xref: /openbmc/linux/arch/x86/include/asm/xen/hypercall.h (revision 81d67439)
1 /******************************************************************************
2  * hypercall.h
3  *
4  * Linux-specific hypervisor handling.
5  *
6  * Copyright (c) 2002-2004, K A Fraser
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License version 2
10  * as published by the Free Software Foundation; or, when distributed
11  * separately from the Linux kernel or incorporated into other
12  * software packages, subject to the following license:
13  *
14  * Permission is hereby granted, free of charge, to any person obtaining a copy
15  * of this source file (the "Software"), to deal in the Software without
16  * restriction, including without limitation the rights to use, copy, modify,
17  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
18  * and to permit persons to whom the Software is furnished to do so, subject to
19  * the following conditions:
20  *
21  * The above copyright notice and this permission notice shall be included in
22  * all copies or substantial portions of the Software.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
25  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
26  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
27  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
28  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
29  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
30  * IN THE SOFTWARE.
31  */
32 
33 #ifndef _ASM_X86_XEN_HYPERCALL_H
34 #define _ASM_X86_XEN_HYPERCALL_H
35 
36 #include <linux/kernel.h>
37 #include <linux/spinlock.h>
38 #include <linux/errno.h>
39 #include <linux/string.h>
40 #include <linux/types.h>
41 
42 #include <trace/events/xen.h>
43 
44 #include <asm/page.h>
45 #include <asm/pgtable.h>
46 
47 #include <xen/interface/xen.h>
48 #include <xen/interface/sched.h>
49 #include <xen/interface/physdev.h>
50 
51 /*
52  * The hypercall asms have to meet several constraints:
53  * - Work on 32- and 64-bit.
54  *    The two architectures put their arguments in different sets of
55  *    registers.
56  *
57  * - Work around asm syntax quirks
58  *    It isn't possible to specify one of the rNN registers in a
59  *    constraint, so we use explicit register variables to get the
60  *    args into the right place.
61  *
62  * - Mark all registers as potentially clobbered
63  *    Even unused parameters can be clobbered by the hypervisor, so we
64  *    need to make sure gcc knows it.
65  *
66  * - Avoid compiler bugs.
67  *    This is the tricky part.  Because x86_32 has such a constrained
68  *    register set, gcc versions below 4.3 have trouble generating
69  *    code when all the arg registers and memory are trashed by the
70  *    asm.  There are syntactically simpler ways of achieving the
71  *    semantics below, but they cause the compiler to crash.
72  *
73  *    The only combination I found which works is:
74  *     - assign the __argX variables first
75  *     - list all actually used parameters as "+r" (__argX)
76  *     - clobber the rest
77  *
78  * The result certainly isn't pretty, and it really shows up cpp's
79  * weakness as as macro language.  Sorry.  (But let's just give thanks
80  * there aren't more than 5 arguments...)
81  */
82 
83 extern struct { char _entry[32]; } hypercall_page[];
84 
85 #define __HYPERCALL		"call hypercall_page+%c[offset]"
86 #define __HYPERCALL_ENTRY(x)						\
87 	[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
88 
89 #ifdef CONFIG_X86_32
90 #define __HYPERCALL_RETREG	"eax"
91 #define __HYPERCALL_ARG1REG	"ebx"
92 #define __HYPERCALL_ARG2REG	"ecx"
93 #define __HYPERCALL_ARG3REG	"edx"
94 #define __HYPERCALL_ARG4REG	"esi"
95 #define __HYPERCALL_ARG5REG	"edi"
96 #else
97 #define __HYPERCALL_RETREG	"rax"
98 #define __HYPERCALL_ARG1REG	"rdi"
99 #define __HYPERCALL_ARG2REG	"rsi"
100 #define __HYPERCALL_ARG3REG	"rdx"
101 #define __HYPERCALL_ARG4REG	"r10"
102 #define __HYPERCALL_ARG5REG	"r8"
103 #endif
104 
105 #define __HYPERCALL_DECLS						\
106 	register unsigned long __res  asm(__HYPERCALL_RETREG);		\
107 	register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
108 	register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
109 	register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
110 	register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
111 	register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
112 
113 #define __HYPERCALL_0PARAM	"=r" (__res)
114 #define __HYPERCALL_1PARAM	__HYPERCALL_0PARAM, "+r" (__arg1)
115 #define __HYPERCALL_2PARAM	__HYPERCALL_1PARAM, "+r" (__arg2)
116 #define __HYPERCALL_3PARAM	__HYPERCALL_2PARAM, "+r" (__arg3)
117 #define __HYPERCALL_4PARAM	__HYPERCALL_3PARAM, "+r" (__arg4)
118 #define __HYPERCALL_5PARAM	__HYPERCALL_4PARAM, "+r" (__arg5)
119 
120 #define __HYPERCALL_0ARG()
121 #define __HYPERCALL_1ARG(a1)						\
122 	__HYPERCALL_0ARG()		__arg1 = (unsigned long)(a1);
123 #define __HYPERCALL_2ARG(a1,a2)						\
124 	__HYPERCALL_1ARG(a1)		__arg2 = (unsigned long)(a2);
125 #define __HYPERCALL_3ARG(a1,a2,a3)					\
126 	__HYPERCALL_2ARG(a1,a2)		__arg3 = (unsigned long)(a3);
127 #define __HYPERCALL_4ARG(a1,a2,a3,a4)					\
128 	__HYPERCALL_3ARG(a1,a2,a3)	__arg4 = (unsigned long)(a4);
129 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)				\
130 	__HYPERCALL_4ARG(a1,a2,a3,a4)	__arg5 = (unsigned long)(a5);
131 
132 #define __HYPERCALL_CLOBBER5	"memory"
133 #define __HYPERCALL_CLOBBER4	__HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
134 #define __HYPERCALL_CLOBBER3	__HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
135 #define __HYPERCALL_CLOBBER2	__HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
136 #define __HYPERCALL_CLOBBER1	__HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
137 #define __HYPERCALL_CLOBBER0	__HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
138 
139 #define _hypercall0(type, name)						\
140 ({									\
141 	__HYPERCALL_DECLS;						\
142 	__HYPERCALL_0ARG();						\
143 	asm volatile (__HYPERCALL					\
144 		      : __HYPERCALL_0PARAM				\
145 		      : __HYPERCALL_ENTRY(name)				\
146 		      : __HYPERCALL_CLOBBER0);				\
147 	(type)__res;							\
148 })
149 
150 #define _hypercall1(type, name, a1)					\
151 ({									\
152 	__HYPERCALL_DECLS;						\
153 	__HYPERCALL_1ARG(a1);						\
154 	asm volatile (__HYPERCALL					\
155 		      : __HYPERCALL_1PARAM				\
156 		      : __HYPERCALL_ENTRY(name)				\
157 		      : __HYPERCALL_CLOBBER1);				\
158 	(type)__res;							\
159 })
160 
161 #define _hypercall2(type, name, a1, a2)					\
162 ({									\
163 	__HYPERCALL_DECLS;						\
164 	__HYPERCALL_2ARG(a1, a2);					\
165 	asm volatile (__HYPERCALL					\
166 		      : __HYPERCALL_2PARAM				\
167 		      : __HYPERCALL_ENTRY(name)				\
168 		      : __HYPERCALL_CLOBBER2);				\
169 	(type)__res;							\
170 })
171 
172 #define _hypercall3(type, name, a1, a2, a3)				\
173 ({									\
174 	__HYPERCALL_DECLS;						\
175 	__HYPERCALL_3ARG(a1, a2, a3);					\
176 	asm volatile (__HYPERCALL					\
177 		      : __HYPERCALL_3PARAM				\
178 		      : __HYPERCALL_ENTRY(name)				\
179 		      : __HYPERCALL_CLOBBER3);				\
180 	(type)__res;							\
181 })
182 
183 #define _hypercall4(type, name, a1, a2, a3, a4)				\
184 ({									\
185 	__HYPERCALL_DECLS;						\
186 	__HYPERCALL_4ARG(a1, a2, a3, a4);				\
187 	asm volatile (__HYPERCALL					\
188 		      : __HYPERCALL_4PARAM				\
189 		      : __HYPERCALL_ENTRY(name)				\
190 		      : __HYPERCALL_CLOBBER4);				\
191 	(type)__res;							\
192 })
193 
194 #define _hypercall5(type, name, a1, a2, a3, a4, a5)			\
195 ({									\
196 	__HYPERCALL_DECLS;						\
197 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);				\
198 	asm volatile (__HYPERCALL					\
199 		      : __HYPERCALL_5PARAM				\
200 		      : __HYPERCALL_ENTRY(name)				\
201 		      : __HYPERCALL_CLOBBER5);				\
202 	(type)__res;							\
203 })
204 
205 static inline long
206 privcmd_call(unsigned call,
207 	     unsigned long a1, unsigned long a2,
208 	     unsigned long a3, unsigned long a4,
209 	     unsigned long a5)
210 {
211 	__HYPERCALL_DECLS;
212 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
213 
214 	asm volatile("call *%[call]"
215 		     : __HYPERCALL_5PARAM
216 		     : [call] "a" (&hypercall_page[call])
217 		     : __HYPERCALL_CLOBBER5);
218 
219 	return (long)__res;
220 }
221 
222 static inline int
223 HYPERVISOR_set_trap_table(struct trap_info *table)
224 {
225 	return _hypercall1(int, set_trap_table, table);
226 }
227 
228 static inline int
229 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
230 		      int *success_count, domid_t domid)
231 {
232 	return _hypercall4(int, mmu_update, req, count, success_count, domid);
233 }
234 
235 static inline int
236 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
237 		     int *success_count, domid_t domid)
238 {
239 	return _hypercall4(int, mmuext_op, op, count, success_count, domid);
240 }
241 
242 static inline int
243 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
244 {
245 	return _hypercall2(int, set_gdt, frame_list, entries);
246 }
247 
248 static inline int
249 HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
250 {
251 	return _hypercall2(int, stack_switch, ss, esp);
252 }
253 
254 #ifdef CONFIG_X86_32
255 static inline int
256 HYPERVISOR_set_callbacks(unsigned long event_selector,
257 			 unsigned long event_address,
258 			 unsigned long failsafe_selector,
259 			 unsigned long failsafe_address)
260 {
261 	return _hypercall4(int, set_callbacks,
262 			   event_selector, event_address,
263 			   failsafe_selector, failsafe_address);
264 }
265 #else  /* CONFIG_X86_64 */
266 static inline int
267 HYPERVISOR_set_callbacks(unsigned long event_address,
268 			unsigned long failsafe_address,
269 			unsigned long syscall_address)
270 {
271 	return _hypercall3(int, set_callbacks,
272 			   event_address, failsafe_address,
273 			   syscall_address);
274 }
275 #endif  /* CONFIG_X86_{32,64} */
276 
277 static inline int
278 HYPERVISOR_callback_op(int cmd, void *arg)
279 {
280 	return _hypercall2(int, callback_op, cmd, arg);
281 }
282 
283 static inline int
284 HYPERVISOR_fpu_taskswitch(int set)
285 {
286 	return _hypercall1(int, fpu_taskswitch, set);
287 }
288 
289 static inline int
290 HYPERVISOR_sched_op(int cmd, void *arg)
291 {
292 	return _hypercall2(int, sched_op, cmd, arg);
293 }
294 
295 static inline long
296 HYPERVISOR_set_timer_op(u64 timeout)
297 {
298 	unsigned long timeout_hi = (unsigned long)(timeout>>32);
299 	unsigned long timeout_lo = (unsigned long)timeout;
300 	return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
301 }
302 
303 static inline int
304 HYPERVISOR_set_debugreg(int reg, unsigned long value)
305 {
306 	return _hypercall2(int, set_debugreg, reg, value);
307 }
308 
309 static inline unsigned long
310 HYPERVISOR_get_debugreg(int reg)
311 {
312 	return _hypercall1(unsigned long, get_debugreg, reg);
313 }
314 
315 static inline int
316 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
317 {
318 	if (sizeof(u64) == sizeof(long))
319 		return _hypercall2(int, update_descriptor, ma, desc);
320 	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
321 }
322 
323 static inline int
324 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
325 {
326 	return _hypercall2(int, memory_op, cmd, arg);
327 }
328 
329 static inline int
330 HYPERVISOR_multicall(void *call_list, int nr_calls)
331 {
332 	return _hypercall2(int, multicall, call_list, nr_calls);
333 }
334 
335 static inline int
336 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
337 			     unsigned long flags)
338 {
339 	if (sizeof(new_val) == sizeof(long))
340 		return _hypercall3(int, update_va_mapping, va,
341 				   new_val.pte, flags);
342 	else
343 		return _hypercall4(int, update_va_mapping, va,
344 				   new_val.pte, new_val.pte >> 32, flags);
345 }
346 
347 static inline int
348 HYPERVISOR_event_channel_op(int cmd, void *arg)
349 {
350 	int rc = _hypercall2(int, event_channel_op, cmd, arg);
351 	if (unlikely(rc == -ENOSYS)) {
352 		struct evtchn_op op;
353 		op.cmd = cmd;
354 		memcpy(&op.u, arg, sizeof(op.u));
355 		rc = _hypercall1(int, event_channel_op_compat, &op);
356 		memcpy(arg, &op.u, sizeof(op.u));
357 	}
358 	return rc;
359 }
360 
361 static inline int
362 HYPERVISOR_xen_version(int cmd, void *arg)
363 {
364 	return _hypercall2(int, xen_version, cmd, arg);
365 }
366 
367 static inline int
368 HYPERVISOR_console_io(int cmd, int count, char *str)
369 {
370 	return _hypercall3(int, console_io, cmd, count, str);
371 }
372 
373 static inline int
374 HYPERVISOR_physdev_op(int cmd, void *arg)
375 {
376 	int rc = _hypercall2(int, physdev_op, cmd, arg);
377 	if (unlikely(rc == -ENOSYS)) {
378 		struct physdev_op op;
379 		op.cmd = cmd;
380 		memcpy(&op.u, arg, sizeof(op.u));
381 		rc = _hypercall1(int, physdev_op_compat, &op);
382 		memcpy(arg, &op.u, sizeof(op.u));
383 	}
384 	return rc;
385 }
386 
387 static inline int
388 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
389 {
390 	return _hypercall3(int, grant_table_op, cmd, uop, count);
391 }
392 
393 static inline int
394 HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
395 					 unsigned long flags, domid_t domid)
396 {
397 	if (sizeof(new_val) == sizeof(long))
398 		return _hypercall4(int, update_va_mapping_otherdomain, va,
399 				   new_val.pte, flags, domid);
400 	else
401 		return _hypercall5(int, update_va_mapping_otherdomain, va,
402 				   new_val.pte, new_val.pte >> 32,
403 				   flags, domid);
404 }
405 
406 static inline int
407 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
408 {
409 	return _hypercall2(int, vm_assist, cmd, type);
410 }
411 
412 static inline int
413 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
414 {
415 	return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
416 }
417 
418 #ifdef CONFIG_X86_64
419 static inline int
420 HYPERVISOR_set_segment_base(int reg, unsigned long value)
421 {
422 	return _hypercall2(int, set_segment_base, reg, value);
423 }
424 #endif
425 
426 static inline int
427 HYPERVISOR_suspend(unsigned long start_info_mfn)
428 {
429 	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
430 
431 	/*
432 	 * For a PV guest the tools require that the start_info mfn be
433 	 * present in rdx/edx when the hypercall is made. Per the
434 	 * hypercall calling convention this is the third hypercall
435 	 * argument, which is start_info_mfn here.
436 	 */
437 	return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
438 }
439 
440 static inline int
441 HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
442 {
443 	return _hypercall2(int, nmi_op, op, arg);
444 }
445 
446 static inline unsigned long __must_check
447 HYPERVISOR_hvm_op(int op, void *arg)
448 {
449        return _hypercall2(unsigned long, hvm_op, op, arg);
450 }
451 
452 static inline int
453 HYPERVISOR_tmem_op(
454 	struct tmem_op *op)
455 {
456 	return _hypercall1(int, tmem_op, op);
457 }
458 
459 static inline void
460 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
461 {
462 	mcl->op = __HYPERVISOR_fpu_taskswitch;
463 	mcl->args[0] = set;
464 
465 	trace_xen_mc_entry(mcl, 1);
466 }
467 
468 static inline void
469 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
470 			pte_t new_val, unsigned long flags)
471 {
472 	mcl->op = __HYPERVISOR_update_va_mapping;
473 	mcl->args[0] = va;
474 	if (sizeof(new_val) == sizeof(long)) {
475 		mcl->args[1] = new_val.pte;
476 		mcl->args[2] = flags;
477 	} else {
478 		mcl->args[1] = new_val.pte;
479 		mcl->args[2] = new_val.pte >> 32;
480 		mcl->args[3] = flags;
481 	}
482 
483 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
484 }
485 
486 static inline void
487 MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
488 		     void *uop, unsigned int count)
489 {
490 	mcl->op = __HYPERVISOR_grant_table_op;
491 	mcl->args[0] = cmd;
492 	mcl->args[1] = (unsigned long)uop;
493 	mcl->args[2] = count;
494 
495 	trace_xen_mc_entry(mcl, 3);
496 }
497 
498 static inline void
499 MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
500 				    pte_t new_val, unsigned long flags,
501 				    domid_t domid)
502 {
503 	mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
504 	mcl->args[0] = va;
505 	if (sizeof(new_val) == sizeof(long)) {
506 		mcl->args[1] = new_val.pte;
507 		mcl->args[2] = flags;
508 		mcl->args[3] = domid;
509 	} else {
510 		mcl->args[1] = new_val.pte;
511 		mcl->args[2] = new_val.pte >> 32;
512 		mcl->args[3] = flags;
513 		mcl->args[4] = domid;
514 	}
515 
516 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
517 }
518 
519 static inline void
520 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
521 			struct desc_struct desc)
522 {
523 	mcl->op = __HYPERVISOR_update_descriptor;
524 	if (sizeof(maddr) == sizeof(long)) {
525 		mcl->args[0] = maddr;
526 		mcl->args[1] = *(unsigned long *)&desc;
527 	} else {
528 		mcl->args[0] = maddr;
529 		mcl->args[1] = maddr >> 32;
530 		mcl->args[2] = desc.a;
531 		mcl->args[3] = desc.b;
532 	}
533 
534 	trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
535 }
536 
537 static inline void
538 MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
539 {
540 	mcl->op = __HYPERVISOR_memory_op;
541 	mcl->args[0] = cmd;
542 	mcl->args[1] = (unsigned long)arg;
543 
544 	trace_xen_mc_entry(mcl, 2);
545 }
546 
547 static inline void
548 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
549 		 int count, int *success_count, domid_t domid)
550 {
551 	mcl->op = __HYPERVISOR_mmu_update;
552 	mcl->args[0] = (unsigned long)req;
553 	mcl->args[1] = count;
554 	mcl->args[2] = (unsigned long)success_count;
555 	mcl->args[3] = domid;
556 
557 	trace_xen_mc_entry(mcl, 4);
558 }
559 
560 static inline void
561 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
562 		int *success_count, domid_t domid)
563 {
564 	mcl->op = __HYPERVISOR_mmuext_op;
565 	mcl->args[0] = (unsigned long)op;
566 	mcl->args[1] = count;
567 	mcl->args[2] = (unsigned long)success_count;
568 	mcl->args[3] = domid;
569 
570 	trace_xen_mc_entry(mcl, 4);
571 }
572 
573 static inline void
574 MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
575 {
576 	mcl->op = __HYPERVISOR_set_gdt;
577 	mcl->args[0] = (unsigned long)frames;
578 	mcl->args[1] = entries;
579 
580 	trace_xen_mc_entry(mcl, 2);
581 }
582 
583 static inline void
584 MULTI_stack_switch(struct multicall_entry *mcl,
585 		   unsigned long ss, unsigned long esp)
586 {
587 	mcl->op = __HYPERVISOR_stack_switch;
588 	mcl->args[0] = ss;
589 	mcl->args[1] = esp;
590 
591 	trace_xen_mc_entry(mcl, 2);
592 }
593 
594 #endif /* _ASM_X86_XEN_HYPERCALL_H */
595