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 #include <asm/smap.h>
47 #include <asm/nospec-branch.h>
48
49 #include <xen/interface/xen.h>
50 #include <xen/interface/sched.h>
51 #include <xen/interface/physdev.h>
52 #include <xen/interface/platform.h>
53 #include <xen/interface/xen-mca.h>
54
55 struct xen_dm_op_buf;
56
57 /*
58 * The hypercall asms have to meet several constraints:
59 * - Work on 32- and 64-bit.
60 * The two architectures put their arguments in different sets of
61 * registers.
62 *
63 * - Work around asm syntax quirks
64 * It isn't possible to specify one of the rNN registers in a
65 * constraint, so we use explicit register variables to get the
66 * args into the right place.
67 *
68 * - Mark all registers as potentially clobbered
69 * Even unused parameters can be clobbered by the hypervisor, so we
70 * need to make sure gcc knows it.
71 *
72 * - Avoid compiler bugs.
73 * This is the tricky part. Because x86_32 has such a constrained
74 * register set, gcc versions below 4.3 have trouble generating
75 * code when all the arg registers and memory are trashed by the
76 * asm. There are syntactically simpler ways of achieving the
77 * semantics below, but they cause the compiler to crash.
78 *
79 * The only combination I found which works is:
80 * - assign the __argX variables first
81 * - list all actually used parameters as "+r" (__argX)
82 * - clobber the rest
83 *
84 * The result certainly isn't pretty, and it really shows up cpp's
85 * weakness as as macro language. Sorry. (But let's just give thanks
86 * there aren't more than 5 arguments...)
87 */
88
89 extern struct { char _entry[32]; } hypercall_page[];
90
91 #define __HYPERCALL "call hypercall_page+%c[offset]"
92 #define __HYPERCALL_ENTRY(x) \
93 [offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
94
95 #ifdef CONFIG_X86_32
96 #define __HYPERCALL_RETREG "eax"
97 #define __HYPERCALL_ARG1REG "ebx"
98 #define __HYPERCALL_ARG2REG "ecx"
99 #define __HYPERCALL_ARG3REG "edx"
100 #define __HYPERCALL_ARG4REG "esi"
101 #define __HYPERCALL_ARG5REG "edi"
102 #else
103 #define __HYPERCALL_RETREG "rax"
104 #define __HYPERCALL_ARG1REG "rdi"
105 #define __HYPERCALL_ARG2REG "rsi"
106 #define __HYPERCALL_ARG3REG "rdx"
107 #define __HYPERCALL_ARG4REG "r10"
108 #define __HYPERCALL_ARG5REG "r8"
109 #endif
110
111 #define __HYPERCALL_DECLS \
112 register unsigned long __res asm(__HYPERCALL_RETREG); \
113 register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
114 register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
115 register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
116 register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
117 register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
118
119 #define __HYPERCALL_0PARAM "=r" (__res), ASM_CALL_CONSTRAINT
120 #define __HYPERCALL_1PARAM __HYPERCALL_0PARAM, "+r" (__arg1)
121 #define __HYPERCALL_2PARAM __HYPERCALL_1PARAM, "+r" (__arg2)
122 #define __HYPERCALL_3PARAM __HYPERCALL_2PARAM, "+r" (__arg3)
123 #define __HYPERCALL_4PARAM __HYPERCALL_3PARAM, "+r" (__arg4)
124 #define __HYPERCALL_5PARAM __HYPERCALL_4PARAM, "+r" (__arg5)
125
126 #define __HYPERCALL_0ARG()
127 #define __HYPERCALL_1ARG(a1) \
128 __HYPERCALL_0ARG() __arg1 = (unsigned long)(a1);
129 #define __HYPERCALL_2ARG(a1,a2) \
130 __HYPERCALL_1ARG(a1) __arg2 = (unsigned long)(a2);
131 #define __HYPERCALL_3ARG(a1,a2,a3) \
132 __HYPERCALL_2ARG(a1,a2) __arg3 = (unsigned long)(a3);
133 #define __HYPERCALL_4ARG(a1,a2,a3,a4) \
134 __HYPERCALL_3ARG(a1,a2,a3) __arg4 = (unsigned long)(a4);
135 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5) \
136 __HYPERCALL_4ARG(a1,a2,a3,a4) __arg5 = (unsigned long)(a5);
137
138 #define __HYPERCALL_CLOBBER5 "memory"
139 #define __HYPERCALL_CLOBBER4 __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
140 #define __HYPERCALL_CLOBBER3 __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
141 #define __HYPERCALL_CLOBBER2 __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
142 #define __HYPERCALL_CLOBBER1 __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
143 #define __HYPERCALL_CLOBBER0 __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
144
145 #define _hypercall0(type, name) \
146 ({ \
147 __HYPERCALL_DECLS; \
148 __HYPERCALL_0ARG(); \
149 asm volatile (__HYPERCALL \
150 : __HYPERCALL_0PARAM \
151 : __HYPERCALL_ENTRY(name) \
152 : __HYPERCALL_CLOBBER0); \
153 (type)__res; \
154 })
155
156 #define _hypercall1(type, name, a1) \
157 ({ \
158 __HYPERCALL_DECLS; \
159 __HYPERCALL_1ARG(a1); \
160 asm volatile (__HYPERCALL \
161 : __HYPERCALL_1PARAM \
162 : __HYPERCALL_ENTRY(name) \
163 : __HYPERCALL_CLOBBER1); \
164 (type)__res; \
165 })
166
167 #define _hypercall2(type, name, a1, a2) \
168 ({ \
169 __HYPERCALL_DECLS; \
170 __HYPERCALL_2ARG(a1, a2); \
171 asm volatile (__HYPERCALL \
172 : __HYPERCALL_2PARAM \
173 : __HYPERCALL_ENTRY(name) \
174 : __HYPERCALL_CLOBBER2); \
175 (type)__res; \
176 })
177
178 #define _hypercall3(type, name, a1, a2, a3) \
179 ({ \
180 __HYPERCALL_DECLS; \
181 __HYPERCALL_3ARG(a1, a2, a3); \
182 asm volatile (__HYPERCALL \
183 : __HYPERCALL_3PARAM \
184 : __HYPERCALL_ENTRY(name) \
185 : __HYPERCALL_CLOBBER3); \
186 (type)__res; \
187 })
188
189 #define _hypercall4(type, name, a1, a2, a3, a4) \
190 ({ \
191 __HYPERCALL_DECLS; \
192 __HYPERCALL_4ARG(a1, a2, a3, a4); \
193 asm volatile (__HYPERCALL \
194 : __HYPERCALL_4PARAM \
195 : __HYPERCALL_ENTRY(name) \
196 : __HYPERCALL_CLOBBER4); \
197 (type)__res; \
198 })
199
200 static inline long
xen_single_call(unsigned int call,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4,unsigned long a5)201 xen_single_call(unsigned int call,
202 unsigned long a1, unsigned long a2,
203 unsigned long a3, unsigned long a4,
204 unsigned long a5)
205 {
206 __HYPERCALL_DECLS;
207 __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
208
209 if (call >= PAGE_SIZE / sizeof(hypercall_page[0]))
210 return -EINVAL;
211
212 asm volatile(CALL_NOSPEC
213 : __HYPERCALL_5PARAM
214 : [thunk_target] "a" (&hypercall_page[call])
215 : __HYPERCALL_CLOBBER5);
216
217 return (long)__res;
218 }
219
__xen_stac(void)220 static __always_inline void __xen_stac(void)
221 {
222 /*
223 * Suppress objtool seeing the STAC/CLAC and getting confused about it
224 * calling random code with AC=1.
225 */
226 asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
227 ASM_STAC ::: "memory", "flags");
228 }
229
__xen_clac(void)230 static __always_inline void __xen_clac(void)
231 {
232 asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
233 ASM_CLAC ::: "memory", "flags");
234 }
235
236 static inline long
privcmd_call(unsigned int call,unsigned long a1,unsigned long a2,unsigned long a3,unsigned long a4,unsigned long a5)237 privcmd_call(unsigned int call,
238 unsigned long a1, unsigned long a2,
239 unsigned long a3, unsigned long a4,
240 unsigned long a5)
241 {
242 long res;
243
244 __xen_stac();
245 res = xen_single_call(call, a1, a2, a3, a4, a5);
246 __xen_clac();
247
248 return res;
249 }
250
251 static inline int
HYPERVISOR_set_trap_table(struct trap_info * table)252 HYPERVISOR_set_trap_table(struct trap_info *table)
253 {
254 return _hypercall1(int, set_trap_table, table);
255 }
256
257 static inline int
HYPERVISOR_mmu_update(struct mmu_update * req,int count,int * success_count,domid_t domid)258 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
259 int *success_count, domid_t domid)
260 {
261 return _hypercall4(int, mmu_update, req, count, success_count, domid);
262 }
263
264 static inline int
HYPERVISOR_mmuext_op(struct mmuext_op * op,int count,int * success_count,domid_t domid)265 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
266 int *success_count, domid_t domid)
267 {
268 return _hypercall4(int, mmuext_op, op, count, success_count, domid);
269 }
270
271 static inline int
HYPERVISOR_set_gdt(unsigned long * frame_list,int entries)272 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
273 {
274 return _hypercall2(int, set_gdt, frame_list, entries);
275 }
276
277 static inline int
HYPERVISOR_callback_op(int cmd,void * arg)278 HYPERVISOR_callback_op(int cmd, void *arg)
279 {
280 return _hypercall2(int, callback_op, cmd, arg);
281 }
282
283 static inline int
HYPERVISOR_sched_op(int cmd,void * arg)284 HYPERVISOR_sched_op(int cmd, void *arg)
285 {
286 return _hypercall2(int, sched_op, cmd, arg);
287 }
288
289 static inline long
HYPERVISOR_set_timer_op(u64 timeout)290 HYPERVISOR_set_timer_op(u64 timeout)
291 {
292 unsigned long timeout_hi = (unsigned long)(timeout>>32);
293 unsigned long timeout_lo = (unsigned long)timeout;
294 return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
295 }
296
297 static inline int
HYPERVISOR_mca(struct xen_mc * mc_op)298 HYPERVISOR_mca(struct xen_mc *mc_op)
299 {
300 mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
301 return _hypercall1(int, mca, mc_op);
302 }
303
304 static inline int
HYPERVISOR_platform_op(struct xen_platform_op * op)305 HYPERVISOR_platform_op(struct xen_platform_op *op)
306 {
307 op->interface_version = XENPF_INTERFACE_VERSION;
308 return _hypercall1(int, platform_op, op);
309 }
310
311 static inline int
HYPERVISOR_set_debugreg(int reg,unsigned long value)312 HYPERVISOR_set_debugreg(int reg, unsigned long value)
313 {
314 return _hypercall2(int, set_debugreg, reg, value);
315 }
316
317 static inline unsigned long
HYPERVISOR_get_debugreg(int reg)318 HYPERVISOR_get_debugreg(int reg)
319 {
320 return _hypercall1(unsigned long, get_debugreg, reg);
321 }
322
323 static inline int
HYPERVISOR_update_descriptor(u64 ma,u64 desc)324 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
325 {
326 if (sizeof(u64) == sizeof(long))
327 return _hypercall2(int, update_descriptor, ma, desc);
328 return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
329 }
330
331 static inline long
HYPERVISOR_memory_op(unsigned int cmd,void * arg)332 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
333 {
334 return _hypercall2(long, memory_op, cmd, arg);
335 }
336
337 static inline int
HYPERVISOR_multicall(void * call_list,uint32_t nr_calls)338 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
339 {
340 return _hypercall2(int, multicall, call_list, nr_calls);
341 }
342
343 static inline int
HYPERVISOR_update_va_mapping(unsigned long va,pte_t new_val,unsigned long flags)344 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
345 unsigned long flags)
346 {
347 if (sizeof(new_val) == sizeof(long))
348 return _hypercall3(int, update_va_mapping, va,
349 new_val.pte, flags);
350 else
351 return _hypercall4(int, update_va_mapping, va,
352 new_val.pte, new_val.pte >> 32, flags);
353 }
354
355 static inline int
HYPERVISOR_event_channel_op(int cmd,void * arg)356 HYPERVISOR_event_channel_op(int cmd, void *arg)
357 {
358 return _hypercall2(int, event_channel_op, cmd, arg);
359 }
360
361 static inline int
HYPERVISOR_xen_version(int cmd,void * arg)362 HYPERVISOR_xen_version(int cmd, void *arg)
363 {
364 return _hypercall2(int, xen_version, cmd, arg);
365 }
366
367 static inline int
HYPERVISOR_console_io(int cmd,int count,char * str)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
HYPERVISOR_physdev_op(int cmd,void * arg)374 HYPERVISOR_physdev_op(int cmd, void *arg)
375 {
376 return _hypercall2(int, physdev_op, cmd, arg);
377 }
378
379 static inline int
HYPERVISOR_grant_table_op(unsigned int cmd,void * uop,unsigned int count)380 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
381 {
382 return _hypercall3(int, grant_table_op, cmd, uop, count);
383 }
384
385 static inline int
HYPERVISOR_vm_assist(unsigned int cmd,unsigned int type)386 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
387 {
388 return _hypercall2(int, vm_assist, cmd, type);
389 }
390
391 static inline int
HYPERVISOR_vcpu_op(int cmd,int vcpuid,void * extra_args)392 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
393 {
394 return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
395 }
396
397 #ifdef CONFIG_X86_64
398 static inline int
HYPERVISOR_set_segment_base(int reg,unsigned long value)399 HYPERVISOR_set_segment_base(int reg, unsigned long value)
400 {
401 return _hypercall2(int, set_segment_base, reg, value);
402 }
403 #endif
404
405 static inline int
HYPERVISOR_suspend(unsigned long start_info_mfn)406 HYPERVISOR_suspend(unsigned long start_info_mfn)
407 {
408 struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
409
410 /*
411 * For a PV guest the tools require that the start_info mfn be
412 * present in rdx/edx when the hypercall is made. Per the
413 * hypercall calling convention this is the third hypercall
414 * argument, which is start_info_mfn here.
415 */
416 return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
417 }
418
419 static inline unsigned long __must_check
HYPERVISOR_hvm_op(int op,void * arg)420 HYPERVISOR_hvm_op(int op, void *arg)
421 {
422 return _hypercall2(unsigned long, hvm_op, op, arg);
423 }
424
425 static inline int
HYPERVISOR_tmem_op(struct tmem_op * op)426 HYPERVISOR_tmem_op(
427 struct tmem_op *op)
428 {
429 return _hypercall1(int, tmem_op, op);
430 }
431
432 static inline int
HYPERVISOR_xenpmu_op(unsigned int op,void * arg)433 HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
434 {
435 return _hypercall2(int, xenpmu_op, op, arg);
436 }
437
438 static inline int
HYPERVISOR_dm_op(domid_t dom,unsigned int nr_bufs,struct xen_dm_op_buf * bufs)439 HYPERVISOR_dm_op(
440 domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
441 {
442 int ret;
443 __xen_stac();
444 ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
445 __xen_clac();
446 return ret;
447 }
448
449 static inline void
MULTI_fpu_taskswitch(struct multicall_entry * mcl,int set)450 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
451 {
452 mcl->op = __HYPERVISOR_fpu_taskswitch;
453 mcl->args[0] = set;
454
455 trace_xen_mc_entry(mcl, 1);
456 }
457
458 static inline void
MULTI_update_va_mapping(struct multicall_entry * mcl,unsigned long va,pte_t new_val,unsigned long flags)459 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
460 pte_t new_val, unsigned long flags)
461 {
462 mcl->op = __HYPERVISOR_update_va_mapping;
463 mcl->args[0] = va;
464 if (sizeof(new_val) == sizeof(long)) {
465 mcl->args[1] = new_val.pte;
466 mcl->args[2] = flags;
467 } else {
468 mcl->args[1] = new_val.pte;
469 mcl->args[2] = new_val.pte >> 32;
470 mcl->args[3] = flags;
471 }
472
473 trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
474 }
475
476 static inline void
MULTI_update_descriptor(struct multicall_entry * mcl,u64 maddr,struct desc_struct desc)477 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
478 struct desc_struct desc)
479 {
480 mcl->op = __HYPERVISOR_update_descriptor;
481 if (sizeof(maddr) == sizeof(long)) {
482 mcl->args[0] = maddr;
483 mcl->args[1] = *(unsigned long *)&desc;
484 } else {
485 u32 *p = (u32 *)&desc;
486
487 mcl->args[0] = maddr;
488 mcl->args[1] = maddr >> 32;
489 mcl->args[2] = *p++;
490 mcl->args[3] = *p;
491 }
492
493 trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
494 }
495
496 static inline void
MULTI_mmu_update(struct multicall_entry * mcl,struct mmu_update * req,int count,int * success_count,domid_t domid)497 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
498 int count, int *success_count, domid_t domid)
499 {
500 mcl->op = __HYPERVISOR_mmu_update;
501 mcl->args[0] = (unsigned long)req;
502 mcl->args[1] = count;
503 mcl->args[2] = (unsigned long)success_count;
504 mcl->args[3] = domid;
505
506 trace_xen_mc_entry(mcl, 4);
507 }
508
509 static inline void
MULTI_mmuext_op(struct multicall_entry * mcl,struct mmuext_op * op,int count,int * success_count,domid_t domid)510 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
511 int *success_count, domid_t domid)
512 {
513 mcl->op = __HYPERVISOR_mmuext_op;
514 mcl->args[0] = (unsigned long)op;
515 mcl->args[1] = count;
516 mcl->args[2] = (unsigned long)success_count;
517 mcl->args[3] = domid;
518
519 trace_xen_mc_entry(mcl, 4);
520 }
521
522 static inline void
MULTI_stack_switch(struct multicall_entry * mcl,unsigned long ss,unsigned long esp)523 MULTI_stack_switch(struct multicall_entry *mcl,
524 unsigned long ss, unsigned long esp)
525 {
526 mcl->op = __HYPERVISOR_stack_switch;
527 mcl->args[0] = ss;
528 mcl->args[1] = esp;
529
530 trace_xen_mc_entry(mcl, 2);
531 }
532
533 #endif /* _ASM_X86_XEN_HYPERCALL_H */
534
