry_t *entry)
233 {
234 	uintptr_t addr = entry->offset0 | ((u32)entry->offset1 << 16);
235 #ifdef __x86_64__
236 	addr |= (u64)entry->offset2 << 32;
237 #endif
238 	return (void *)addr;
239 }
240 
241 #endif
242