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 <asm/page.h>
  43 #include <asm/pgtable.h>
  44
  45 #include <xen/interface/xen.h>
  46 #include <xen/interface/sched.h>
  47 #include <xen/interface/physdev.h>
  48
  49 /*
  50  * The hypercall asms have to meet several constraints:
  51  * - Work on 32- and 64-bit.
  52  *    The two architectures put their arguments in different sets of
  53  *    registers.
  54  *
  55  * - Work around asm syntax quirks
  56  *    It isn't possible to specify one of the rNN registers in a
  57  *    constraint, so we use explicit register variables to get the
  58  *    args into the right place.
  59  *
  60  * - Mark all registers as potentially clobbered
  61  *    Even unused parameters can be clobbered by the hypervisor, so we
  62  *    need to make sure gcc knows it.
  63  *
  64  * - Avoid compiler bugs.
  65  *    This is the tricky part.  Because x86_32 has such a constrained
  66  *    register set, gcc versions below 4.3 have trouble generating
  67  *    code when all the arg registers and memory are trashed by the
  68  *    asm.  There are syntactically simpler ways of achieving the
  69  *    semantics below, but they cause the compiler to crash.
  70  *
  71  *    The only combination I found which works is:
  72  *     - assign the __argX variables first
  73  *     - list all actually used parameters as "+r" (__argX)
  74  *     - clobber the rest
  75  *
  76  * The result certainly isn't pretty, and it really shows up cpp's
  77  * weakness as as macro language.  Sorry.  (But let's just give thanks
  78  * there aren't more than 5 arguments...)
  79  */
  80
  81 extern struct { char _entry[32]; } hypercall_page[];
  82
  83 #define __HYPERCALL             "call hypercall_page+%c[offset]"
  84 #define __HYPERCALL_ENTRY(x)                                            \
  85         [offset] "i" (__HYPERVISOR_##x * sizeof(hypercall_page[0]))
  86
  87 #ifdef CONFIG_X86_32
  88 #define __HYPERCALL_RETREG      "eax"
  89 #define __HYPERCALL_ARG1REG     "ebx"
  90 #define __HYPERCALL_ARG2REG     "ecx"
  91 #define __HYPERCALL_ARG3REG     "edx"
  92 #define __HYPERCALL_ARG4REG     "esi"
  93 #define __HYPERCALL_ARG5REG     "edi"
  94 #else
  95 #define __HYPERCALL_RETREG      "rax"
  96 #define __HYPERCALL_ARG1REG     "rdi"
  97 #define __HYPERCALL_ARG2REG     "rsi"
  98 #define __HYPERCALL_ARG3REG     "rdx"
  99 #define __HYPERCALL_ARG4REG     "r10"
 100 #define __HYPERCALL_ARG5REG     "r8"
 101 #endif
 102
 103 #define __HYPERCALL_DECLS                                               \
 104         register unsigned long __res  asm(__HYPERCALL_RETREG);          \
 105         register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
 106         register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
 107         register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
 108         register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
 109         register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
 110
 111 #define __HYPERCALL_0PARAM      "=r" (__res)
 112 #define __HYPERCALL_1PARAM      __HYPERCALL_0PARAM, "+r" (__arg1)
 113 #define __HYPERCALL_2PARAM      __HYPERCALL_1PARAM, "+r" (__arg2)
 114 #define __HYPERCALL_3PARAM      __HYPERCALL_2PARAM, "+r" (__arg3)
 115 #define __HYPERCALL_4PARAM      __HYPERCALL_3PARAM, "+r" (__arg4)
 116 #define __HYPERCALL_5PARAM      __HYPERCALL_4PARAM, "+r" (__arg5)
 117
 118 #define __HYPERCALL_0ARG()
 119 #define __HYPERCALL_1ARG(a1)                                            \
 120         __HYPERCALL_0ARG()              __arg1 = (unsigned long)(a1);
 121 #define __HYPERCALL_2ARG(a1,a2)                                         \
 122         __HYPERCALL_1ARG(a1)            __arg2 = (unsigned long)(a2);
 123 #define __HYPERCALL_3ARG(a1,a2,a3)                                      \
 124         __HYPERCALL_2ARG(a1,a2)         __arg3 = (unsigned long)(a3);
 125 #define __HYPERCALL_4ARG(a1,a2,a3,a4)                                   \
 126         __HYPERCALL_3ARG(a1,a2,a3)      __arg4 = (unsigned long)(a4);
 127 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)                                \
 128         __HYPERCALL_4ARG(a1,a2,a3,a4)   __arg5 = (unsigned long)(a5);
 129
 130 #define __HYPERCALL_CLOBBER5    "memory"
 131 #define __HYPERCALL_CLOBBER4    __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
 132 #define __HYPERCALL_CLOBBER3    __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
 133 #define __HYPERCALL_CLOBBER2    __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
 134 #define __HYPERCALL_CLOBBER1    __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
 135 #define __HYPERCALL_CLOBBER0    __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
 136
 137 #define _hypercall0(type, name)                                         \
 138 ({                                                                      \
 139         __HYPERCALL_DECLS;                                              \
 140         __HYPERCALL_0ARG();                                             \
 141         asm volatile (__HYPERCALL                                       \
 142                       : __HYPERCALL_0PARAM                              \
 143                       : __HYPERCALL_ENTRY(name)                         \
 144                       : __HYPERCALL_CLOBBER0);                          \
 145         (type)__res;                                                    \
 146 })
 147
 148 #define _hypercall1(type, name, a1)                                     \
 149 ({                                                                      \
 150         __HYPERCALL_DECLS;                                              \
 151         __HYPERCALL_1ARG(a1);                                           \
 152         asm volatile (__HYPERCALL                                       \
 153                       : __HYPERCALL_1PARAM                              \
 154                       : __HYPERCALL_ENTRY(name)                         \
 155                       : __HYPERCALL_CLOBBER1);                          \
 156         (type)__res;                                                    \
 157 })
 158
 159 #define _hypercall2(type, name, a1, a2)                                 \
 160 ({                                                                      \
 161         __HYPERCALL_DECLS;                                              \
 162         __HYPERCALL_2ARG(a1, a2);                                       \
 163         asm volatile (__HYPERCALL                                       \
 164                       : __HYPERCALL_2PARAM                              \
 165                       : __HYPERCALL_ENTRY(name)                         \
 166                       : __HYPERCALL_CLOBBER2);                          \
 167         (type)__res;                                                    \
 168 })
 169
 170 #define _hypercall3(type, name, a1, a2, a3)                             \
 171 ({                                                                      \
 172         __HYPERCALL_DECLS;                                              \
 173         __HYPERCALL_3ARG(a1, a2, a3);                                   \
 174         asm volatile (__HYPERCALL                                       \
 175                       : __HYPERCALL_3PARAM                              \
 176                       : __HYPERCALL_ENTRY(name)                         \
 177                       : __HYPERCALL_CLOBBER3);                          \
 178         (type)__res;                                                    \
 179 })
 180
 181 #define _hypercall4(type, name, a1, a2, a3, a4)                         \
 182 ({                                                                      \
 183         __HYPERCALL_DECLS;                                              \
 184         __HYPERCALL_4ARG(a1, a2, a3, a4);                               \
 185         asm volatile (__HYPERCALL                                       \
 186                       : __HYPERCALL_4PARAM                              \
 187                       : __HYPERCALL_ENTRY(name)                         \
 188                       : __HYPERCALL_CLOBBER4);                          \
 189         (type)__res;                                                    \
 190 })
 191
 192 #define _hypercall5(type, name, a1, a2, a3, a4, a5)                     \
 193 ({                                                                      \
 194         __HYPERCALL_DECLS;                                              \
 195         __HYPERCALL_5ARG(a1, a2, a3, a4, a5);                           \
 196         asm volatile (__HYPERCALL                                       \
 197                       : __HYPERCALL_5PARAM                              \
 198                       : __HYPERCALL_ENTRY(name)                         \
 199                       : __HYPERCALL_CLOBBER5);                          \
 200         (type)__res;                                                    \
 201 })
 202
 203 static inline long
 204 privcmd_call(unsigned call,
 205              unsigned long a1, unsigned long a2,
 206              unsigned long a3, unsigned long a4,
 207              unsigned long a5)
 208 {
 209         __HYPERCALL_DECLS;
 210         __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
 211
 212         asm volatile("call *%[call]"
 213                      : __HYPERCALL_5PARAM
 214                      : [call] "a" (&hypercall_page[call])
 215                      : __HYPERCALL_CLOBBER5);
 216
 217         return (long)__res;
 218 }
 219
 220 static inline int
 221 HYPERVISOR_set_trap_table(struct trap_info *table)
 222 {
 223         return _hypercall1(int, set_trap_table, table);
 224 }
 225
 226 static inline int
 227 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 228                       int *success_count, domid_t domid)
 229 {
 230         return _hypercall4(int, mmu_update, req, count, success_count, domid);
 231 }
 232
 233 static inline int
 234 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 235                      int *success_count, domid_t domid)
 236 {
 237         return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 238 }
 239
 240 static inline int
 241 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 242 {
 243         return _hypercall2(int, set_gdt, frame_list, entries);
 244 }
 245
 246 static inline int
 247 HYPERVISOR_stack_switch(unsigned long ss, unsigned long esp)
 248 {
 249         return _hypercall2(int, stack_switch, ss, esp);
 250 }
 251
 252 #ifdef CONFIG_X86_32
 253 static inline int
 254 HYPERVISOR_set_callbacks(unsigned long event_selector,
 255                          unsigned long event_address,
 256                          unsigned long failsafe_selector,
 257                          unsigned long failsafe_address)
 258 {
 259         return _hypercall4(int, set_callbacks,
 260                            event_selector, event_address,
 261                            failsafe_selector, failsafe_address);
 262 }
 263 #else  /* CONFIG_X86_64 */
 264 static inline int
 265 HYPERVISOR_set_callbacks(unsigned long event_address,
 266                         unsigned long failsafe_address,
 267                         unsigned long syscall_address)
 268 {
 269         return _hypercall3(int, set_callbacks,
 270                            event_address, failsafe_address,
 271                            syscall_address);
 272 }
 273 #endif  /* CONFIG_X86_{32,64} */
 274
 275 static inline int
 276 HYPERVISOR_callback_op(int cmd, void *arg)
 277 {
 278         return _hypercall2(int, callback_op, cmd, arg);
 279 }
 280
 281 static inline int
 282 HYPERVISOR_fpu_taskswitch(int set)
 283 {
 284         return _hypercall1(int, fpu_taskswitch, set);
 285 }
 286
 287 static inline int
 288 HYPERVISOR_sched_op(int cmd, void *arg)
 289 {
 290         return _hypercall2(int, sched_op, cmd, arg);
 291 }
 292
 293 static inline long
 294 HYPERVISOR_set_timer_op(u64 timeout)
 295 {
 296         unsigned long timeout_hi = (unsigned long)(timeout>>32);
 297         unsigned long timeout_lo = (unsigned long)timeout;
 298         return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 299 }
 300
 301 static inline int
 302 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 303 {
 304         return _hypercall2(int, set_debugreg, reg, value);
 305 }
 306
 307 static inline unsigned long
 308 HYPERVISOR_get_debugreg(int reg)
 309 {
 310         return _hypercall1(unsigned long, get_debugreg, reg);
 311 }
 312
 313 static inline int
 314 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 315 {
 316         if (sizeof(u64) == sizeof(long))
 317                 return _hypercall2(int, update_descriptor, ma, desc);
 318         return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 319 }
 320
 321 static inline int
 322 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 323 {
 324         return _hypercall2(int, memory_op, cmd, arg);
 325 }
 326
 327 static inline int
 328 HYPERVISOR_multicall(void *call_list, int nr_calls)
 329 {
 330         return _hypercall2(int, multicall, call_list, nr_calls);
 331 }
 332
 333 static inline int
 334 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 335                              unsigned long flags)
 336 {
 337         if (sizeof(new_val) == sizeof(long))
 338                 return _hypercall3(int, update_va_mapping, va,
 339                                    new_val.pte, flags);
 340         else
 341                 return _hypercall4(int, update_va_mapping, va,
 342                                    new_val.pte, new_val.pte >> 32, flags);
 343 }
 344
 345 static inline int
 346 HYPERVISOR_event_channel_op(int cmd, void *arg)
 347 {
 348         int rc = _hypercall2(int, event_channel_op, cmd, arg);
 349         if (unlikely(rc == -ENOSYS)) {
 350                 struct evtchn_op op;
 351                 op.cmd = cmd;
 352                 memcpy(&op.u, arg, sizeof(op.u));
 353                 rc = _hypercall1(int, event_channel_op_compat, &op);
 354                 memcpy(arg, &op.u, sizeof(op.u));
 355         }
 356         return rc;
 357 }
 358
 359 static inline int
 360 HYPERVISOR_xen_version(int cmd, void *arg)
 361 {
 362         return _hypercall2(int, xen_version, cmd, arg);
 363 }
 364
 365 static inline int
 366 HYPERVISOR_console_io(int cmd, int count, char *str)
 367 {
 368         return _hypercall3(int, console_io, cmd, count, str);
 369 }
 370
 371 static inline int
 372 HYPERVISOR_physdev_op(int cmd, void *arg)
 373 {
 374         int rc = _hypercall2(int, physdev_op, cmd, arg);
 375         if (unlikely(rc == -ENOSYS)) {
 376                 struct physdev_op op;
 377                 op.cmd = cmd;
 378                 memcpy(&op.u, arg, sizeof(op.u));
 379                 rc = _hypercall1(int, physdev_op_compat, &op);
 380                 memcpy(arg, &op.u, sizeof(op.u));
 381         }
 382         return rc;
 383 }
 384
 385 static inline int
 386 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 387 {
 388         return _hypercall3(int, grant_table_op, cmd, uop, count);
 389 }
 390
 391 static inline int
 392 HYPERVISOR_update_va_mapping_otherdomain(unsigned long va, pte_t new_val,
 393                                          unsigned long flags, domid_t domid)
 394 {
 395         if (sizeof(new_val) == sizeof(long))
 396                 return _hypercall4(int, update_va_mapping_otherdomain, va,
 397                                    new_val.pte, flags, domid);
 398         else
 399                 return _hypercall5(int, update_va_mapping_otherdomain, va,
 400                                    new_val.pte, new_val.pte >> 32,
 401                                    flags, domid);
 402 }
 403
 404 static inline int
 405 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 406 {
 407         return _hypercall2(int, vm_assist, cmd, type);
 408 }
 409
 410 static inline int
 411 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 412 {
 413         return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 414 }
 415
 416 #ifdef CONFIG_X86_64
 417 static inline int
 418 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 419 {
 420         return _hypercall2(int, set_segment_base, reg, value);
 421 }
 422 #endif
 423
 424 static inline int
 425 HYPERVISOR_suspend(unsigned long start_info_mfn)
 426 {
 427         struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 428
 429         /*
 430          * For a PV guest the tools require that the start_info mfn be
 431          * present in rdx/edx when the hypercall is made. Per the
 432          * hypercall calling convention this is the third hypercall
 433          * argument, which is start_info_mfn here.
 434          */
 435         return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 436 }
 437
 438 static inline int
 439 HYPERVISOR_nmi_op(unsigned long op, unsigned long arg)
 440 {
 441         return _hypercall2(int, nmi_op, op, arg);
 442 }
 443
 444 static inline unsigned long __must_check
 445 HYPERVISOR_hvm_op(int op, void *arg)
 446 {
 447        return _hypercall2(unsigned long, hvm_op, op, arg);
 448 }
 449
 450 static inline int
 451 HYPERVISOR_tmem_op(
 452         struct tmem_op *op)
 453 {
 454         return _hypercall1(int, tmem_op, op);
 455 }
 456
 457 static inline void
 458 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 459 {
 460         mcl->op = __HYPERVISOR_fpu_taskswitch;
 461         mcl->args[0] = set;
 462 }
 463
 464 static inline void
 465 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 466                         pte_t new_val, unsigned long flags)
 467 {
 468         mcl->op = __HYPERVISOR_update_va_mapping;
 469         mcl->args[0] = va;
 470         if (sizeof(new_val) == sizeof(long)) {
 471                 mcl->args[1] = new_val.pte;
 472                 mcl->args[2] = flags;
 473         } else {
 474                 mcl->args[1] = new_val.pte;
 475                 mcl->args[2] = new_val.pte >> 32;
 476                 mcl->args[3] = flags;
 477         }
 478 }
 479
 480 static inline void
 481 MULTI_grant_table_op(struct multicall_entry *mcl, unsigned int cmd,
 482                      void *uop, unsigned int count)
 483 {
 484         mcl->op = __HYPERVISOR_grant_table_op;
 485         mcl->args[0] = cmd;
 486         mcl->args[1] = (unsigned long)uop;
 487         mcl->args[2] = count;
 488 }
 489
 490 static inline void
 491 MULTI_update_va_mapping_otherdomain(struct multicall_entry *mcl, unsigned long va,
 492                                     pte_t new_val, unsigned long flags,
 493                                     domid_t domid)
 494 {
 495         mcl->op = __HYPERVISOR_update_va_mapping_otherdomain;
 496         mcl->args[0] = va;
 497         if (sizeof(new_val) == sizeof(long)) {
 498                 mcl->args[1] = new_val.pte;
 499                 mcl->args[2] = flags;
 500                 mcl->args[3] = domid;
 501         } else {
 502                 mcl->args[1] = new_val.pte;
 503                 mcl->args[2] = new_val.pte >> 32;
 504                 mcl->args[3] = flags;
 505                 mcl->args[4] = domid;
 506         }
 507 }
 508
 509 static inline void
 510 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 511                         struct desc_struct desc)
 512 {
 513         mcl->op = __HYPERVISOR_update_descriptor;
 514         if (sizeof(maddr) == sizeof(long)) {
 515                 mcl->args[0] = maddr;
 516                 mcl->args[1] = *(unsigned long *)&desc;
 517         } else {
 518                 mcl->args[0] = maddr;
 519                 mcl->args[1] = maddr >> 32;
 520                 mcl->args[2] = desc.a;
 521                 mcl->args[3] = desc.b;
 522         }
 523 }
 524
 525 static inline void
 526 MULTI_memory_op(struct multicall_entry *mcl, unsigned int cmd, void *arg)
 527 {
 528         mcl->op = __HYPERVISOR_memory_op;
 529         mcl->args[0] = cmd;
 530         mcl->args[1] = (unsigned long)arg;
 531 }
 532
 533 static inline void
 534 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 535                  int count, int *success_count, domid_t domid)
 536 {
 537         mcl->op = __HYPERVISOR_mmu_update;
 538         mcl->args[0] = (unsigned long)req;
 539         mcl->args[1] = count;
 540         mcl->args[2] = (unsigned long)success_count;
 541         mcl->args[3] = domid;
 542 }
 543
 544 static inline void
 545 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 546                 int *success_count, domid_t domid)
 547 {
 548         mcl->op = __HYPERVISOR_mmuext_op;
 549         mcl->args[0] = (unsigned long)op;
 550         mcl->args[1] = count;
 551         mcl->args[2] = (unsigned long)success_count;
 552         mcl->args[3] = domid;
 553 }
 554
 555 static inline void
 556 MULTI_set_gdt(struct multicall_entry *mcl, unsigned long *frames, int entries)
 557 {
 558         mcl->op = __HYPERVISOR_set_gdt;
 559         mcl->args[0] = (unsigned long)frames;
 560         mcl->args[1] = entries;
 561 }
 562
 563 static inline void
 564 MULTI_stack_switch(struct multicall_entry *mcl,
 565                    unsigned long ss, unsigned long esp)
 566 {
 567         mcl->op = __HYPERVISOR_stack_switch;
 568         mcl->args[0] = ss;
 569         mcl->args[1] = esp;
 570 }
 571
 572 #endif /* _ASM_X86_XEN_HYPERCALL_H */