LXR linux/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#include <xen/interface/platform.h>
  51#include <xen/interface/xen-mca.h>
  52
  53/*
  54 * The hypercall asms have to meet several constraints:
  55 * - Work on 32- and 64-bit.
  56 *    The two architectures put their arguments in different sets of
  57 *    registers.
  58 *
  59 * - Work around asm syntax quirks
  60 *    It isn't possible to specify one of the rNN registers in a
  61 *    constraint, so we use explicit register variables to get the
  62 *    args into the right place.
  63 *
  64 * - Mark all registers as potentially clobbered
  65 *    Even unused parameters can be clobbered by the hypervisor, so we
  66 *    need to make sure gcc knows it.
  67 *
  68 * - Avoid compiler bugs.
  69 *    This is the tricky part.  Because x86_32 has such a constrained
  70 *    register set, gcc versions below 4.3 have trouble generating
  71 *    code when all the arg registers and memory are trashed by the
  72 *    asm.  There are syntactically simpler ways of achieving the
  73 *    semantics below, but they cause the compiler to crash.
  74 *
  75 *    The only combination I found which works is:
  76 *     - assign the __argX variables first
  77 *     - list all actually used parameters as "+r" (__argX)
  78 *     - clobber the rest
  79 *
  80 * The result certainly isn't pretty, and it really shows up cpp's
  81 * weakness as as macro language.  Sorry.  (But let's just give thanks
  82 * there aren't more than 5 arguments...)
  83 */
  84
  85extern struct { char _entry[32]; } hypercall_page[];
  86
  87#define __HYPERCALL             "call hypercall_page+%c[offset]"
  88#define __HYPERCALL_ENTRY(x)                                            \
  89        [offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
  90
  91#ifdef CONFIG_X86_32
  92#define __HYPERCALL_RETREG      "eax"
  93#define __HYPERCALL_ARG1REG     "ebx"
  94#define __HYPERCALL_ARG2REG     "ecx"
  95#define __HYPERCALL_ARG3REG     "edx"
  96#define __HYPERCALL_ARG4REG     "esi"
  97#define __HYPERCALL_ARG5REG     "edi"
  98#else
  99#define __HYPERCALL_RETREG      "rax"
 100#define __HYPERCALL_ARG1REG     "rdi"
 101#define __HYPERCALL_ARG2REG     "rsi"
 102#define __HYPERCALL_ARG3REG     "rdx"
 103#define __HYPERCALL_ARG4REG     "r10"
 104#define __HYPERCALL_ARG5REG     "r8"
 105#endif
 106
 107#define __HYPERCALL_DECLS                                               \
 108        register unsigned long __res  asm(__HYPERCALL_RETREG);          \
 109        register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
 110        register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
 111        register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
 112        register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
 113        register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
 114
 115#define __HYPERCALL_0PARAM      "=r" (__res)
 116#define __HYPERCALL_1PARAM      __HYPERCALL_0PARAM, "+r" (__arg1)
 117#define __HYPERCALL_2PARAM      __HYPERCALL_1PARAM, "+r" (__arg2)
 118#define __HYPERCALL_3PARAM      __HYPERCALL_2PARAM, "+r" (__arg3)
 119#define __HYPERCALL_4PARAM      __HYPERCALL_3PARAM, "+r" (__arg4)
 120#define __HYPERCALL_5PARAM      __HYPERCALL_4PARAM, "+r" (__arg5)
 121
 122#define __HYPERCALL_0ARG()
 123#define __HYPERCALL_1ARG(a1)                                            \
 124        __HYPERCALL_0ARG()              __arg1 = (unsigned long)(a1);
 125#define __HYPERCALL_2ARG(a1,a2)                                         \
 126        __HYPERCALL_1ARG(a1)            __arg2 = (unsigned long)(a2);
 127#define __HYPERCALL_3ARG(a1,a2,a3)                                      \
 128        __HYPERCALL_2ARG(a1,a2)         __arg3 = (unsigned long)(a3);
 129#define __HYPERCALL_4ARG(a1,a2,a3,a4)                                   \
 130        __HYPERCALL_3ARG(a1,a2,a3)      __arg4 = (unsigned long)(a4);
 131#define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)                                \
 132        __HYPERCALL_4ARG(a1,a2,a3,a4)   __arg5 = (unsigned long)(a5);
 133
 134#define __HYPERCALL_CLOBBER5    "memory"
 135#define __HYPERCALL_CLOBBER4    __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
 136#define __HYPERCALL_CLOBBER3    __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
 137#define __HYPERCALL_CLOBBER2    __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
 138#define __HYPERCALL_CLOBBER1    __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
 139#define __HYPERCALL_CLOBBER0    __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
 140
 141#define _hypercall0(type, name)                                         \
 142({                                                                      \
 143        __HYPERCALL_DECLS;                                              \
 144        __HYPERCALL_0ARG();                                             \
 145        asm volatile (__HYPERCALL                                       \
 146                      : __HYPERCALL_0PARAM                              \
 147                      : __HYPERCALL_ENTRY(name)                         \
 148                      : __HYPERCALL_CLOBBER0);                          \
 149        (type)__res;                                                    \
 150})
 151
 152#define _hypercall1(type, name, a1)                                     \
 153({                                                                      \
 154        __HYPERCALL_DECLS;                                              \
 155        __HYPERCALL_1ARG(a1);                                           \
 156        asm volatile (__HYPERCALL                                       \
 157                      : __HYPERCALL_1PARAM                              \
 158                      : __HYPERCALL_ENTRY(name)                         \
 159                      : __HYPERCALL_CLOBBER1);                          \
 160        (type)__res;                                                    \
 161})
 162
 163#define _hypercall2(type, name, a1, a2)                                 \
 164({                                                                      \
 165        __HYPERCALL_DECLS;                                              \
 166        __HYPERCALL_2ARG(a1, a2);                                       \
 167        asm volatile (__HYPERCALL                                       \
 168                      : __HYPERCALL_2PARAM                              \
 169                      : __HYPERCALL_ENTRY(name)                         \
 170                      : __HYPERCALL_CLOBBER2);                          \
 171        (type)__res;                                                    \
 172})
 173
 174#define _hypercall3(type, name, a1, a2, a3)                             \
 175({                                                                      \
 176        __HYPERCALL_DECLS;                                              \
 177        __HYPERCALL_3ARG(a1, a2, a3);                                   \
 178        asm volatile (__HYPERCALL                                       \
 179                      : __HYPERCALL_3PARAM                              \
 180                      : __HYPERCALL_ENTRY(name)                         \
 181                      : __HYPERCALL_CLOBBER3);                          \
 182        (type)__res;                                                    \
 183})
 184
 185#define _hypercall4(type, name, a1, a2, a3, a4)                         \
 186({                                                                      \
 187        __HYPERCALL_DECLS;                                              \
 188        __HYPERCALL_4ARG(a1, a2, a3, a4);                               \
 189        asm volatile (__HYPERCALL                                       \
 190                      : __HYPERCALL_4PARAM                              \
 191                      : __HYPERCALL_ENTRY(name)                         \
 192                      : __HYPERCALL_CLOBBER4);                          \
 193        (type)__res;                                                    \
 194})
 195
 196#define _hypercall5(type, name, a1, a2, a3, a4, a5)                     \
 197({                                                                      \
 198        __HYPERCALL_DECLS;                                              \
 199        __HYPERCALL_5ARG(a1, a2, a3, a4, a5);                           \
 200        asm volatile (__HYPERCALL                                       \
 201                      : __HYPERCALL_5PARAM                              \
 202                      : __HYPERCALL_ENTRY(name)                         \
 203                      : __HYPERCALL_CLOBBER5);                          \
 204        (type)__res;                                                    \
 205})
 206
 207static inline long
 208privcmd_call(unsigned call,
 209             unsigned long a1, unsigned long a2,
 210             unsigned long a3, unsigned long a4,
 211             unsigned long a5)
 212{
 213        __HYPERCALL_DECLS;
 214        __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
 215
 216        asm volatile("call *%[call]"
 217                     : __HYPERCALL_5PARAM
 218                     : [call] "a" (&hypercall_page[call])
 219                     : __HYPERCALL_CLOBBER5);
 220
 221        return (long)__res;
 222}
 223
 224static inline int
 225HYPERVISOR_set_trap_table(struct trap_info *table)
 226{
 227        return _hypercall1(int, set_trap_table, table);
 228}
 229
 230static inline int
 231HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 232                      int *success_count, domid_t domid)
 233{
 234        return _hypercall4(int, mmu_update, req, count, success_count, domid);
 235}
 236
 237static inline int
 238HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 239                     int *success_count, domid_t domid)
 240{
 241        return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 242}
 243
 244static inline int
 245HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 246{
 247        return _hypercall2(int, set_gdt, frame_list, entries);
 248}
 249
 250static inline int
 251HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
 252{
 253        return _hypercall2(int, stack_switch, ss, esp);
 254}
 255
 256#ifdef CONFIG_X86_32
 257static inline int
 258HYPERVISOR_set_callbacks(unsigned long event_selector,
 259                         unsigned long event_address,
 260                         unsigned long failsafe_selector,
 261                         unsigned long failsafe_address)
 262{
 263        return _hypercall4(int, set_callbacks,
 264                           event_selector, event_address,
 265                           failsafe_selector, failsafe_address);
 266}
 267#else  /* CONFIG_X86_64 */
 268static inline int
 269HYPERVISOR_set_callbacks(unsigned long event_address,
 270                        unsigned long failsafe_address,
 271                        unsigned long syscall_address)
 272{
 273        return _hypercall3(int, set_callbacks,
 274                           event_address, failsafe_address,
 275                           syscall_address);
 276}
 277#endif  /* CONFIG_X86_{32,64} */
 278
 279static inline int
 280HYPERVISOR_callback_op(int cmd, void *arg)
 281{
 282        return _hypercall2(int, callback_op, cmd, arg);
 283}
 284
 285static inline int
 286HYPERVISOR_fpu_taskswitch(int set)
 287{
 288        return _hypercall1(int, fpu_taskswitch, set);
 289}
 290
 291static inline int
 292HYPERVISOR_sched_op(int cmd, void *arg)
 293{
 294        return _hypercall2(int, sched_op, cmd, arg);
 295}
 296
 297static inline long
 298HYPERVISOR_set_timer_op(u64 timeout)
 299{
 300        unsigned long timeout_hi = (unsigned long)(timeout>>32);
 301        unsigned long timeout_lo = (unsigned long)timeout;
 302        return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 303}
 304
 305static inline int
 306HYPERVISOR_mca(struct xen_mc *mc_op)
 307{
 308        mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
 309        return _hypercall1(int, mca, mc_op);
 310}
 311
 312static inline int
 313HYPERVISOR_dom0_op(struct xen_platform_op *platform_op)
 314{
 315        platform_op->interface_version = XENPF_INTERFACE_VERSION;
 316        return _hypercall1(int, dom0_op, platform_op);
 317}
 318
 319static inline int
 320HYPERVISOR_set_debugreg(int reg, unsigned long value)
 321{
 322        return _hypercall2(int, set_debugreg, reg, value);
 323}
 324
 325static inline unsigned long
 326HYPERVISOR_get_debugreg(int reg)
 327{
 328        return _hypercall1(unsigned long, get_debugreg, reg);
 329}
 330
 331static inline int
 332HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 333{
 334        if (sizeof(u64) == sizeof(long))
 335                return _hypercall2(int, update_descriptor, ma, desc);
 336        return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 337}
 338
 339static inline int
 340HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 341{
 342        return _hypercall2(int, memory_op, cmd, arg);
 343}
 344
 345static inline int
 346HYPERVISOR_multicall(void *call_list, int nr_calls)
 347{
 348        return _hypercall2(int, multicall, call_list, nr_calls);
 349}
 350
 351static inline int
 352HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 353                             unsigned long flags)
 354{
 355        if (sizeof(new_val) == sizeof(long))
 356                return _hypercall3(int, update_va_mapping, va,
 357                                   new_val.pte, flags);
 358        else
 359                return _hypercall4(int, update_va_mapping, va,
 360                                   new_val.pte, new_val.pte >> 32, flags);
 361}
 362extern int __must_check xen_event_channel_op_compat(int, void *);
 363
 364static inline int
 365HYPERVISOR_event_channel_op(int cmd, void *arg)
 366{
 367        int rc = _hypercall2(int, event_channel_op, cmd, arg);
 368        if (unlikely(rc == -ENOSYS))
 369                rc = xen_event_channel_op_compat(cmd, arg);
 370        return rc;
 371}
 372
 373static inline int
 374HYPERVISOR_xen_version(int cmd, void *arg)
 375{
 376        return _hypercall2(int, xen_version, cmd, arg);
 377}
 378
 379static inline int
 380HYPERVISOR_console_io(int cmd, int count, char *str)
 381{
 382        return _hypercall3(int, console_io, cmd, count, str);
 383}
 384
 385extern int __must_check xen_physdev_op_compat(int, void *);
 386
 387static inline int
 388HYPERVISOR_physdev_op(int cmd, void *arg)
 389{
 390        int rc = _hypercall2(int, physdev_op, cmd, arg);
 391        if (unlikely(rc == -ENOSYS))
 392                rc = xen_physdev_op_compat(cmd, arg);
 393        return rc;
 394}
 395
 396static inline int
 397HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 398{
 399        return _hypercall3(int, grant_table_op, cmd, uop, count);
 400}
 401
 402static inline int
 403HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
 404                                         unsigned long flags, domid_t domid)
 405{
 406        if (sizeof(new_val) == sizeof(long))
 407                return _hypercall4(int, update_va_mapping_otherdomain, va,
 408                                   new_val.pte, flags, domid);
 409        else
 410                return _hypercall5(int, update_va_mapping_otherdomain, va,
 411                                   new_val.pte, new_val.pte >> 32,
 412                                   flags, domid);
 413}
 414
 415static inline int
 416HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 417{
 418        return _hypercall2(int, vm_assist, cmd, type);
 419}
 420
 421static inline int
 422HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 423{
 424        return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 425}
 426
 427#ifdef CONFIG_X86_64
 428static inline int
 429HYPERVISOR_set_segment_base(int reg, unsigned long value)
 430{
 431        return _hypercall2(int, set_segment_base, reg, value);
 432}
 433#endif
 434
 435static inline int
 436HYPERVISOR_suspend(unsigned long start_info_mfn)
 437{
 438        struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 439
 440        /*
 441         * For a PV guest the tools require that the start_info mfn be
 442         * present in rdx/edx when the hypercall is made. Per the
 443         * hypercall calling convention this is the third hypercall
 444         * argument, which is start_info_mfn here.
 445         */
 446        return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 447}
 448
 449static inline int
 450HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
 451{
 452        return _hypercall2(int, nmi_op, op, arg);
 453}
 454
 455static inline unsigned long __must_check
 456HYPERVISOR_hvm_op(int op, void *arg)
 457{
 458       return _hypercall2(unsigned long, hvm_op, op, arg);
 459}
 460
 461static inline int
 462HYPERVISOR_tmem_op(
 463        struct tmem_op *op)
 464{
 465        return _hypercall1(int, tmem_op, op);
 466}
 467
 468static inline void
 469MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 470{
 471        mcl->op = __HYPERVISOR_fpu_taskswitch;
 472        mcl->args[0] = set;
 473
 474        trace_xen_mc_entry(mcl, 1);
 475}
 476
 477static inline void
 478MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 479                        pte_t new_val, unsigned long flags)
 480{
 481        mcl->op = __HYPERVISOR_update_va_mapping;
 482        mcl->args[0] = va;
 483        if (sizeof(new_val) == sizeof(long)) {
 484                mcl->args[1] = new_val.pte;
 485                mcl->args[2] = flags;
 486        } else {
 487                mcl->args[1] = new_val.pte;
 488                mcl->args[2] = new_val.pte >> 32;
 489                mcl->args[3] = flags;
 490        }
 491
 492        trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
 493}
 494
 495static inline void
 496MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
 497                     void *uop, unsigned int count)
 498{
 499        mcl->op = __HYPERVISOR_grant_table_op;
 500        mcl->args[0] = cmd;
 501        mcl->args[1] = (unsigned long)uop;
 502        mcl->args[2] = count;
 503
 504        trace_xen_mc_entry(mcl, 3);
 505}
 506
 507static inline void
 508MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
 509                                    pte_t new_val, unsigned long flags,
 510                                    domid_t domid)
 511{
 512        mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
 513        mcl->args[0] = va;
 514        if (sizeof(new_val) == sizeof(long)) {
 515                mcl->args[1] = new_val.pte;
 516                mcl->args[2] = flags;
 517                mcl->args[3] = domid;
 518        } else {
 519                mcl->args[1] = new_val.pte;
 520                mcl->args[2] = new_val.pte >> 32;
 521                mcl->args[3] = flags;
 522                mcl->args[4] = domid;
 523        }
 524
 525        trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 4 : 5);
 526}
 527
 528static inline void
 529MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 530                        struct desc_struct desc)
 531{
 532        mcl->op = __HYPERVISOR_update_descriptor;
 533        if (sizeof(maddr) == sizeof(long)) {
 534                mcl->args[0] = maddr;
 535                mcl->args[1] = *(unsigned long *)&desc;
 536        } else {
 537                mcl->args[0] = maddr;
 538                mcl->args[1] = maddr >> 32;
 539                mcl->args[2] = desc.a;
 540                mcl->args[3] = desc.b;
 541        }
 542
 543        trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
 544}
 545
 546static inline void
 547MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
 548{
 549        mcl->op = __HYPERVISOR_memory_op;
 550        mcl->args[0] = cmd;
 551        mcl->args[1] = (unsigned long)arg;
 552
 553        trace_xen_mc_entry(mcl, 2);
 554}
 555
 556static inline void
 557MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 558                 int count, int *success_count, domid_t domid)
 559{
 560        mcl->op = __HYPERVISOR_mmu_update;
 561        mcl->args[0] = (unsigned long)req;
 562        mcl->args[1] = count;
 563        mcl->args[2] = (unsigned long)success_count;
 564        mcl->args[3] = domid;
 565
 566        trace_xen_mc_entry(mcl, 4);
 567}
 568
 569static inline void
 570MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 571                int *success_count, domid_t domid)
 572{
 573        mcl->op = __HYPERVISOR_mmuext_op;
 574        mcl->args[0] = (unsigned long)op;
 575        mcl->args[1] = count;
 576        mcl->args[2] = (unsigned long)success_count;
 577        mcl->args[3] = domid;
 578
 579        trace_xen_mc_entry(mcl, 4);
 580}
 581
 582static inline void
 583MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
 584{
 585        mcl->op = __HYPERVISOR_set_gdt;
 586        mcl->args[0] = (unsigned long)frames;
 587        mcl->args[1] = entries;
 588
 589        trace_xen_mc_entry(mcl, 2);
 590}
 591
 592static inline void
 593MULTI_stack_switch(struct multicall_entry *mcl,
 594                   unsigned long ss, unsigned long esp)
 595{
 596        mcl->op = __HYPERVISOR_stack_switch;
 597        mcl->args[0] = ss;
 598        mcl->args[1] = esp;
 599
 600        trace_xen_mc_entry(mcl, 2);
 601}
 602
 603#endif /* _ASM_X86_XEN_HYPERCALL_H */
 604