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
251static inline int
252HYPERVISOR_set_trap_table(struct trap_info *table)
253{
254	return _hypercall1(int, set_trap_table, table);
255}
256
257static inline int
258HYPERVISOR_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
264static inline int
265HYPERVISOR_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
271static inline int
272HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
273{
274	return _hypercall2(int, set_gdt, frame_list, entries);
275}
276
277static inline int
278HYPERVISOR_callback_op(int cmd, void *arg)
279{
280	return _hypercall2(int, callback_op, cmd, arg);
281}
282
283static inline int
284HYPERVISOR_sched_op(int cmd, void *arg)
285{
286	return _hypercall2(int, sched_op, cmd, arg);
287}
288
289static inline long
290HYPERVISOR_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
297static inline int
298HYPERVISOR_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
304static inline int
305HYPERVISOR_platform_op(struct xen_platform_op *op)
306{
307	op->interface_version = XENPF_INTERFACE_VERSION;
308	return _hypercall1(int, platform_op, op);
309}
310
311static inline int
312HYPERVISOR_set_debugreg(int reg, unsigned long value)
313{
314	return _hypercall2(int, set_debugreg, reg, value);
315}
316
317static inline unsigned long
318HYPERVISOR_get_debugreg(int reg)
319{
320	return _hypercall1(unsigned long, get_debugreg, reg);
321}
322
323static inline int
324HYPERVISOR_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
331static inline long
332HYPERVISOR_memory_op(unsigned int cmd, void *arg)
333{
334	return _hypercall2(long, memory_op, cmd, arg);
335}
336
337static inline int
338HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
339{
340	return _hypercall2(int, multicall, call_list, nr_calls);
341}
342
343static inline int
344HYPERVISOR_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
355static inline int
356HYPERVISOR_event_channel_op(int cmd, void *arg)
357{
358	return _hypercall2(int, event_channel_op, cmd, arg);
359}
360
361static inline int
362HYPERVISOR_xen_version(int cmd, void *arg)
363{
364	return _hypercall2(int, xen_version, cmd, arg);
365}
366
367static inline int
368HYPERVISOR_console_io(int cmd, int count, char *str)
369{
370	return _hypercall3(int, console_io, cmd, count, str);
371}
372
373static inline int
374HYPERVISOR_physdev_op(int cmd, void *arg)
375{
376	return _hypercall2(int, physdev_op, cmd, arg);
377}
378
379static inline int
380HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
381{
382	return _hypercall3(int, grant_table_op, cmd, uop, count);
383}
384
385static inline int
386HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
387{
388	return _hypercall2(int, vm_assist, cmd, type);
389}
390
391static inline int
392HYPERVISOR_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
398static inline int
399HYPERVISOR_set_segment_base(int reg, unsigned long value)
400{
401	return _hypercall2(int, set_segment_base, reg, value);
402}
403#endif
404
405static inline int
406HYPERVISOR_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
419static inline unsigned long __must_check
420HYPERVISOR_hvm_op(int op, void *arg)
421{
422       return _hypercall2(unsigned long, hvm_op, op, arg);
423}
424
425static inline int
426HYPERVISOR_tmem_op(
427	struct tmem_op *op)
428{
429	return _hypercall1(int, tmem_op, op);
430}
431
432static inline int
433HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
434{
435	return _hypercall2(int, xenpmu_op, op, arg);
436}
437
438static inline int
439HYPERVISOR_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
449static inline void
450MULTI_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
458static inline void
459MULTI_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
476static inline void
477MULTI_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
496static inline void
497MULTI_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
509static inline void
510MULTI_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
522static inline void
523MULTI_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