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#include <linux/instrumentation.h>
43
44#include <trace/events/xen.h>
45
46#include <asm/alternative.h>
47#include <asm/page.h>
48#include <asm/smap.h>
49#include <asm/nospec-branch.h>
50
51#include <xen/interface/xen.h>
52#include <xen/interface/sched.h>
53#include <xen/interface/physdev.h>
54#include <xen/interface/platform.h>
55#include <xen/interface/xen-mca.h>
56
57struct xen_dm_op_buf;
58
59/*
60 * The hypercall asms have to meet several constraints:
61 * - Work on 32- and 64-bit.
62 * The two architectures put their arguments in different sets of
63 * registers.
64 *
65 * - Work around asm syntax quirks
66 * It isn't possible to specify one of the rNN registers in a
67 * constraint, so we use explicit register variables to get the
68 * args into the right place.
69 *
70 * - Mark all registers as potentially clobbered
71 * Even unused parameters can be clobbered by the hypervisor, so we
72 * need to make sure gcc knows it.
73 *
74 * - Avoid compiler bugs.
75 * This is the tricky part. Because x86_32 has such a constrained
76 * register set, gcc versions below 4.3 have trouble generating
77 * code when all the arg registers and memory are trashed by the
78 * asm. There are syntactically simpler ways of achieving the
79 * semantics below, but they cause the compiler to crash.
80 *
81 * The only combination I found which works is:
82 * - assign the __argX variables first
83 * - list all actually used parameters as "+r" (__argX)
84 * - clobber the rest
85 *
86 * The result certainly isn't pretty, and it really shows up cpp's
87 * weakness as a macro language. Sorry. (But let's just give thanks
88 * there aren't more than 5 arguments...)
89 */
90
91void xen_hypercall_func(void);
92DECLARE_STATIC_CALL(xen_hypercall, xen_hypercall_func);
93
94#ifdef MODULE
95#define __ADDRESSABLE_xen_hypercall
96#else
97#define __ADDRESSABLE_xen_hypercall __ADDRESSABLE_ASM_STR(__SCK__xen_hypercall)
98#endif
99
100#define __HYPERCALL \
101 __ADDRESSABLE_xen_hypercall \
102 "call __SCT__xen_hypercall"
103
104#define __HYPERCALL_ENTRY(x) "a" (x)
105
106#ifdef CONFIG_X86_32
107#define __HYPERCALL_RETREG "eax"
108#define __HYPERCALL_ARG1REG "ebx"
109#define __HYPERCALL_ARG2REG "ecx"
110#define __HYPERCALL_ARG3REG "edx"
111#define __HYPERCALL_ARG4REG "esi"
112#define __HYPERCALL_ARG5REG "edi"
113#else
114#define __HYPERCALL_RETREG "rax"
115#define __HYPERCALL_ARG1REG "rdi"
116#define __HYPERCALL_ARG2REG "rsi"
117#define __HYPERCALL_ARG3REG "rdx"
118#define __HYPERCALL_ARG4REG "r10"
119#define __HYPERCALL_ARG5REG "r8"
120#endif
121
122#define __HYPERCALL_DECLS \
123 register unsigned long __res asm(__HYPERCALL_RETREG); \
124 register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
125 register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
126 register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
127 register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
128 register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
129
130#define __HYPERCALL_0PARAM "=r" (__res), ASM_CALL_CONSTRAINT
131#define __HYPERCALL_1PARAM __HYPERCALL_0PARAM, "+r" (__arg1)
132#define __HYPERCALL_2PARAM __HYPERCALL_1PARAM, "+r" (__arg2)
133#define __HYPERCALL_3PARAM __HYPERCALL_2PARAM, "+r" (__arg3)
134#define __HYPERCALL_4PARAM __HYPERCALL_3PARAM, "+r" (__arg4)
135#define __HYPERCALL_5PARAM __HYPERCALL_4PARAM, "+r" (__arg5)
136
137#define __HYPERCALL_0ARG()
138#define __HYPERCALL_1ARG(a1) \
139 __HYPERCALL_0ARG() __arg1 = (unsigned long)(a1);
140#define __HYPERCALL_2ARG(a1,a2) \
141 __HYPERCALL_1ARG(a1) __arg2 = (unsigned long)(a2);
142#define __HYPERCALL_3ARG(a1,a2,a3) \
143 __HYPERCALL_2ARG(a1,a2) __arg3 = (unsigned long)(a3);
144#define __HYPERCALL_4ARG(a1,a2,a3,a4) \
145 __HYPERCALL_3ARG(a1,a2,a3) __arg4 = (unsigned long)(a4);
146#define __HYPERCALL_5ARG(a1,a2,a3,a4,a5) \
147 __HYPERCALL_4ARG(a1,a2,a3,a4) __arg5 = (unsigned long)(a5);
148
149#define __HYPERCALL_CLOBBER5 "memory"
150#define __HYPERCALL_CLOBBER4 __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
151#define __HYPERCALL_CLOBBER3 __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
152#define __HYPERCALL_CLOBBER2 __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
153#define __HYPERCALL_CLOBBER1 __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
154#define __HYPERCALL_CLOBBER0 __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
155
156#define _hypercall0(type, name) \
157({ \
158 __HYPERCALL_DECLS; \
159 __HYPERCALL_0ARG(); \
160 asm volatile (__HYPERCALL \
161 : __HYPERCALL_0PARAM \
162 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \
163 : __HYPERCALL_CLOBBER0); \
164 (type)__res; \
165})
166
167#define _hypercall1(type, name, a1) \
168({ \
169 __HYPERCALL_DECLS; \
170 __HYPERCALL_1ARG(a1); \
171 asm volatile (__HYPERCALL \
172 : __HYPERCALL_1PARAM \
173 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \
174 : __HYPERCALL_CLOBBER1); \
175 (type)__res; \
176})
177
178#define _hypercall2(type, name, a1, a2) \
179({ \
180 __HYPERCALL_DECLS; \
181 __HYPERCALL_2ARG(a1, a2); \
182 asm volatile (__HYPERCALL \
183 : __HYPERCALL_2PARAM \
184 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \
185 : __HYPERCALL_CLOBBER2); \
186 (type)__res; \
187})
188
189#define _hypercall3(type, name, a1, a2, a3) \
190({ \
191 __HYPERCALL_DECLS; \
192 __HYPERCALL_3ARG(a1, a2, a3); \
193 asm volatile (__HYPERCALL \
194 : __HYPERCALL_3PARAM \
195 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \
196 : __HYPERCALL_CLOBBER3); \
197 (type)__res; \
198})
199
200#define _hypercall4(type, name, a1, a2, a3, a4) \
201({ \
202 __HYPERCALL_DECLS; \
203 __HYPERCALL_4ARG(a1, a2, a3, a4); \
204 asm volatile (__HYPERCALL \
205 : __HYPERCALL_4PARAM \
206 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \
207 : __HYPERCALL_CLOBBER4); \
208 (type)__res; \
209})
210
211static inline long
212xen_single_call(unsigned int call,
213 unsigned long a1, unsigned long a2,
214 unsigned long a3, unsigned long a4,
215 unsigned long a5)
216{
217 __HYPERCALL_DECLS;
218 __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
219
220 asm volatile(__HYPERCALL
221 : __HYPERCALL_5PARAM
222 : __HYPERCALL_ENTRY(call)
223 : __HYPERCALL_CLOBBER5);
224
225 return (long)__res;
226}
227
228static __always_inline void __xen_stac(void)
229{
230 /*
231 * Suppress objtool seeing the STAC/CLAC and getting confused about it
232 * calling random code with AC=1.
233 */
234 asm volatile(ASM_STAC_UNSAFE ::: "memory", "flags");
235}
236
237static __always_inline void __xen_clac(void)
238{
239 asm volatile(ASM_CLAC_UNSAFE ::: "memory", "flags");
240}
241
242static inline long
243privcmd_call(unsigned int call,
244 unsigned long a1, unsigned long a2,
245 unsigned long a3, unsigned long a4,
246 unsigned long a5)
247{
248 long res;
249
250 __xen_stac();
251 res = xen_single_call(call, a1, a2, a3, a4, a5);
252 __xen_clac();
253
254 return res;
255}
256
257#ifdef CONFIG_XEN_PV
258static inline int
259HYPERVISOR_set_trap_table(struct trap_info *table)
260{
261 return _hypercall1(int, set_trap_table, table);
262}
263
264static inline int
265HYPERVISOR_mmu_update(struct mmu_update *req, int count,
266 int *success_count, domid_t domid)
267{
268 return _hypercall4(int, mmu_update, req, count, success_count, domid);
269}
270
271static inline int
272HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
273 int *success_count, domid_t domid)
274{
275 return _hypercall4(int, mmuext_op, op, count, success_count, domid);
276}
277
278static inline int
279HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
280{
281 return _hypercall2(int, set_gdt, frame_list, entries);
282}
283
284static inline int
285HYPERVISOR_callback_op(int cmd, void *arg)
286{
287 return _hypercall2(int, callback_op, cmd, arg);
288}
289
290static __always_inline int
291HYPERVISOR_set_debugreg(int reg, unsigned long value)
292{
293 return _hypercall2(int, set_debugreg, reg, value);
294}
295
296static __always_inline unsigned long
297HYPERVISOR_get_debugreg(int reg)
298{
299 return _hypercall1(unsigned long, get_debugreg, reg);
300}
301
302static inline int
303HYPERVISOR_update_descriptor(u64 ma, u64 desc)
304{
305 return _hypercall2(int, update_descriptor, ma, desc);
306}
307
308static inline int
309HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
310 unsigned long flags)
311{
312 return _hypercall3(int, update_va_mapping, va, new_val.pte, flags);
313}
314
315static inline int
316HYPERVISOR_set_segment_base(int reg, unsigned long value)
317{
318 return _hypercall2(int, set_segment_base, reg, value);
319}
320
321static inline void
322MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
323{
324 mcl->op = __HYPERVISOR_fpu_taskswitch;
325 mcl->args[0] = set;
326
327 trace_xen_mc_entry(mc: mcl, nargs: 1);
328}
329
330static inline void
331MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
332 pte_t new_val, unsigned long flags)
333{
334 mcl->op = __HYPERVISOR_update_va_mapping;
335 mcl->args[0] = va;
336 mcl->args[1] = new_val.pte;
337 mcl->args[2] = flags;
338
339 trace_xen_mc_entry(mc: mcl, nargs: 3);
340}
341
342static inline void
343MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
344 struct desc_struct desc)
345{
346 mcl->op = __HYPERVISOR_update_descriptor;
347 mcl->args[0] = maddr;
348 mcl->args[1] = *(unsigned long *)&desc;
349
350 trace_xen_mc_entry(mc: mcl, nargs: 2);
351}
352
353static inline void
354MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
355 int count, int *success_count, domid_t domid)
356{
357 mcl->op = __HYPERVISOR_mmu_update;
358 mcl->args[0] = (unsigned long)req;
359 mcl->args[1] = count;
360 mcl->args[2] = (unsigned long)success_count;
361 mcl->args[3] = domid;
362
363 trace_xen_mc_entry(mc: mcl, nargs: 4);
364}
365
366static inline void
367MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
368 int *success_count, domid_t domid)
369{
370 mcl->op = __HYPERVISOR_mmuext_op;
371 mcl->args[0] = (unsigned long)op;
372 mcl->args[1] = count;
373 mcl->args[2] = (unsigned long)success_count;
374 mcl->args[3] = domid;
375
376 trace_xen_mc_entry(mc: mcl, nargs: 4);
377}
378
379static inline void
380MULTI_stack_switch(struct multicall_entry *mcl,
381 unsigned long ss, unsigned long esp)
382{
383 mcl->op = __HYPERVISOR_stack_switch;
384 mcl->args[0] = ss;
385 mcl->args[1] = esp;
386
387 trace_xen_mc_entry(mc: mcl, nargs: 2);
388}
389#endif
390
391static __always_inline int
392HYPERVISOR_sched_op(int cmd, void *arg)
393{
394 return _hypercall2(int, sched_op, cmd, arg);
395}
396
397static inline long
398HYPERVISOR_set_timer_op(u64 timeout)
399{
400 unsigned long timeout_hi = (unsigned long)(timeout>>32);
401 unsigned long timeout_lo = (unsigned long)timeout;
402 return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
403}
404
405static inline int
406HYPERVISOR_mca(struct xen_mc *mc_op)
407{
408 mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
409 return _hypercall1(int, mca, mc_op);
410}
411
412static inline int
413HYPERVISOR_platform_op(struct xen_platform_op *op)
414{
415 op->interface_version = XENPF_INTERFACE_VERSION;
416 return _hypercall1(int, platform_op, op);
417}
418
419static inline long
420HYPERVISOR_memory_op(unsigned int cmd, void *arg)
421{
422 return _hypercall2(long, memory_op, cmd, arg);
423}
424
425static inline int
426HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
427{
428 return _hypercall2(int, multicall, call_list, nr_calls);
429}
430
431static inline int
432HYPERVISOR_event_channel_op(int cmd, void *arg)
433{
434 return _hypercall2(int, event_channel_op, cmd, arg);
435}
436
437static __always_inline int
438HYPERVISOR_xen_version(int cmd, void *arg)
439{
440 return _hypercall2(int, xen_version, cmd, arg);
441}
442
443static inline int
444HYPERVISOR_console_io(int cmd, int count, char *str)
445{
446 return _hypercall3(int, console_io, cmd, count, str);
447}
448
449static inline int
450HYPERVISOR_physdev_op(int cmd, void *arg)
451{
452 return _hypercall2(int, physdev_op, cmd, arg);
453}
454
455static inline int
456HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
457{
458 return _hypercall3(int, grant_table_op, cmd, uop, count);
459}
460
461static inline int
462HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
463{
464 return _hypercall2(int, vm_assist, cmd, type);
465}
466
467static inline int
468HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
469{
470 return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
471}
472
473static inline int
474HYPERVISOR_suspend(unsigned long start_info_mfn)
475{
476 struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
477
478 /*
479 * For a PV guest the tools require that the start_info mfn be
480 * present in rdx/edx when the hypercall is made. Per the
481 * hypercall calling convention this is the third hypercall
482 * argument, which is start_info_mfn here.
483 */
484 return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
485}
486
487static inline unsigned long __must_check
488HYPERVISOR_hvm_op(int op, void *arg)
489{
490 return _hypercall2(unsigned long, hvm_op, op, arg);
491}
492
493static inline int
494HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
495{
496 return _hypercall2(int, xenpmu_op, op, arg);
497}
498
499static inline int
500HYPERVISOR_dm_op(
501 domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
502{
503 int ret;
504 __xen_stac();
505 ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
506 __xen_clac();
507 return ret;
508}
509
510#endif /* _ASM_X86_XEN_HYPERCALL_H */
511

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