arch/x86/include/asm/xen/hypercall.h

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