xref: /openbmc/linux/arch/x86/include/asm/xen/hypercall.h (revision 94cdda6b)
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 #include <xen/interface/platform.h>
51 #include <xen/interface/xen-mca.h>
52 
53 /*
54  * The hypercall asms have to meet several constraints:
55  * - Work on 32- and 64-bit.
56  *    The two architectures put their arguments in different sets of
57  *    registers.
58  *
59  * - Work around asm syntax quirks
60  *    It isn't possible to specify one of the rNN registers in a
61  *    constraint, so we use explicit register variables to get the
62  *    args into the right place.
63  *
64  * - Mark all registers as potentially clobbered
65  *    Even unused parameters can be clobbered by the hypervisor, so we
66  *    need to make sure gcc knows it.
67  *
68  * - Avoid compiler bugs.
69  *    This is the tricky part.  Because x86_32 has such a constrained
70  *    register set, gcc versions below 4.3 have trouble generating
71  *    code when all the arg registers and memory are trashed by the
72  *    asm.  There are syntactically simpler ways of achieving the
73  *    semantics below, but they cause the compiler to crash.
74  *
75  *    The only combination I found which works is:
76  *     - assign the __argX variables first
77  *     - list all actually used parameters as "+r" (__argX)
78  *     - clobber the rest
79  *
80  * The result certainly isn't pretty, and it really shows up cpp's
81  * weakness as as macro language.  Sorry.  (But let's just give thanks
82  * there aren't more than 5 arguments...)
83  */
84 
85 extern struct { char _entry[32]; } hypercall_page[];
86 
87 #define __HYPERCALL		"call hypercall_page+%c[offset]"
88 #define __HYPERCALL_ENTRY(x)						\
89 	[offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
90 
91 #ifdef CONFIG_X86_32
92 #define __HYPERCALL_RETREG	"eax"
93 #define __HYPERCALL_ARG1REG	"ebx"
94 #define __HYPERCALL_ARG2REG	"ecx"
95 #define __HYPERCALL_ARG3REG	"edx"
96 #define __HYPERCALL_ARG4REG	"esi"
97 #define __HYPERCALL_ARG5REG	"edi"
98 #else
99 #define __HYPERCALL_RETREG	"rax"
100 #define __HYPERCALL_ARG1REG	"rdi"
101 #define __HYPERCALL_ARG2REG	"rsi"
102 #define __HYPERCALL_ARG3REG	"rdx"
103 #define __HYPERCALL_ARG4REG	"r10"
104 #define __HYPERCALL_ARG5REG	"r8"
105 #endif
106 
107 #define __HYPERCALL_DECLS						\
108 	register unsigned long __res  asm(__HYPERCALL_RETREG);		\
109 	register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
110 	register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
111 	register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
112 	register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
113 	register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
114 
115 #define __HYPERCALL_0PARAM	"=r" (__res)
116 #define __HYPERCALL_1PARAM	__HYPERCALL_0PARAM, "+r" (__arg1)
117 #define __HYPERCALL_2PARAM	__HYPERCALL_1PARAM, "+r" (__arg2)
118 #define __HYPERCALL_3PARAM	__HYPERCALL_2PARAM, "+r" (__arg3)
119 #define __HYPERCALL_4PARAM	__HYPERCALL_3PARAM, "+r" (__arg4)
120 #define __HYPERCALL_5PARAM	__HYPERCALL_4PARAM, "+r" (__arg5)
121 
122 #define __HYPERCALL_0ARG()
123 #define __HYPERCALL_1ARG(a1)						\
124 	__HYPERCALL_0ARG()		__arg1 = (unsigned long)(a1);
125 #define __HYPERCALL_2ARG(a1,a2)						\
126 	__HYPERCALL_1ARG(a1)		__arg2 = (unsigned long)(a2);
127 #define __HYPERCALL_3ARG(a1,a2,a3)					\
128 	__HYPERCALL_2ARG(a1,a2)		__arg3 = (unsigned long)(a3);
129 #define __HYPERCALL_4ARG(a1,a2,a3,a4)					\
130 	__HYPERCALL_3ARG(a1,a2,a3)	__arg4 = (unsigned long)(a4);
131 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)				\
132 	__HYPERCALL_4ARG(a1,a2,a3,a4)	__arg5 = (unsigned long)(a5);
133 
134 #define __HYPERCALL_CLOBBER5	"memory"
135 #define __HYPERCALL_CLOBBER4	__HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
136 #define __HYPERCALL_CLOBBER3	__HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
137 #define __HYPERCALL_CLOBBER2	__HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
138 #define __HYPERCALL_CLOBBER1	__HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
139 #define __HYPERCALL_CLOBBER0	__HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
140 
141 #define _hypercall0(type, name)						\
142 ({									\
143 	__HYPERCALL_DECLS;						\
144 	__HYPERCALL_0ARG();						\
145 	asm volatile (__HYPERCALL					\
146 		      : __HYPERCALL_0PARAM				\
147 		      : __HYPERCALL_ENTRY(name)				\
148 		      : __HYPERCALL_CLOBBER0);				\
149 	(type)__res;							\
150 })
151 
152 #define _hypercall1(type, name, a1)					\
153 ({									\
154 	__HYPERCALL_DECLS;						\
155 	__HYPERCALL_1ARG(a1);						\
156 	asm volatile (__HYPERCALL					\
157 		      : __HYPERCALL_1PARAM				\
158 		      : __HYPERCALL_ENTRY(name)				\
159 		      : __HYPERCALL_CLOBBER1);				\
160 	(type)__res;							\
161 })
162 
163 #define _hypercall2(type, name, a1, a2)					\
164 ({									\
165 	__HYPERCALL_DECLS;						\
166 	__HYPERCALL_2ARG(a1, a2);					\
167 	asm volatile (__HYPERCALL					\
168 		      : __HYPERCALL_2PARAM				\
169 		      : __HYPERCALL_ENTRY(name)				\
170 		      : __HYPERCALL_CLOBBER2);				\
171 	(type)__res;							\
172 })
173 
174 #define _hypercall3(type, name, a1, a2, a3)				\
175 ({									\
176 	__HYPERCALL_DECLS;						\
177 	__HYPERCALL_3ARG(a1, a2, a3);					\
178 	asm volatile (__HYPERCALL					\
179 		      : __HYPERCALL_3PARAM				\
180 		      : __HYPERCALL_ENTRY(name)				\
181 		      : __HYPERCALL_CLOBBER3);				\
182 	(type)__res;							\
183 })
184 
185 #define _hypercall4(type, name, a1, a2, a3, a4)				\
186 ({									\
187 	__HYPERCALL_DECLS;						\
188 	__HYPERCALL_4ARG(a1, a2, a3, a4);				\
189 	asm volatile (__HYPERCALL					\
190 		      : __HYPERCALL_4PARAM				\
191 		      : __HYPERCALL_ENTRY(name)				\
192 		      : __HYPERCALL_CLOBBER4);				\
193 	(type)__res;							\
194 })
195 
196 #define _hypercall5(type, name, a1, a2, a3, a4, a5)			\
197 ({									\
198 	__HYPERCALL_DECLS;						\
199 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);				\
200 	asm volatile (__HYPERCALL					\
201 		      : __HYPERCALL_5PARAM				\
202 		      : __HYPERCALL_ENTRY(name)				\
203 		      : __HYPERCALL_CLOBBER5);				\
204 	(type)__res;							\
205 })
206 
207 static inline long
208 privcmd_call(unsigned call,
209 	     unsigned long a1, unsigned long a2,
210 	     unsigned long a3, unsigned long a4,
211 	     unsigned long a5)
212 {
213 	__HYPERCALL_DECLS;
214 	__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
215 
216 	asm volatile("call *%[call]"
217 		     : __HYPERCALL_5PARAM
218 		     : [call] "a" (&hypercall_page[call])
219 		     : __HYPERCALL_CLOBBER5);
220 
221 	return (long)__res;
222 }
223 
224 static inline int
225 HYPERVISOR_set_trap_table(struct trap_info *table)
226 {
227 	return _hypercall1(int, set_trap_table, table);
228 }
229 
230 static inline int
231 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
232 		      int *success_count, domid_t domid)
233 {
234 	return _hypercall4(int, mmu_update, req, count, success_count, domid);
235 }
236 
237 static inline int
238 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
239 		     int *success_count, domid_t domid)
240 {
241 	return _hypercall4(int, mmuext_op, op, count, success_count, domid);
242 }
243 
244 static inline int
245 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
246 {
247 	return _hypercall2(int, set_gdt, frame_list, entries);
248 }
249 
250 static inline int
251 HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
252 {
253 	return _hypercall2(int, stack_switch, ss, esp);
254 }
255 
256 #ifdef CONFIG_X86_32
257 static inline int
258 HYPERVISOR_set_callbacks(unsigned long event_selector,
259 			 unsigned long event_address,
260 			 unsigned long failsafe_selector,
261 			 unsigned long failsafe_address)
262 {
263 	return _hypercall4(int, set_callbacks,
264 			   event_selector, event_address,
265 			   failsafe_selector, failsafe_address);
266 }
267 #else  /* CONFIG_X86_64 */
268 static inline int
269 HYPERVISOR_set_callbacks(unsigned long event_address,
270 			unsigned long failsafe_address,
271 			unsigned long syscall_address)
272 {
273 	return _hypercall3(int, set_callbacks,
274 			   event_address, failsafe_address,
275 			   syscall_address);
276 }
277 #endif  /* CONFIG_X86_{32,64} */
278 
279 static inline int
280 HYPERVISOR_callback_op(int cmd, void *arg)
281 {
282 	return _hypercall2(int, callback_op, cmd, arg);
283 }
284 
285 static inline int
286 HYPERVISOR_fpu_taskswitch(int set)
287 {
288 	return _hypercall1(int, fpu_taskswitch, set);
289 }
290 
291 static inline int
292 HYPERVISOR_sched_op(int cmd, void *arg)
293 {
294 	return _hypercall2(int, sched_op, cmd, arg);
295 }
296 
297 static inline long
298 HYPERVISOR_set_timer_op(u64 timeout)
299 {
300 	unsigned long timeout_hi = (unsigned long)(timeout>>32);
301 	unsigned long timeout_lo = (unsigned long)timeout;
302 	return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
303 }
304 
305 static inline int
306 HYPERVISOR_mca(struct xen_mc *mc_op)
307 {
308 	mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
309 	return _hypercall1(int, mca, mc_op);
310 }
311 
312 static inline int
313 HYPERVISOR_dom0_op(struct xen_platform_op *platform_op)
314 {
315 	platform_op->interface_version = XENPF_INTERFACE_VERSION;
316 	return _hypercall1(int, dom0_op, platform_op);
317 }
318 
319 static inline int
320 HYPERVISOR_set_debugreg(int reg, unsigned long value)
321 {
322 	return _hypercall2(int, set_debugreg, reg, value);
323 }
324 
325 static inline unsigned long
326 HYPERVISOR_get_debugreg(int reg)
327 {
328 	return _hypercall1(unsigned long, get_debugreg, reg);
329 }
330 
331 static inline int
332 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
333 {
334 	if (sizeof(u64) == sizeof(long))
335 		return _hypercall2(int, update_descriptor, ma, desc);
336 	return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
337 }
338 
339 static inline int
340 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
341 {
342 	return _hypercall2(int, memory_op, cmd, arg);
343 }
344 
345 static inline int
346 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
347 {
348 	return _hypercall2(int, multicall, call_list, nr_calls);
349 }
350 
351 static inline int
352 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
353 			     unsigned long flags)
354 {
355 	if (sizeof(new_val) == sizeof(long))
356 		return _hypercall3(int, update_va_mapping, va,
357 				   new_val.pte, flags);
358 	else
359 		return _hypercall4(int, update_va_mapping, va,
360 				   new_val.pte, new_val.pte >> 32, flags);
361 }
362 extern int __must_check xen_event_channel_op_compat(int, void *);
363 
364 static inline int
365 HYPERVISOR_event_channel_op(int cmd, void *arg)
366 {
367 	int rc = _hypercall2(int, event_channel_op, cmd, arg);
368 	if (unlikely(rc == -ENOSYS))
369 		rc = xen_event_channel_op_compat(cmd, arg);
370 	return rc;
371 }
372 
373 static inline int
374 HYPERVISOR_xen_version(int cmd, void *arg)
375 {
376 	return _hypercall2(int, xen_version, cmd, arg);
377 }
378 
379 static inline int
380 HYPERVISOR_console_io(int cmd, int count, char *str)
381 {
382 	return _hypercall3(int, console_io, cmd, count, str);
383 }
384 
385 extern int __must_check xen_physdev_op_compat(int, void *);
386 
387 static inline int
388 HYPERVISOR_physdev_op(int cmd, void *arg)
389 {
390 	int rc = _hypercall2(int, physdev_op, cmd, arg);
391 	if (unlikely(rc == -ENOSYS))
392 		rc = xen_physdev_op_compat(cmd, arg);
393 	return rc;
394 }
395 
396 static inline int
397 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
398 {
399 	return _hypercall3(int, grant_table_op, cmd, uop, count);
400 }
401 
402 static inline int
403 HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
404 					 unsigned long flags, domid_t domid)
405 {
406 	if (sizeof(new_val) == sizeof(long))
407 		return _hypercall4(int, update_va_mapping_otherdomain, va,
408 				   new_val.pte, flags, domid);
409 	else
410 		return _hypercall5(int, update_va_mapping_otherdomain, va,
411 				   new_val.pte, new_val.pte >> 32,
412 				   flags, domid);
413 }
414 
415 static inline int
416 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
417 {
418 	return _hypercall2(int, vm_assist, cmd, type);
419 }
420 
421 static inline int
422 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
423 {
424 	return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
425 }
426 
427 #ifdef CONFIG_X86_64
428 static inline int
429 HYPERVISOR_set_segment_base(int reg, unsigned long value)
430 {
431 	return _hypercall2(int, set_segment_base, reg, value);
432 }
433 #endif
434 
435 static inline int
436 HYPERVISOR_suspend(unsigned long start_info_mfn)
437 {
438 	struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
439 
440 	/*
441 	 * For a PV guest the tools require that the start_info mfn be
442 	 * present in rdx/edx when the hypercall is made. Per the
443 	 * hypercall calling convention this is the third hypercall
444 	 * argument, which is start_info_mfn here.
445 	 */
446 	return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
447 }
448 
449 static inline int
450 HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
451 {
452 	return _hypercall2(int, nmi_op, op, arg);
453 }
454 
455 static inline unsigned long __must_check
456 HYPERVISOR_hvm_op(int op, void *arg)
457 {
458        return _hypercall2(unsigned long, hvm_op, op, arg);
459 }
460 
461 static inline int
462 HYPERVISOR_tmem_op(
463 	struct tmem_op *op)
464 {
465 	return _hypercall1(int, tmem_op, op);
466 }
467 
468 static inline void
469 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
470 {
471 	mcl->op = __HYPERVISOR_fpu_taskswitch;
472 	mcl->args[0] = set;
473 
474 	trace_xen_mc_entry(mcl, 1);
475 }
476 
477 static inline void
478 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
479 			pte_t new_val, unsigned long flags)
480 {
481 	mcl->op = __HYPERVISOR_update_va_mapping;
482 	mcl->args[0] = va;
483 	if (sizeof(new_val) == sizeof(long)) {
484 		mcl->args[1] = new_val.pte;
485 		mcl->args[2] = flags;
486 	} else {
487 		mcl->args[1] = new_val.pte;
488 		mcl->args[2] = new_val.pte >> 32;
489 		mcl->args[3] = flags;
490 	}
491 
492 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
493 }
494 
495 static inline void
496 MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
497 		     void *uop, unsigned int count)
498 {
499 	mcl->op = __HYPERVISOR_grant_table_op;
500 	mcl->args[0] = cmd;
501 	mcl->args[1] = (unsigned long)uop;
502 	mcl->args[2] = count;
503 
504 	trace_xen_mc_entry(mcl, 3);
505 }
506 
507 static inline void
508 MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
509 				    pte_t new_val, unsigned long flags,
510 				    domid_t domid)
511 {
512 	mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
513 	mcl->args[0] = va;
514 	if (sizeof(new_val) == sizeof(long)) {
515 		mcl->args[1] = new_val.pte;
516 		mcl->args[2] = flags;
517 		mcl->args[3] = domid;
518 	} else {
519 		mcl->args[1] = new_val.pte;
520 		mcl->args[2] = new_val.pte >> 32;
521 		mcl->args[3] = flags;
522 		mcl->args[4] = domid;
523 	}
524 
525 	trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
526 }
527 
528 static inline void
529 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
530 			struct desc_struct desc)
531 {
532 	mcl->op = __HYPERVISOR_update_descriptor;
533 	if (sizeof(maddr) == sizeof(long)) {
534 		mcl->args[0] = maddr;
535 		mcl->args[1] = *(unsigned long *)&desc;
536 	} else {
537 		mcl->args[0] = maddr;
538 		mcl->args[1] = maddr >> 32;
539 		mcl->args[2] = desc.a;
540 		mcl->args[3] = desc.b;
541 	}
542 
543 	trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
544 }
545 
546 static inline void
547 MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
548 {
549 	mcl->op = __HYPERVISOR_memory_op;
550 	mcl->args[0] = cmd;
551 	mcl->args[1] = (unsigned long)arg;
552 
553 	trace_xen_mc_entry(mcl, 2);
554 }
555 
556 static inline void
557 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
558 		 int count, int *success_count, domid_t domid)
559 {
560 	mcl->op = __HYPERVISOR_mmu_update;
561 	mcl->args[0] = (unsigned long)req;
562 	mcl->args[1] = count;
563 	mcl->args[2] = (unsigned long)success_count;
564 	mcl->args[3] = domid;
565 
566 	trace_xen_mc_entry(mcl, 4);
567 }
568 
569 static inline void
570 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
571 		int *success_count, domid_t domid)
572 {
573 	mcl->op = __HYPERVISOR_mmuext_op;
574 	mcl->args[0] = (unsigned long)op;
575 	mcl->args[1] = count;
576 	mcl->args[2] = (unsigned long)success_count;
577 	mcl->args[3] = domid;
578 
579 	trace_xen_mc_entry(mcl, 4);
580 }
581 
582 static inline void
583 MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
584 {
585 	mcl->op = __HYPERVISOR_set_gdt;
586 	mcl->args[0] = (unsigned long)frames;
587 	mcl->args[1] = entries;
588 
589 	trace_xen_mc_entry(mcl, 2);
590 }
591 
592 static inline void
593 MULTI_stack_switch(struct multicall_entry *mcl,
594 		   unsigned long ss, unsigned long esp)
595 {
596 	mcl->op = __HYPERVISOR_stack_switch;
597 	mcl->args[0] = ss;
598 	mcl->args[1] = esp;
599 
600 	trace_xen_mc_entry(mcl, 2);
601 }
602 
603 #endif /* _ASM_X86_XEN_HYPERCALL_H */
604