xref: /illumos-gate/usr/src/uts/intel/sys/segments.h (revision e4f7ccbe1e17940fdbde623116bcc8cd761d9ffc)
1 /*
2  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
3  */
4 /*
5  * Copyright 2019 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 #endif	/* __amd64 */
183 
184 #if defined(__amd64)
185 extern void load_segment_registers(selector_t, selector_t, selector_t,
186     selector_t);	/* (alphabetical) */
187 #elif defined(__i386)
188 extern void load_segment_registers(selector_t, selector_t, selector_t,
189     selector_t, selector_t, selector_t);	/* (alphabetical) */
190 #endif	/* __i386 */
191 
192 selector_t get_cs_register();
193 
194 #if !defined(__amd64)
195 
196 /*
197  * User segment descriptors (code and data).
198  * Legacy mode 64-bits wide.
199  */
200 typedef struct user_desc {
201 	uint32_t usd_lolimit:16;	/* segment limit 15:0 */
202 	uint32_t usd_lobase:16;		/* segment base 15:0 */
203 	uint32_t usd_midbase:8;		/* segment base 23:16 */
204 	uint32_t usd_type:5;		/* segment type, includes S bit */
205 	uint32_t usd_dpl:2;		/* segment descriptor priority level */
206 	uint32_t usd_p:1;		/* segment descriptor present */
207 	uint32_t usd_hilimit:4;		/* segment limit 19:16 */
208 	uint32_t usd_avl:1;		/* available to sw, but not used */
209 	uint32_t usd_reserved:1;	/* unused, ignored */
210 	uint32_t usd_def32:1;		/* default 32 vs 16 bit operand */
211 	uint32_t usd_gran:1;		/* limit units (bytes vs pages) */
212 	uint32_t usd_hibase:8;		/* segment base 31:24 */
213 } user_desc_t;
214 
215 #define	USEGD_GETBASE(usd)		((usd)->usd_lobase |		\
216 					(usd)->usd_midbase << 16 |	\
217 					(usd)->usd_hibase << (16 + 8))
218 
219 #define	USEGD_SETBASE(usd, b)		((usd)->usd_lobase = (b),	\
220 					(usd)->usd_midbase = (b) >> 16, \
221 					(usd)->usd_hibase = (b) >> (16 + 8))
222 
223 #define	USEGD_GETLIMIT(usd)		((usd)->usd_lolimit |		\
224 					(usd)->usd_hilimit << 16)
225 
226 #define	USEGD_SETLIMIT(usd, lim)	((usd)->usd_lolimit = lim,	\
227 					(usd)->usd_hilimit = lim >> 16)
228 
229 #define	USD_TYPESHIFT			5	/* size of usd_type field */
230 
231 #else	/* __amd64 */
232 
233 /*
234  * User segment descriptors.
235  * Long mode 64-bits wide.
236  *
237  * In 32-bit compatibility mode (%cs:usd_long=0) all fields are interpreted
238  * as in legacy mode for both code and data.
239  *
240  * In 64-bit mode (%cs:usd_long=1) code segments only have the conforming
241  * bit in usd_type, usd_dpl, usd_p, usd_long and usd_def32=0. usd_def32
242  * must be zero in 64-bit mode. Setting it to 1 is reserved for future use.
243  * All other fields are loaded but ignored by hardware.
244  *
245  * 64-bit data segments only have usd_p. All other fields are loaded but
246  * ignored by hardware when in 64-bit mode.
247  */
248 typedef struct user_desc {
249 	uint64_t usd_lolimit:16;	/* segment limit 15:0 */
250 	uint64_t usd_lobase:16;		/* segment base 15:0 */
251 	uint64_t usd_midbase:8;		/* segment base 23:16 */
252 	uint64_t usd_type:5;		/* segment type, includes S bit */
253 	uint64_t usd_dpl:2;		/* segment descriptor priority level */
254 	uint64_t usd_p:1;		/* segment descriptor present */
255 	uint64_t usd_hilimit:4;		/* segment limit 19:16 */
256 	uint64_t usd_avl:1;		/* available to sw, but not used */
257 	uint64_t usd_long:1;		/* long mode (%cs only) */
258 	uint64_t usd_def32:1;		/* default 32 vs 16 bit operand */
259 	uint64_t usd_gran:1;		/* limit units (bytes vs page) */
260 	uint64_t usd_hibase:8;		/* segment base 31:24 */
261 } user_desc_t;
262 
263 #define	USEGD_GETBASE(usd)		((usd)->usd_lobase |		\
264 					(usd)->usd_midbase << 16 |	\
265 					(usd)->usd_hibase << (16 + 8))
266 
267 #define	USEGD_SETBASE(usd, b)		((usd)->usd_lobase = (b),	\
268 					(usd)->usd_midbase = (b) >> 16, \
269 					(usd)->usd_hibase = (b) >> (16 + 8))
270 
271 #define	USEGD_GETLIMIT(usd)		((usd)->usd_lolimit |		\
272 					(usd)->usd_hilimit << 16)
273 
274 #define	USEGD_SETLIMIT(usd, lim)	((usd)->usd_lolimit = lim,	\
275 					(usd)->usd_hilimit = lim >> 16)
276 
277 #define	USD_TYPESHIFT			5	/* size of usd_type field */
278 
279 #endif /* __amd64 */
280 
281 #if !defined(__amd64)
282 
283 /*
284  * System segment descriptors for LDT and TSS segments.
285  * Legacy mode 64-bits wide.
286  */
287 typedef struct system_desc {
288 	uint32_t ssd_lolimit:16;	/* segment limit 15:0 */
289 	uint32_t ssd_lobase:16;		/* segment base 15:0 */
290 	uint32_t ssd_midbase:8;		/* segment base 23:16 */
291 	uint32_t ssd_type:4;		/* segment type */
292 	uint32_t ssd_zero:1;		/* must be zero */
293 	uint32_t ssd_dpl:2;		/* segment descriptor priority level */
294 	uint32_t ssd_p:1;		/* segment descriptor present */
295 	uint32_t ssd_hilimit:4;		/* segment limit 19:16 */
296 	uint32_t ssd_avl:1;		/* available to sw, but not used */
297 	uint32_t ssd_reserved:2;	/* unused, ignored */
298 	uint32_t ssd_gran:1;		/* limit unit (bytes vs pages) */
299 	uint32_t ssd_hibase:8;		/* segment base 31:24 */
300 } system_desc_t;
301 
302 #else	/* __amd64 */
303 
304 /*
305  * System segment descriptors for LDT and TSS segments.
306  * Long mode 128-bits wide.
307  *
308  * 32-bit LDT and TSS descriptor types are redefined to 64-bit equivalents.
309  * All other legacy types are reserved and illegal.
310  */
311 typedef struct system_desc {
312 	uint64_t ssd_lolimit:16;	/* segment limit 15:0 */
313 	uint64_t ssd_lobase:16;		/* segment base 15:0 */
314 	uint64_t ssd_midbase:8;		/* segment base 23:16 */
315 	uint64_t ssd_type:4;		/* segment type */
316 	uint64_t ssd_zero1:1;		/* must be zero */
317 	uint64_t ssd_dpl:2;		/* segment descriptor priority level */
318 	uint64_t ssd_p:1;		/* segment descriptor present */
319 	uint64_t ssd_hilimit:4;		/* segment limit 19:16 */
320 	uint64_t ssd_avl:1;		/* available to sw, but not used */
321 	uint64_t ssd_resv1:2;		/* unused, ignored */
322 	uint64_t ssd_gran:1;		/* limit unit (bytes vs pages) */
323 	uint64_t ssd_hibase:8;		/* segment base 31:24 */
324 	uint64_t ssd_hi64base:32;	/* segment base 63:32 */
325 	uint64_t ssd_resv2:8;		/* unused, ignored */
326 	uint64_t ssd_zero2:5;		/* must be zero */
327 	uint64_t ssd_resv3:19;		/* unused, ignored */
328 } system_desc_t;
329 
330 #endif	/* __amd64 */
331 
332 #define	SYSSEGD_SETLIMIT(ssd, lim)	((ssd)->ssd_lolimit = lim,	\
333 					(ssd)->ssd_hilimit = lim >> 16)
334 
335 #define	SYSSEGD_GETLIMIT(ssd)		(((ssd)->ssd_hilimit << 16) |   \
336 					(ssd)->ssd_lolimit)
337 
338 #if !defined(__amd64)
339 
340 /*
341  * System gate segment descriptors for interrupt, trap, call and task gates.
342  * Legacy mode 64-bits wide.
343  */
344 typedef struct gate_desc {
345 	uint32_t sgd_looffset:16;	/* segment code offset 15:0 */
346 	uint32_t sgd_selector:16;	/* target code or task selector */
347 	uint32_t sgd_stkcpy:5;		/* number of stack wds to cpy */
348 	uint32_t sgd_resv:3;		/* unused, ignored */
349 	uint32_t sgd_type:5;		/* segment type, includes S bit */
350 	uint32_t sgd_dpl:2;		/* segment descriptor priority level */
351 	uint32_t sgd_p:1;		/* segment descriptor present */
352 	uint32_t sgd_hioffset:16;	/* code seg off 31:16 */
353 } gate_desc_t;
354 
355 #define	GATESEG_GETOFFSET(sgd)	((uintptr_t)((sgd)->sgd_looffset |	\
356 				(sgd)->sgd_hioffset << 16))
357 
358 #else	/* __amd64 */
359 
360 /*
361  * System segment descriptors for interrupt, trap and call gates.
362  * Long mode 128-bits wide.
363  *
364  * 32-bit interrupt, trap and call gate types are redefined to 64-bit
365  * equivalents. Task gates along with all other legacy types are reserved
366  * and illegal.
367  */
368 typedef struct gate_desc {
369 	uint64_t sgd_looffset:16;	/* segment code offset 15:0 */
370 	uint64_t sgd_selector:16;	/* target code or task selector */
371 	uint64_t sgd_ist:3;		/* IST table index */
372 	uint64_t sgd_resv1:5;		/* unused, ignored */
373 	uint64_t sgd_type:5;		/* segment type, includes S bit */
374 	uint64_t sgd_dpl:2;		/* segment descriptor priority level */
375 	uint64_t sgd_p:1;		/* segment descriptor present */
376 	uint64_t sgd_hioffset:16;	/* segment code offset 31:16 */
377 	uint64_t sgd_hi64offset:32;	/* segment code offset 63:32 */
378 	uint64_t sgd_resv2:8;		/* unused, ignored */
379 	uint64_t sgd_zero:5;		/* call gate only: must be zero */
380 	uint64_t sgd_resv3:19;		/* unused, ignored */
381 } gate_desc_t;
382 
383 #define	GATESEG_GETOFFSET(sgd)	((uintptr_t)((sgd)->sgd_looffset |	\
384 				(sgd)->sgd_hioffset << 16 |		\
385 				(uint64_t)((sgd)->sgd_hi64offset) << 32))
386 
387 #endif	/* __amd64 */
388 
389 /*
390  * functions for initializing and updating segment descriptors.
391  */
392 #if defined(__amd64)
393 
394 extern void set_usegd(user_desc_t *, uint_t, void *, size_t, uint_t, uint_t,
395     uint_t, uint_t);
396 
397 #elif defined(__i386)
398 
399 extern void set_usegd(user_desc_t *, void *, size_t, uint_t, uint_t,
400     uint_t, uint_t);
401 
402 #endif	/* __i386 */
403 
404 extern uint_t idt_vector_to_ist(uint_t);
405 
406 extern void set_gatesegd(gate_desc_t *, void (*)(void), selector_t,
407     uint_t, uint_t, uint_t);
408 
409 extern void set_syssegd(system_desc_t *, void *, size_t, uint_t, uint_t);
410 
411 extern void *get_ssd_base(system_desc_t *);
412 
413 extern void gdt_update_usegd(uint_t, user_desc_t *);
414 
415 extern int ldt_update_segd(user_desc_t *, user_desc_t *);
416 
417 #if defined(__xpv)
418 
419 extern int xen_idt_to_trap_info(uint_t, gate_desc_t *, void *);
420 extern void xen_idt_write(gate_desc_t *, uint_t);
421 
422 #endif	/* __xen */
423 
424 void init_boot_gdt(user_desc_t *);
425 
426 #endif	/* _ASM */
427 
428 /*
429  * Common segment parameter defintions for granularity, default
430  * operand size and operaton mode.
431  */
432 #define	SDP_BYTES	0	/* segment limit scaled to bytes */
433 #define	SDP_PAGES	1	/* segment limit scaled to pages */
434 #define	SDP_OP32	1	/* code and data default operand = 32 bits */
435 #define	SDP_LONG	1	/* long mode code segment (64 bits) */
436 #define	SDP_SHORT	0	/* compat/legacy code segment (32 bits) */
437 /*
438  * System segments and gate types.
439  *
440  * In long mode i386 32-bit ldt, tss, call, interrupt and trap gate
441  * types are redefined into 64-bit equivalents.
442  */
443 #define	SDT_SYSNULL	 0	/* system null */
444 #define	SDT_SYS286TSS	 1	/* system 286 TSS available */
445 #define	SDT_SYSLDT	 2	/* system local descriptor table */
446 #define	SDT_SYS286BSY	 3	/* system 286 TSS busy */
447 #define	SDT_SYS286CGT	 4	/* system 286 call gate */
448 #define	SDT_SYSTASKGT	 5	/* system task gate */
449 #define	SDT_SYS286IGT	 6	/* system 286 interrupt gate */
450 #define	SDT_SYS286TGT	 7	/* system 286 trap gate */
451 #define	SDT_SYSNULL2	 8	/* system null again */
452 #define	SDT_SYSTSS	 9	/* system TSS available */
453 #define	SDT_SYSNULL3	10	/* system null again */
454 #define	SDT_SYSTSSBSY	11	/* system TSS busy */
455 #define	SDT_SYSCGT	12	/* system call gate */
456 #define	SDT_SYSNULL4	13	/* system null again */
457 #define	SDT_SYSIGT	14	/* system interrupt gate */
458 #define	SDT_SYSTGT	15	/* system trap gate */
459 
460 /*
461  * Memory segment types.
462  *
463  * While in long mode expand-down, writable and accessed type field
464  * attributes are ignored. Only the conforming bit is loaded by hardware
465  * for long mode code segment descriptors.
466  */
467 #define	SDT_MEMRO	16	/* read only */
468 #define	SDT_MEMROA	17	/* read only accessed */
469 #define	SDT_MEMRW	18	/* read write */
470 #define	SDT_MEMRWA	19	/* read write accessed */
471 #define	SDT_MEMROD	20	/* read only expand dwn limit */
472 #define	SDT_MEMRODA	21	/* read only expand dwn limit accessed */
473 #define	SDT_MEMRWD	22	/* read write expand dwn limit */
474 #define	SDT_MEMRWDA	23	/* read write expand dwn limit accessed */
475 #define	SDT_MEME	24	/* execute only */
476 #define	SDT_MEMEA	25	/* execute only accessed */
477 #define	SDT_MEMER	26	/* execute read */
478 #define	SDT_MEMERA	27	/* execute read accessed */
479 #define	SDT_MEMEC	28	/* execute only conforming */
480 #define	SDT_MEMEAC	29	/* execute only accessed conforming */
481 #define	SDT_MEMERC	30	/* execute read conforming */
482 #define	SDT_MEMERAC	31	/* execute read accessed conforming */
483 
484 /* These bits are within the "type" field, like the values above. */
485 #define	SDT_A		0x01	/* accessed bit */
486 #define	SDT_S		0x10	/* S-bit at the top of "type" for usegs */
487 
488 /*
489  * Entries in the Interrupt Descriptor Table (IDT)
490  */
491 #define	IDT_DE		0	/* #DE: Divide Error */
492 #define	IDT_DB		1	/* #DB: Debug */
493 #define	IDT_NMI		2	/* Nonmaskable External Interrupt */
494 #define	IDT_BP		3	/* #BP: Breakpoint */
495 #define	IDT_OF		4	/* #OF: Overflow */
496 #define	IDT_BR		5	/* #BR: Bound Range Exceeded */
497 #define	IDT_UD		6	/* #UD: Undefined/Invalid Opcode */
498 #define	IDT_NM		7	/* #NM: No Math Coprocessor */
499 #define	IDT_DF		8	/* #DF: Double Fault */
500 #define	IDT_FPUGP	9	/* Coprocessor Segment Overrun */
501 #define	IDT_TS		10	/* #TS: Invalid TSS */
502 #define	IDT_NP		11	/* #NP: Segment Not Present */
503 #define	IDT_SS		12	/* #SS: Stack Segment Fault */
504 #define	IDT_GP		13	/* #GP: General Protection Fault */
505 #define	IDT_PF		14	/* #PF: Page Fault */
506 #define	IDT_MF		16	/* #MF: FPU Floating-Point Error */
507 #define	IDT_AC		17	/* #AC: Alignment Check */
508 #define	IDT_MC		18	/* #MC: Machine Check */
509 #define	IDT_XF		19	/* #XF: SIMD Floating-Point Exception */
510 #define	NIDT		256	/* size in entries of IDT */
511 
512 /*
513  * Entries in the Global Descriptor Table (GDT)
514  *
515  * We make sure to space the system descriptors (LDT's, TSS')
516  * such that they are double gdt slot aligned. This is because
517  * in long mode system segment decriptors expand to 128 bits.
518  *
519  * GDT_LWPFS and GDT_LWPGS must be the same for both 32 and 64-bit
520  * kernels. See setup_context in libc. 64-bit processes must set
521  * %fs or %gs to null selector to use 64-bit fsbase or gsbase
522  * respectively.
523  */
524 #define	GDT_NULL	0	/* null */
525 #define	GDT_B32DATA	1	/* dboot 32 bit data descriptor */
526 #define	GDT_B32CODE	2	/* dboot 32 bit code descriptor */
527 #define	GDT_B16CODE	3	/* bios call 16 bit code descriptor */
528 #define	GDT_B16DATA	4	/* bios call 16 bit data descriptor */
529 #define	GDT_B64CODE	5	/* dboot 64 bit code descriptor */
530 #define	GDT_BGSTMP	7	/* kmdb descriptor only used early in boot */
531 #define	GDT_CPUID	16	/* store numeric id of current CPU */
532 
533 #if defined(__amd64)
534 
535 #define	GDT_KCODE	6	/* kernel code seg %cs */
536 #define	GDT_KDATA	7	/* kernel data seg %ds */
537 #define	GDT_U32CODE	8	/* 32-bit process on 64-bit kernel %cs */
538 #define	GDT_UDATA	9	/* user data seg %ds (32 and 64 bit) */
539 #define	GDT_UCODE	10	/* native user code  seg %cs */
540 #define	GDT_LDT		12	/* (12-13) LDT for current process */
541 #define	GDT_KTSS	14	/* (14-15) kernel tss */
542 #define	GDT_FS		GDT_NULL /* kernel %fs segment selector */
543 #define	GDT_GS		GDT_NULL /* kernel %gs segment selector */
544 #define	GDT_LWPFS	55	/* lwp private %fs segment selector (32-bit) */
545 #define	GDT_LWPGS	56	/* lwp private %gs segment selector (32-bit) */
546 #define	GDT_BRANDMIN	57	/* first entry in GDT for brand usage */
547 #define	GDT_BRANDMAX	61	/* last entry in GDT for brand usage */
548 #define	NGDT		62	/* number of entries in GDT */
549 
550 /*
551  * This selector is only used in the temporary GDT used to bring additional
552  * CPUs from 16-bit real mode into long mode in real_mode_start().
553  */
554 #define	TEMPGDT_KCODE64	1	/* 64-bit code selector */
555 
556 #elif defined(__i386)
557 
558 #define	GDT_LDT		40	/* LDT for current process */
559 #define	GDT_KTSS	42	/* kernel tss */
560 #define	GDT_KCODE	43	/* kernel code seg %cs */
561 #define	GDT_KDATA	44	/* kernel data seg %ds */
562 #define	GDT_UCODE	45	/* native user code  seg %cs */
563 #define	GDT_UDATA	46	/* user data seg %ds (32 and 64 bit) */
564 #define	GDT_DBFLT	47	/* double fault #DF selector */
565 #define	GDT_FS		53	/* kernel %fs segment selector */
566 #define	GDT_GS		54	/* kernel %gs segment selector */
567 #define	GDT_LWPFS	55	/* lwp private %fs segment selector */
568 #define	GDT_LWPGS	56	/* lwp private %gs segment selector */
569 #define	GDT_BRANDMIN	57	/* first entry in GDT for brand usage */
570 #define	GDT_BRANDMAX	61	/* last entry in GDT for brand usage */
571 #if !defined(__xpv)
572 #define	NGDT		90	/* number of entries in GDT */
573 #else
574 #define	NGDT		512	/* single 4K page for the hypervisor */
575 #endif
576 
577 #endif	/* __i386 */
578 
579 /*
580  * Convenient selector definitions.
581  */
582 
583 /*
584  * XXPV	64 bit Xen only allows the guest %cs/%ss be the private ones it
585  * provides, not the ones we create for ourselves.  See FLAT_RING3_CS64 in
586  * public/arch-x86_64.h
587  *
588  * 64-bit Xen runs paravirtual guests in ring 3 but emulates them running in
589  * ring 0 by clearing CPL in %cs value pushed on guest exception stacks.
590  * Therefore we will have KCS_SEL value indicate ring 0 and use that everywhere
591  * in the kernel. But in the few files where we initialize segment registers or
592  * create and update descriptors we will explicity OR in SEL_KPL (ring 3) for
593  * kernel %cs. See desctbls.c for an example.
594  */
595 
596 #if defined(__xpv) && defined(__amd64)
597 #define	KCS_SEL		0xe030		/* FLAT_RING3_CS64 & 0xFFF0 */
598 #define	KDS_SEL		0xe02b		/* FLAT_RING3_SS64 */
599 #else
600 #define	KCS_SEL		SEL_GDT(GDT_KCODE, SEL_KPL)
601 #define	KDS_SEL		SEL_GDT(GDT_KDATA, SEL_KPL)
602 #endif
603 
604 #define	UCS_SEL		SEL_GDT(GDT_UCODE, SEL_UPL)
605 #if defined(__amd64)
606 #define	TEMP_CS64_SEL	SEL_GDT(TEMPGDT_KCODE64, SEL_KPL)
607 #define	U32CS_SEL	SEL_GDT(GDT_U32CODE, SEL_UPL)
608 #endif
609 
610 #define	UDS_SEL		SEL_GDT(GDT_UDATA, SEL_UPL)
611 #define	ULDT_SEL	SEL_GDT(GDT_LDT, SEL_KPL)
612 #define	KTSS_SEL	SEL_GDT(GDT_KTSS, SEL_KPL)
613 #define	DFTSS_SEL	SEL_GDT(GDT_DBFLT, SEL_KPL)
614 #define	KFS_SEL		0
615 #define	KGS_SEL		SEL_GDT(GDT_GS, SEL_KPL)
616 #define	LWPFS_SEL	SEL_GDT(GDT_LWPFS, SEL_UPL)
617 #define	LWPGS_SEL	SEL_GDT(GDT_LWPGS, SEL_UPL)
618 #define	BRANDMIN_SEL	SEL_GDT(GDT_BRANDMIN, SEL_UPL)
619 #define	BRANDMAX_SEL	SEL_GDT(GDT_BRANDMAX, SEL_UPL)
620 
621 #define	B64CODE_SEL	SEL_GDT(GDT_B64CODE, SEL_KPL)
622 #define	B32CODE_SEL	SEL_GDT(GDT_B32CODE, SEL_KPL)
623 #define	B32DATA_SEL	SEL_GDT(GDT_B32DATA, SEL_KPL)
624 #define	B16CODE_SEL	SEL_GDT(GDT_B16CODE, SEL_KPL)
625 #define	B16DATA_SEL	SEL_GDT(GDT_B16DATA, SEL_KPL)
626 
627 /*
628  * Temporary %gs descriptor used by kmdb with -d option. Only lives
629  * in boot's GDT and is not copied into kernel's GDT from boot.
630  */
631 #define	KMDBGS_SEL	SEL_GDT(GDT_BGSTMP, SEL_KPL)
632 
633 /*
634  * Selector used for kdi_idt when kmdb has taken over the IDT.
635  */
636 #if defined(__amd64)
637 #define	KMDBCODE_SEL	B64CODE_SEL
638 #else
639 #define	KMDBCODE_SEL	B32CODE_SEL
640 #endif
641 
642 /*
643  * Entries in default Local Descriptor Table (LDT) for every process.
644  */
645 #define	LDT_SYSCALL	0	/* call gate for libc.a (obsolete) */
646 #define	LDT_SIGCALL	1	/* EOL me, call gate for static sigreturn */
647 #define	LDT_RESVD1	2	/* old user %cs */
648 #define	LDT_RESVD2	3	/* old user %ds */
649 #define	LDT_ALTSYSCALL	4	/* alternate call gate for system calls */
650 #define	LDT_ALTSIGCALL	5	/* EOL me, alternate call gate for sigreturn */
651 #define	LDT_UDBASE	6	/* user descriptor base index */
652 #define	MINNLDT		512	/* Current min solaris ldt size (1 4K page) */
653 #define	MAXNLDT		8192	/* max solaris ldt size (16 4K pages) */
654 
655 #ifdef _KERNEL
656 #define	LDT_CPU_SIZE	(16 * 4096)	/* Size of kernel per-CPU allocation */
657 #endif
658 
659 #ifndef	_ASM
660 
661 extern	gate_desc_t	*idt0;
662 extern	desctbr_t	idt0_default_reg;
663 extern	user_desc_t	*gdt0;
664 
665 extern user_desc_t	zero_udesc;
666 extern user_desc_t	null_udesc;
667 extern system_desc_t	null_sdesc;
668 
669 #if defined(__amd64)
670 extern user_desc_t	zero_u32desc;
671 #endif
672 #if defined(__amd64)
673 extern user_desc_t	ucs_on;
674 extern user_desc_t	ucs_off;
675 extern user_desc_t	ucs32_on;
676 extern user_desc_t	ucs32_off;
677 #endif  /* __amd64 */
678 
679 extern tss_t *ktss0;
680 
681 #if defined(__i386)
682 extern tss_t *dftss0;
683 #endif	/* __i386 */
684 
685 extern void div0trap(), dbgtrap(), nmiint(), brktrap(), ovflotrap();
686 extern void boundstrap(), invoptrap(), ndptrap();
687 #if !defined(__xpv)
688 extern void syserrtrap();
689 #endif
690 extern void invaltrap(), invtsstrap(), segnptrap(), stktrap();
691 extern void gptrap(), pftrap(), ndperr();
692 extern void overrun(), resvtrap();
693 extern void _start(), cmnint();
694 extern void achktrap(), mcetrap();
695 extern void xmtrap();
696 extern void fasttrap();
697 extern void dtrace_ret();
698 
699 /* KPTI trampolines */
700 extern void tr_invaltrap();
701 extern void tr_div0trap(), tr_dbgtrap(), tr_nmiint(), tr_brktrap();
702 extern void tr_ovflotrap(), tr_boundstrap(), tr_invoptrap(), tr_ndptrap();
703 #if !defined(__xpv)
704 extern void tr_syserrtrap();
705 #endif
706 extern void tr_invaltrap(), tr_invtsstrap(), tr_segnptrap(), tr_stktrap();
707 extern void tr_gptrap(), tr_pftrap(), tr_ndperr();
708 extern void tr_overrun(), tr_resvtrap();
709 extern void tr_achktrap(), tr_mcetrap();
710 extern void tr_xmtrap();
711 extern void tr_fasttrap();
712 extern void tr_dtrace_ret();
713 
714 #if !defined(__amd64)
715 extern void pentium_pftrap();
716 #endif
717 
718 extern uint64_t kpti_enable;
719 
720 #endif /* _ASM */
721 
722 #ifdef	__cplusplus
723 }
724 #endif
725 
726 #endif /* _SYS_SEGMENTS_H */
727