xref: /illumos-gate/usr/src/uts/intel/sys/segments.h (revision 553e44ce7e541a9e1404b1ead92be0753668710a)
1 /*
2  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
3  */
4 /*
5  * Copyright 2018 Joyent, Inc.
6  */
7 
8 #ifndef	_SYS_SEGMENTS_H
9 #define	_SYS_SEGMENTS_H
10 
11 #ifdef	__cplusplus
12 extern "C" {
13 #endif
14 
15 /*
16  * Copyright (c) 1989, 1990 William F. Jolitz
17  * Copyright (c) 1990 The Regents of the University of California.
18  * All rights reserved.
19  *
20  * This code is derived from software contributed to Berkeley by
21  * William Jolitz.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the above copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *	This product includes software developed by the University of
34  *	California, Berkeley and its contributors.
35  * 4. Neither the name of the University nor the names of its contributors
36  *    may be used to endorse or promote products derived from this software
37  *    without specific prior written permission.
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
40  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
42  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
43  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
44  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
45  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
46  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
47  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
48  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
49  * SUCH DAMAGE.
50  *
51  *	from: @(#)segments.h	7.1 (Berkeley) 5/9/91
52  * $FreeBSD: src/sys/i386/include/segments.h,v 1.34 2003/09/10 01:07:04
53  * jhb Exp $
54  *
55  * 386 Segmentation Data Structures and definitions
56  *	William F. Jolitz (william@ernie.berkeley.edu) 6/20/1989
57  */
58 
59 #include <sys/tss.h>
60 
61 /*
62  * Selector register format
63  * CS, DS, ES, FS, GS, SS
64  *
65  *  15                  3  2  1 0
66  * +---------------------+---+----+
67  * |          SI         |TI |RPL |
68  * +---------------------+---+----+
69  *
70  * SI  = selector index
71  * TI  = table indicator (0 = GDT, 1 = LDT)
72  * RPL = requestor privilege level
73  */
74 #if !defined(_ASM) || defined(__GNUC_AS__)
75 #define	IDXTOSEL(s)	((s) << 3)		/* index to selector */
76 #define	SEL_GDT(s, r)	(IDXTOSEL(s) | r)	/* global sel */
77 #else
78 #define	IDXTOSEL(s)	[s << 3]
79 #define	SEL_GDT(s, r)	[IDXTOSEL(s) | r]
80 #endif
81 
82 #define	SELTOIDX(s)	((s) >> 3)	/* selector to index */
83 
84 /*
85  * SEL_(KPL,UPL,XPL) is the RPL or DPL value for code and data selectors
86  * and their descriptors respectively.
87  *
88  * TRP_(KPL,UPL,XPL) is used to indicate the DPL for system gates only.
89  *
90  * This distinction is important to support para-virt guests on the
91  * 64-bit hypervisor. Both guest kernel and user run in ring 3 and the
92  * hypervisor runs in ring 0. When the kernel creates its trap and
93  * interrupt gates it needs a way to prevent any arbitrary int $n
94  * instruction from entering a gate that is not expected. The hypervisor
95  * allows these gates to have a DPL from 1 to 3. By creating gates
96  * with a DPL below user (ring 3) the int $n will generate a #gp fault
97  * which the hypervisor catches and forwards to the guest.
98  */
99 #if defined(__xpv)
100 
101 #define	SEL_XPL		0		/* hypervisor privilege level */
102 #define	SEL_KPL		3		/* both kernel and user in ring 3 */
103 #define	TRP_KPL		1		/* system gate priv (user blocked) */
104 #define	TRP_XPL		0		/* system gate priv (hypervisor) */
105 
106 #define	IST_DBG		0
107 
108 #else	/* __xpv */
109 
110 #define	SEL_KPL		0		/* kernel privilege level on metal */
111 #define	TRP_KPL		SEL_KPL		/* system gate priv (user blocked) */
112 
113 
114 #define	IST_DF		1
115 #define	IST_NMI		2
116 #define	IST_MCE		3
117 #define	IST_DBG		4
118 #define	IST_NESTABLE	5
119 #define	IST_DEFAULT	6
120 
121 #endif	/* __xpv */
122 
123 #define	IST_NONE	0
124 
125 #define	SEL_UPL		3		/* user priority level */
126 #define	TRP_UPL		3		/* system gate priv (user allowed) */
127 #define	SEL_TI_LDT	4		/* local descriptor table */
128 #define	SEL_LDT(s)	(IDXTOSEL(s) | SEL_TI_LDT | SEL_UPL)	/* local sel */
129 #define	CPL_MASK	3		/* RPL mask for selector */
130 #define	SELISLDT(s)	(((s) & SEL_TI_LDT) == SEL_TI_LDT)
131 #define	SELISUPL(s)	(((s) & CPL_MASK) == SEL_UPL)
132 
133 #ifndef	_ASM
134 
135 typedef	uint16_t	selector_t;	/* selector reigster */
136 
137 /*
138  * Hardware descriptor table register format for GDT and IDT.
139  */
140 #if defined(__amd64)
141 
142 #pragma pack(2)
143 typedef struct {
144 	uint16_t dtr_limit;	/* table limit */
145 	uint64_t dtr_base;	/* table base address  */
146 } desctbr_t;
147 #pragma	pack()
148 
149 #elif defined(__i386)
150 
151 #pragma pack(2)
152 typedef struct {
153 	uint16_t dtr_limit;	/* table limit */
154 	uint32_t dtr_base;	/* table base address  */
155 } desctbr_t;
156 #pragma	pack()
157 
158 #endif	/* __i386 */
159 
160 /*
161  * Functions for loading and storing descriptor table
162  * registers.
163  */
164 extern void rd_idtr(desctbr_t *);
165 extern void wr_idtr(desctbr_t *);
166 extern void rd_gdtr(desctbr_t *);
167 extern void wr_gdtr(desctbr_t *);
168 extern void wr_ldtr(selector_t);
169 extern selector_t rd_ldtr(void);
170 extern void wr_tsr(selector_t);
171 extern void kmdb_enter(void);
172 
173 #if defined(__amd64)
174 
175 /*
176  * inlines for update_segregs
177  */
178 extern void __set_ds(selector_t);
179 extern void __set_es(selector_t);
180 extern void __set_fs(selector_t);
181 extern void __set_gs(selector_t);
182 extern void __swapgs(void);
183 #endif	/* __amd64 */
184 
185 #if defined(__amd64)
186 extern void load_segment_registers(selector_t, selector_t, selector_t,
187     selector_t);	/* (alphabetical) */
188 #elif defined(__i386)
189 extern void load_segment_registers(selector_t, selector_t, selector_t,
190     selector_t, selector_t, selector_t);	/* (alphabetical) */
191 #endif	/* __i386 */
192 
193 selector_t get_cs_register();
194 
195 #if !defined(__amd64)
196 
197 /*
198  * User segment descriptors (code and data).
199  * Legacy mode 64-bits wide.
200  */
201 typedef struct user_desc {
202 	uint32_t usd_lolimit:16;	/* segment limit 15:0 */
203 	uint32_t usd_lobase:16;		/* segment base 15:0 */
204 	uint32_t usd_midbase:8;		/* segment base 23:16 */
205 	uint32_t usd_type:5;		/* segment type, includes S bit */
206 	uint32_t usd_dpl:2;		/* segment descriptor priority level */
207 	uint32_t usd_p:1;		/* segment descriptor present */
208 	uint32_t usd_hilimit:4;		/* segment limit 19:16 */
209 	uint32_t usd_avl:1;		/* available to sw, but not used */
210 	uint32_t usd_reserved:1;	/* unused, ignored */
211 	uint32_t usd_def32:1;		/* default 32 vs 16 bit operand */
212 	uint32_t usd_gran:1;		/* limit units (bytes vs pages) */
213 	uint32_t usd_hibase:8;		/* segment base 31:24 */
214 } user_desc_t;
215 
216 #define	USEGD_GETBASE(usd)		((usd)->usd_lobase |		\
217 					(usd)->usd_midbase << 16 |	\
218 					(usd)->usd_hibase << (16 + 8))
219 
220 #define	USEGD_SETBASE(usd, b)		((usd)->usd_lobase = (b),	\
221 					(usd)->usd_midbase = (b) >> 16, \
222 					(usd)->usd_hibase = (b) >> (16 + 8))
223 
224 #define	USEGD_GETLIMIT(usd)		((usd)->usd_lolimit |		\
225 					(usd)->usd_hilimit << 16)
226 
227 #define	USEGD_SETLIMIT(usd, lim)	((usd)->usd_lolimit = lim,	\
228 					(usd)->usd_hilimit = lim >> 16)
229 
230 #define	USD_TYPESHIFT			5	/* size of usd_type field */
231 
232 #else	/* __amd64 */
233 
234 /*
235  * User segment descriptors.
236  * Long mode 64-bits wide.
237  *
238  * In 32-bit compatibility mode (%cs:usd_long=0) all fields are interpreted
239  * as in legacy mode for both code and data.
240  *
241  * In 64-bit mode (%cs:usd_long=1) code segments only have the conforming
242  * bit in usd_type, usd_dpl, usd_p, usd_long and usd_def32=0. usd_def32
243  * must be zero in 64-bit mode. Setting it to 1 is reserved for future use.
244  * All other fields are loaded but ignored by hardware.
245  *
246  * 64-bit data segments only have usd_p. All other fields are loaded but
247  * ignored by hardware when in 64-bit mode.
248  */
249 typedef struct user_desc {
250 	uint64_t usd_lolimit:16;	/* segment limit 15:0 */
251 	uint64_t usd_lobase:16;		/* segment base 15:0 */
252 	uint64_t usd_midbase:8;		/* segment base 23:16 */
253 	uint64_t usd_type:5;		/* segment type, includes S bit */
254 	uint64_t usd_dpl:2;		/* segment descriptor priority level */
255 	uint64_t usd_p:1;		/* segment descriptor present */
256 	uint64_t usd_hilimit:4;		/* segment limit 19:16 */
257 	uint64_t usd_avl:1;		/* available to sw, but not used */
258 	uint64_t usd_long:1;		/* long mode (%cs only) */
259 	uint64_t usd_def32:1;		/* default 32 vs 16 bit operand */
260 	uint64_t usd_gran:1;		/* limit units (bytes vs page) */
261 	uint64_t usd_hibase:8;		/* segment base 31:24 */
262 } user_desc_t;
263 
264 #define	USEGD_GETBASE(usd)		((usd)->usd_lobase |		\
265 					(usd)->usd_midbase << 16 |	\
266 					(usd)->usd_hibase << (16 + 8))
267 
268 #define	USEGD_SETBASE(usd, b)		((usd)->usd_lobase = (b),	\
269 					(usd)->usd_midbase = (b) >> 16, \
270 					(usd)->usd_hibase = (b) >> (16 + 8))
271 
272 #define	USEGD_GETLIMIT(usd)		((usd)->usd_lolimit |		\
273 					(usd)->usd_hilimit << 16)
274 
275 #define	USEGD_SETLIMIT(usd, lim)	((usd)->usd_lolimit = lim,	\
276 					(usd)->usd_hilimit = lim >> 16)
277 
278 #define	USD_TYPESHIFT			5	/* size of usd_type field */
279 
280 #endif /* __amd64 */
281 
282 #if !defined(__amd64)
283 
284 /*
285  * System segment descriptors for LDT and TSS segments.
286  * Legacy mode 64-bits wide.
287  */
288 typedef struct system_desc {
289 	uint32_t ssd_lolimit:16;	/* segment limit 15:0 */
290 	uint32_t ssd_lobase:16;		/* segment base 15:0 */
291 	uint32_t ssd_midbase:8;		/* segment base 23:16 */
292 	uint32_t ssd_type:4;		/* segment type */
293 	uint32_t ssd_zero:1;		/* must be zero */
294 	uint32_t ssd_dpl:2;		/* segment descriptor priority level */
295 	uint32_t ssd_p:1;		/* segment descriptor present */
296 	uint32_t ssd_hilimit:4;		/* segment limit 19:16 */
297 	uint32_t ssd_avl:1;		/* available to sw, but not used */
298 	uint32_t ssd_reserved:2;	/* unused, ignored */
299 	uint32_t ssd_gran:1;		/* limit unit (bytes vs pages) */
300 	uint32_t ssd_hibase:8;		/* segment base 31:24 */
301 } system_desc_t;
302 
303 #else	/* __amd64 */
304 
305 /*
306  * System segment descriptors for LDT and TSS segments.
307  * Long mode 128-bits wide.
308  *
309  * 32-bit LDT and TSS descriptor types are redefined to 64-bit equivalents.
310  * All other legacy types are reserved and illegal.
311  */
312 typedef struct system_desc {
313 	uint64_t ssd_lolimit:16;	/* segment limit 15:0 */
314 	uint64_t ssd_lobase:16;		/* segment base 15:0 */
315 	uint64_t ssd_midbase:8;		/* segment base 23:16 */
316 	uint64_t ssd_type:4;		/* segment type */
317 	uint64_t ssd_zero1:1;		/* must be zero */
318 	uint64_t ssd_dpl:2;		/* segment descriptor priority level */
319 	uint64_t ssd_p:1;		/* segment descriptor present */
320 	uint64_t ssd_hilimit:4;		/* segment limit 19:16 */
321 	uint64_t ssd_avl:1;		/* available to sw, but not used */
322 	uint64_t ssd_resv1:2;		/* unused, ignored */
323 	uint64_t ssd_gran:1;		/* limit unit (bytes vs pages) */
324 	uint64_t ssd_hibase:8;		/* segment base 31:24 */
325 	uint64_t ssd_hi64base:32;	/* segment base 63:32 */
326 	uint64_t ssd_resv2:8;		/* unused, ignored */
327 	uint64_t ssd_zero2:5;		/* must be zero */
328 	uint64_t ssd_resv3:19;		/* unused, ignored */
329 } system_desc_t;
330 
331 #endif	/* __amd64 */
332 
333 #define	SYSSEGD_SETLIMIT(ssd, lim)	((ssd)->ssd_lolimit = lim,	\
334 					(ssd)->ssd_hilimit = lim >> 16)
335 
336 #define	SYSSEGD_GETLIMIT(ssd)		(((ssd)->ssd_hilimit << 16) |   \
337 					(ssd)->ssd_lolimit)
338 
339 #if !defined(__amd64)
340 
341 /*
342  * System gate segment descriptors for interrupt, trap, call and task gates.
343  * Legacy mode 64-bits wide.
344  */
345 typedef struct gate_desc {
346 	uint32_t sgd_looffset:16;	/* segment code offset 15:0 */
347 	uint32_t sgd_selector:16;	/* target code or task selector */
348 	uint32_t sgd_stkcpy:5;		/* number of stack wds to cpy */
349 	uint32_t sgd_resv:3;		/* unused, ignored */
350 	uint32_t sgd_type:5;		/* segment type, includes S bit */
351 	uint32_t sgd_dpl:2;		/* segment descriptor priority level */
352 	uint32_t sgd_p:1;		/* segment descriptor present */
353 	uint32_t sgd_hioffset:16;	/* code seg off 31:16 */
354 } gate_desc_t;
355 
356 #define	GATESEG_GETOFFSET(sgd)	((uintptr_t)((sgd)->sgd_looffset |	\
357 				(sgd)->sgd_hioffset << 16))
358 
359 #else	/* __amd64 */
360 
361 /*
362  * System segment descriptors for interrupt, trap and call gates.
363  * Long mode 128-bits wide.
364  *
365  * 32-bit interrupt, trap and call gate types are redefined to 64-bit
366  * equivalents. Task gates along with all other legacy types are reserved
367  * and illegal.
368  */
369 typedef struct gate_desc {
370 	uint64_t sgd_looffset:16;	/* segment code offset 15:0 */
371 	uint64_t sgd_selector:16;	/* target code or task selector */
372 	uint64_t sgd_ist:3;		/* IST table index */
373 	uint64_t sgd_resv1:5;		/* unused, ignored */
374 	uint64_t sgd_type:5;		/* segment type, includes S bit */
375 	uint64_t sgd_dpl:2;		/* segment descriptor priority level */
376 	uint64_t sgd_p:1;		/* segment descriptor present */
377 	uint64_t sgd_hioffset:16;	/* segment code offset 31:16 */
378 	uint64_t sgd_hi64offset:32;	/* segment code offset 63:32 */
379 	uint64_t sgd_resv2:8;		/* unused, ignored */
380 	uint64_t sgd_zero:5;		/* call gate only: must be zero */
381 	uint64_t sgd_resv3:19;		/* unused, ignored */
382 } gate_desc_t;
383 
384 #define	GATESEG_GETOFFSET(sgd)	((uintptr_t)((sgd)->sgd_looffset |	\
385 				(sgd)->sgd_hioffset << 16 |		\
386 				(uint64_t)((sgd)->sgd_hi64offset) << 32))
387 
388 #endif	/* __amd64 */
389 
390 /*
391  * functions for initializing and updating segment descriptors.
392  */
393 #if defined(__amd64)
394 
395 extern void set_usegd(user_desc_t *, uint_t, void *, size_t, uint_t, uint_t,
396     uint_t, uint_t);
397 
398 #elif defined(__i386)
399 
400 extern void set_usegd(user_desc_t *, void *, size_t, uint_t, uint_t,
401     uint_t, uint_t);
402 
403 #endif	/* __i386 */
404 
405 extern uint_t idt_vector_to_ist(uint_t);
406 
407 extern void set_gatesegd(gate_desc_t *, void (*)(void), selector_t,
408     uint_t, uint_t, uint_t);
409 
410 extern void set_syssegd(system_desc_t *, void *, size_t, uint_t, uint_t);
411 
412 extern void *get_ssd_base(system_desc_t *);
413 
414 extern void gdt_update_usegd(uint_t, user_desc_t *);
415 
416 extern int ldt_update_segd(user_desc_t *, user_desc_t *);
417 
418 #if defined(__xpv)
419 
420 extern int xen_idt_to_trap_info(uint_t, gate_desc_t *, void *);
421 extern void xen_idt_write(gate_desc_t *, uint_t);
422 
423 #endif	/* __xen */
424 
425 void init_boot_gdt(user_desc_t *);
426 
427 #endif	/* _ASM */
428 
429 /*
430  * Common segment parameter defintions for granularity, default
431  * operand size and operaton mode.
432  */
433 #define	SDP_BYTES	0	/* segment limit scaled to bytes */
434 #define	SDP_PAGES	1	/* segment limit scaled to pages */
435 #define	SDP_OP32	1	/* code and data default operand = 32 bits */
436 #define	SDP_LONG	1	/* long mode code segment (64 bits) */
437 #define	SDP_SHORT	0	/* compat/legacy code segment (32 bits) */
438 /*
439  * System segments and gate types.
440  *
441  * In long mode i386 32-bit ldt, tss, call, interrupt and trap gate
442  * types are redefined into 64-bit equivalents.
443  */
444 #define	SDT_SYSNULL	 0	/* system null */
445 #define	SDT_SYS286TSS	 1	/* system 286 TSS available */
446 #define	SDT_SYSLDT	 2	/* system local descriptor table */
447 #define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
448 #define	SDT_SYS286CGT	 4	/* system 286 call gate */
449 #define	SDT_SYSTASKGT	 5	/* system task gate */
450 #define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
451 #define	SDT_SYS286TGT	 7	/* system 286 trap gate */
452 #define	SDT_SYSNULL2	 8	/* system null again */
453 #define	SDT_SYSTSS	 9	/* system TSS available */
454 #define	SDT_SYSNULL3	10	/* system null again */
455 #define	SDT_SYSTSSBSY	11	/* system TSS busy */
456 #define	SDT_SYSCGT	12	/* system call gate */
457 #define	SDT_SYSNULL4	13	/* system null again */
458 #define	SDT_SYSIGT	14	/* system interrupt gate */
459 #define	SDT_SYSTGT	15	/* system trap gate */
460 
461 /*
462  * Memory segment types.
463  *
464  * While in long mode expand-down, writable and accessed type field
465  * attributes are ignored. Only the conforming bit is loaded by hardware
466  * for long mode code segment descriptors.
467  */
468 #define	SDT_MEMRO	16	/* read only */
469 #define	SDT_MEMROA	17	/* read only accessed */
470 #define	SDT_MEMRW	18	/* read write */
471 #define	SDT_MEMRWA	19	/* read write accessed */
472 #define	SDT_MEMROD	20	/* read only expand dwn limit */
473 #define	SDT_MEMRODA	21	/* read only expand dwn limit accessed */
474 #define	SDT_MEMRWD	22	/* read write expand dwn limit */
475 #define	SDT_MEMRWDA	23	/* read write expand dwn limit accessed */
476 #define	SDT_MEME	24	/* execute only */
477 #define	SDT_MEMEA	25	/* execute only accessed */
478 #define	SDT_MEMER	26	/* execute read */
479 #define	SDT_MEMERA	27	/* execute read accessed */
480 #define	SDT_MEMEC	28	/* execute only conforming */
481 #define	SDT_MEMEAC	29	/* execute only accessed conforming */
482 #define	SDT_MEMERC	30	/* execute read conforming */
483 #define	SDT_MEMERAC	31	/* execute read accessed conforming */
484 
485 /* These bits are within the "type" field, like the values above. */
486 #define	SDT_A		0x01	/* accessed bit */
487 #define	SDT_S		0x10	/* S-bit at the top of "type" for usegs */
488 
489 /*
490  * Entries in the Interrupt Descriptor Table (IDT)
491  */
492 #define	IDT_DE		0	/* #DE: Divide Error */
493 #define	IDT_DB		1	/* #DB: Debug */
494 #define	IDT_NMI		2	/* Nonmaskable External Interrupt */
495 #define	IDT_BP		3	/* #BP: Breakpoint */
496 #define	IDT_OF		4	/* #OF: Overflow */
497 #define	IDT_BR		5	/* #BR: Bound Range Exceeded */
498 #define	IDT_UD		6	/* #UD: Undefined/Invalid Opcode */
499 #define	IDT_NM		7	/* #NM: No Math Coprocessor */
500 #define	IDT_DF		8	/* #DF: Double Fault */
501 #define	IDT_FPUGP	9	/* Coprocessor Segment Overrun */
502 #define	IDT_TS		10	/* #TS: Invalid TSS */
503 #define	IDT_NP		11	/* #NP: Segment Not Present */
504 #define	IDT_SS		12	/* #SS: Stack Segment Fault */
505 #define	IDT_GP		13	/* #GP: General Protection Fault */
506 #define	IDT_PF		14	/* #PF: Page Fault */
507 #define	IDT_MF		16	/* #MF: FPU Floating-Point Error */
508 #define	IDT_AC		17	/* #AC: Alignment Check */
509 #define	IDT_MC		18	/* #MC: Machine Check */
510 #define	IDT_XF		19	/* #XF: SIMD Floating-Point Exception */
511 #define	NIDT		256	/* size in entries of IDT */
512 
513 /*
514  * Entries in the Global Descriptor Table (GDT)
515  *
516  * We make sure to space the system descriptors (LDT's, TSS')
517  * such that they are double gdt slot aligned. This is because
518  * in long mode system segment decriptors expand to 128 bits.
519  *
520  * GDT_LWPFS and GDT_LWPGS must be the same for both 32 and 64-bit
521  * kernels. See setup_context in libc. 64-bit processes must set
522  * %fs or %gs to null selector to use 64-bit fsbase or gsbase
523  * respectively.
524  */
525 #define	GDT_NULL	0	/* null */
526 #define	GDT_B32DATA	1	/* dboot 32 bit data descriptor */
527 #define	GDT_B32CODE	2	/* dboot 32 bit code descriptor */
528 #define	GDT_B16CODE	3	/* bios call 16 bit code descriptor */
529 #define	GDT_B16DATA	4	/* bios call 16 bit data descriptor */
530 #define	GDT_B64CODE	5	/* dboot 64 bit code descriptor */
531 #define	GDT_BGSTMP	7	/* kmdb descriptor only used early in boot */
532 #define	GDT_CPUID	16	/* store numeric id of current CPU */
533 
534 #if defined(__amd64)
535 
536 #define	GDT_KCODE	6	/* kernel code seg %cs */
537 #define	GDT_KDATA	7	/* kernel data seg %ds */
538 #define	GDT_U32CODE	8	/* 32-bit process on 64-bit kernel %cs */
539 #define	GDT_UDATA	9	/* user data seg %ds (32 and 64 bit) */
540 #define	GDT_UCODE	10	/* native user code  seg %cs */
541 #define	GDT_LDT		12	/* (12-13) LDT for current process */
542 #define	GDT_KTSS	14	/* (14-15) kernel tss */
543 #define	GDT_FS		GDT_NULL /* kernel %fs segment selector */
544 #define	GDT_GS		GDT_NULL /* kernel %gs segment selector */
545 #define	GDT_LWPFS	55	/* lwp private %fs segment selector (32-bit) */
546 #define	GDT_LWPGS	56	/* lwp private %gs segment selector (32-bit) */
547 #define	GDT_BRANDMIN	57	/* first entry in GDT for brand usage */
548 #define	GDT_BRANDMAX	61	/* last entry in GDT for brand usage */
549 #define	NGDT		62	/* number of entries in GDT */
550 
551 /*
552  * This selector is only used in the temporary GDT used to bring additional
553  * CPUs from 16-bit real mode into long mode in real_mode_start().
554  */
555 #define	TEMPGDT_KCODE64	1	/* 64-bit code selector */
556 
557 #elif defined(__i386)
558 
559 #define	GDT_LDT		40	/* LDT for current process */
560 #define	GDT_KTSS	42	/* kernel tss */
561 #define	GDT_KCODE	43	/* kernel code seg %cs */
562 #define	GDT_KDATA	44	/* kernel data seg %ds */
563 #define	GDT_UCODE	45	/* native user code  seg %cs */
564 #define	GDT_UDATA	46	/* user data seg %ds (32 and 64 bit) */
565 #define	GDT_DBFLT	47	/* double fault #DF selector */
566 #define	GDT_FS		53	/* kernel %fs segment selector */
567 #define	GDT_GS		54	/* kernel %gs segment selector */
568 #define	GDT_LWPFS	55	/* lwp private %fs segment selector */
569 #define	GDT_LWPGS	56	/* lwp private %gs segment selector */
570 #define	GDT_BRANDMIN	57	/* first entry in GDT for brand usage */
571 #define	GDT_BRANDMAX	61	/* last entry in GDT for brand usage */
572 #if !defined(__xpv)
573 #define	NGDT		90	/* number of entries in GDT */
574 #else
575 #define	NGDT		512	/* single 4K page for the hypervisor */
576 #endif
577 
578 #endif	/* __i386 */
579 
580 /*
581  * Convenient selector definitions.
582  */
583 
584 /*
585  * XXPV	64 bit Xen only allows the guest %cs/%ss be the private ones it
586  * provides, not the ones we create for ourselves.  See FLAT_RING3_CS64 in
587  * public/arch-x86_64.h
588  *
589  * 64-bit Xen runs paravirtual guests in ring 3 but emulates them running in
590  * ring 0 by clearing CPL in %cs value pushed on guest exception stacks.
591  * Therefore we will have KCS_SEL value indicate ring 0 and use that everywhere
592  * in the kernel. But in the few files where we initialize segment registers or
593  * create and update descriptors we will explicity OR in SEL_KPL (ring 3) for
594  * kernel %cs. See desctbls.c for an example.
595  */
596 
597 #if defined(__xpv) && defined(__amd64)
598 #define	KCS_SEL		0xe030		/* FLAT_RING3_CS64 & 0xFFF0 */
599 #define	KDS_SEL		0xe02b		/* FLAT_RING3_SS64 */
600 #else
601 #define	KCS_SEL		SEL_GDT(GDT_KCODE, SEL_KPL)
602 #define	KDS_SEL		SEL_GDT(GDT_KDATA, SEL_KPL)
603 #endif
604 
605 #define	UCS_SEL		SEL_GDT(GDT_UCODE, SEL_UPL)
606 #if defined(__amd64)
607 #define	TEMP_CS64_SEL	SEL_GDT(TEMPGDT_KCODE64, SEL_KPL)
608 #define	U32CS_SEL	SEL_GDT(GDT_U32CODE, SEL_UPL)
609 #endif
610 
611 #define	UDS_SEL		SEL_GDT(GDT_UDATA, SEL_UPL)
612 #define	ULDT_SEL	SEL_GDT(GDT_LDT, SEL_KPL)
613 #define	KTSS_SEL	SEL_GDT(GDT_KTSS, SEL_KPL)
614 #define	DFTSS_SEL	SEL_GDT(GDT_DBFLT, SEL_KPL)
615 #define	KFS_SEL		0
616 #define	KGS_SEL		SEL_GDT(GDT_GS, SEL_KPL)
617 #define	LWPFS_SEL	SEL_GDT(GDT_LWPFS, SEL_UPL)
618 #define	LWPGS_SEL	SEL_GDT(GDT_LWPGS, SEL_UPL)
619 #define	BRANDMIN_SEL	SEL_GDT(GDT_BRANDMIN, SEL_UPL)
620 #define	BRANDMAX_SEL	SEL_GDT(GDT_BRANDMAX, SEL_UPL)
621 
622 #define	B64CODE_SEL	SEL_GDT(GDT_B64CODE, SEL_KPL)
623 #define	B32CODE_SEL	SEL_GDT(GDT_B32CODE, SEL_KPL)
624 #define	B32DATA_SEL	SEL_GDT(GDT_B32DATA, SEL_KPL)
625 #define	B16CODE_SEL	SEL_GDT(GDT_B16CODE, SEL_KPL)
626 #define	B16DATA_SEL	SEL_GDT(GDT_B16DATA, SEL_KPL)
627 
628 /*
629  * Temporary %gs descriptor used by kmdb with -d option. Only lives
630  * in boot's GDT and is not copied into kernel's GDT from boot.
631  */
632 #define	KMDBGS_SEL	SEL_GDT(GDT_BGSTMP, SEL_KPL)
633 
634 /*
635  * Selector used for kdi_idt when kmdb has taken over the IDT.
636  */
637 #if defined(__amd64)
638 #define	KMDBCODE_SEL	B64CODE_SEL
639 #else
640 #define	KMDBCODE_SEL	B32CODE_SEL
641 #endif
642 
643 /*
644  * Entries in default Local Descriptor Table (LDT) for every process.
645  */
646 #define	LDT_SYSCALL	0	/* call gate for libc.a (obsolete) */
647 #define	LDT_SIGCALL	1	/* EOL me, call gate for static sigreturn */
648 #define	LDT_RESVD1	2	/* old user %cs */
649 #define	LDT_RESVD2	3	/* old user %ds */
650 #define	LDT_ALTSYSCALL	4	/* alternate call gate for system calls */
651 #define	LDT_ALTSIGCALL	5	/* EOL me, alternate call gate for sigreturn */
652 #define	LDT_UDBASE	6	/* user descriptor base index */
653 #define	MINNLDT		512	/* Current min solaris ldt size (1 4K page) */
654 #define	MAXNLDT		8192	/* max solaris ldt size (16 4K pages) */
655 
656 #ifdef _KERNEL
657 #define	LDT_CPU_SIZE	(16 * 4096)	/* Size of kernel per-CPU allocation */
658 #endif
659 
660 #ifndef	_ASM
661 
662 extern	gate_desc_t	*idt0;
663 extern	desctbr_t	idt0_default_reg;
664 extern	user_desc_t	*gdt0;
665 
666 extern user_desc_t	zero_udesc;
667 extern user_desc_t	null_udesc;
668 extern system_desc_t	null_sdesc;
669 
670 #if defined(__amd64)
671 extern user_desc_t	zero_u32desc;
672 #endif
673 #if defined(__amd64)
674 extern user_desc_t	ucs_on;
675 extern user_desc_t	ucs_off;
676 extern user_desc_t	ucs32_on;
677 extern user_desc_t	ucs32_off;
678 #endif  /* __amd64 */
679 
680 extern tss_t *ktss0;
681 
682 #if defined(__i386)
683 extern tss_t *dftss0;
684 #endif	/* __i386 */
685 
686 extern void div0trap(), dbgtrap(), nmiint(), brktrap(), ovflotrap();
687 extern void boundstrap(), invoptrap(), ndptrap();
688 #if !defined(__xpv)
689 extern void syserrtrap();
690 #endif
691 extern void invaltrap(), invtsstrap(), segnptrap(), stktrap();
692 extern void gptrap(), pftrap(), ndperr();
693 extern void overrun(), resvtrap();
694 extern void _start(), cmnint();
695 extern void achktrap(), mcetrap();
696 extern void xmtrap();
697 extern void fasttrap();
698 extern void dtrace_ret();
699 
700 /* KPTI trampolines */
701 extern void tr_invaltrap();
702 extern void tr_div0trap(), tr_dbgtrap(), tr_nmiint(), tr_brktrap();
703 extern void tr_ovflotrap(), tr_boundstrap(), tr_invoptrap(), tr_ndptrap();
704 #if !defined(__xpv)
705 extern void tr_syserrtrap();
706 #endif
707 extern void tr_invaltrap(), tr_invtsstrap(), tr_segnptrap(), tr_stktrap();
708 extern void tr_gptrap(), tr_pftrap(), tr_ndperr();
709 extern void tr_overrun(), tr_resvtrap();
710 extern void tr_achktrap(), tr_mcetrap();
711 extern void tr_xmtrap();
712 extern void tr_fasttrap();
713 extern void tr_dtrace_ret();
714 
715 #if !defined(__amd64)
716 extern void pentium_pftrap();
717 #endif
718 
719 extern uint64_t kpti_enable;
720 
721 #endif /* _ASM */
722 
723 #ifdef	__cplusplus
724 }
725 #endif
726 
727 #endif /* _SYS_SEGMENTS_H */
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