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#include <linux/pgtable.h>
42
43#include <trace/events/xen.h>
44
45#include <asm/page.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
55struct 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 a macro language. Sorry. (But let's just give thanks
86 * there aren't more than 5 arguments...)
87 */
88
89extern 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
200static inline long
201xen_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
220static __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
230static __always_inline void __xen_clac(void)
231{
232 asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
233 ASM_CLAC ::: "memory", "flags");
234}
235
236static inline long
237privcmd_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#ifdef CONFIG_XEN_PV
252static inline int
253HYPERVISOR_set_trap_table(struct trap_info *table)
254{
255 return _hypercall1(int, set_trap_table, table);
256}
257
258static inline int
259HYPERVISOR_mmu_update(struct mmu_update *req, int count,
260 int *success_count, domid_t domid)
261{
262 return _hypercall4(int, mmu_update, req, count, success_count, domid);
263}
264
265static inline int
266HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
267 int *success_count, domid_t domid)
268{
269 return _hypercall4(int, mmuext_op, op, count, success_count, domid);
270}
271
272static inline int
273HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
274{
275 return _hypercall2(int, set_gdt, frame_list, entries);
276}
277
278static inline int
279HYPERVISOR_callback_op(int cmd, void *arg)
280{
281 return _hypercall2(int, callback_op, cmd, arg);
282}
283
284static __always_inline int
285HYPERVISOR_set_debugreg(int reg, unsigned long value)
286{
287 return _hypercall2(int, set_debugreg, reg, value);
288}
289
290static __always_inline unsigned long
291HYPERVISOR_get_debugreg(int reg)
292{
293 return _hypercall1(unsigned long, get_debugreg, reg);
294}
295
296static inline int
297HYPERVISOR_update_descriptor(u64 ma, u64 desc)
298{
299 return _hypercall2(int, update_descriptor, ma, desc);
300}
301
302static inline int
303HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
304 unsigned long flags)
305{
306 return _hypercall3(int, update_va_mapping, va, new_val.pte, flags);
307}
308
309static inline int
310HYPERVISOR_set_segment_base(int reg, unsigned long value)
311{
312 return _hypercall2(int, set_segment_base, reg, value);
313}
314
315static inline void
316MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
317{
318 mcl->op = __HYPERVISOR_fpu_taskswitch;
319 mcl->args[0] = set;
320
321 trace_xen_mc_entry(mc: mcl, nargs: 1);
322}
323
324static inline void
325MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
326 pte_t new_val, unsigned long flags)
327{
328 mcl->op = __HYPERVISOR_update_va_mapping;
329 mcl->args[0] = va;
330 mcl->args[1] = new_val.pte;
331 mcl->args[2] = flags;
332
333 trace_xen_mc_entry(mc: mcl, nargs: 3);
334}
335
336static inline void
337MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
338 struct desc_struct desc)
339{
340 mcl->op = __HYPERVISOR_update_descriptor;
341 mcl->args[0] = maddr;
342 mcl->args[1] = *(unsigned long *)&desc;
343
344 trace_xen_mc_entry(mc: mcl, nargs: 2);
345}
346
347static inline void
348MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
349 int count, int *success_count, domid_t domid)
350{
351 mcl->op = __HYPERVISOR_mmu_update;
352 mcl->args[0] = (unsigned long)req;
353 mcl->args[1] = count;
354 mcl->args[2] = (unsigned long)success_count;
355 mcl->args[3] = domid;
356
357 trace_xen_mc_entry(mc: mcl, nargs: 4);
358}
359
360static inline void
361MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
362 int *success_count, domid_t domid)
363{
364 mcl->op = __HYPERVISOR_mmuext_op;
365 mcl->args[0] = (unsigned long)op;
366 mcl->args[1] = count;
367 mcl->args[2] = (unsigned long)success_count;
368 mcl->args[3] = domid;
369
370 trace_xen_mc_entry(mc: mcl, nargs: 4);
371}
372
373static inline void
374MULTI_stack_switch(struct multicall_entry *mcl,
375 unsigned long ss, unsigned long esp)
376{
377 mcl->op = __HYPERVISOR_stack_switch;
378 mcl->args[0] = ss;
379 mcl->args[1] = esp;
380
381 trace_xen_mc_entry(mc: mcl, nargs: 2);
382}
383#endif
384
385static __always_inline int
386HYPERVISOR_sched_op(int cmd, void *arg)
387{
388 return _hypercall2(int, sched_op, cmd, arg);
389}
390
391static inline long
392HYPERVISOR_set_timer_op(u64 timeout)
393{
394 unsigned long timeout_hi = (unsigned long)(timeout>>32);
395 unsigned long timeout_lo = (unsigned long)timeout;
396 return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
397}
398
399static inline int
400HYPERVISOR_mca(struct xen_mc *mc_op)
401{
402 mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
403 return _hypercall1(int, mca, mc_op);
404}
405
406static inline int
407HYPERVISOR_platform_op(struct xen_platform_op *op)
408{
409 op->interface_version = XENPF_INTERFACE_VERSION;
410 return _hypercall1(int, platform_op, op);
411}
412
413static inline long
414HYPERVISOR_memory_op(unsigned int cmd, void *arg)
415{
416 return _hypercall2(long, memory_op, cmd, arg);
417}
418
419static inline int
420HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
421{
422 return _hypercall2(int, multicall, call_list, nr_calls);
423}
424
425static inline int
426HYPERVISOR_event_channel_op(int cmd, void *arg)
427{
428 return _hypercall2(int, event_channel_op, cmd, arg);
429}
430
431static __always_inline int
432HYPERVISOR_xen_version(int cmd, void *arg)
433{
434 return _hypercall2(int, xen_version, cmd, arg);
435}
436
437static inline int
438HYPERVISOR_console_io(int cmd, int count, char *str)
439{
440 return _hypercall3(int, console_io, cmd, count, str);
441}
442
443static inline int
444HYPERVISOR_physdev_op(int cmd, void *arg)
445{
446 return _hypercall2(int, physdev_op, cmd, arg);
447}
448
449static inline int
450HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
451{
452 return _hypercall3(int, grant_table_op, cmd, uop, count);
453}
454
455static inline int
456HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
457{
458 return _hypercall2(int, vm_assist, cmd, type);
459}
460
461static inline int
462HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
463{
464 return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
465}
466
467static inline int
468HYPERVISOR_suspend(unsigned long start_info_mfn)
469{
470 struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
471
472 /*
473 * For a PV guest the tools require that the start_info mfn be
474 * present in rdx/edx when the hypercall is made. Per the
475 * hypercall calling convention this is the third hypercall
476 * argument, which is start_info_mfn here.
477 */
478 return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
479}
480
481static inline unsigned long __must_check
482HYPERVISOR_hvm_op(int op, void *arg)
483{
484 return _hypercall2(unsigned long, hvm_op, op, arg);
485}
486
487static inline int
488HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
489{
490 return _hypercall2(int, xenpmu_op, op, arg);
491}
492
493static inline int
494HYPERVISOR_dm_op(
495 domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
496{
497 int ret;
498 __xen_stac();
499 ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
500 __xen_clac();
501 return ret;
502}
503
504#endif /* _ASM_X86_XEN_HYPERCALL_H */
505

source code of linux/arch/x86/include/asm/xen/hypercall.h