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 #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
  55 struct 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 as macro language.  Sorry.  (But let's just give thanks
  86  * there aren't more than 5 arguments...)
  87  */
  88
  89 extern 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
 200 static inline long
 201 xen_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         asm volatile(CALL_NOSPEC
 210                      : __HYPERCALL_5PARAM
 211                      : [thunk_target] "a" (&hypercall_page[call])
 212                      : __HYPERCALL_CLOBBER5);
 213
 214         return (long)__res;
 215 }
 216
 217 static inline long
 218 privcmd_call(unsigned int call,
 219              unsigned long a1, unsigned long a2,
 220              unsigned long a3, unsigned long a4,
 221              unsigned long a5)
 222 {
 223         long res;
 224
 225         stac();
 226         res = xen_single_call(call, a1, a2, a3, a4, a5);
 227         clac();
 228
 229         return res;
 230 }
 231
 232 static inline int
 233 HYPERVISOR_set_trap_table(struct trap_info *table)
 234 {
 235         return _hypercall1(int, set_trap_table, table);
 236 }
 237
 238 static inline int
 239 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 240                       int *success_count, domid_t domid)
 241 {
 242         return _hypercall4(int, mmu_update, req, count, success_count, domid);
 243 }
 244
 245 static inline int
 246 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 247                      int *success_count, domid_t domid)
 248 {
 249         return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 250 }
 251
 252 static inline int
 253 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 254 {
 255         return _hypercall2(int, set_gdt, frame_list, entries);
 256 }
 257
 258 static inline int
 259 HYPERVISOR_callback_op(int cmd, void *arg)
 260 {
 261         return _hypercall2(int, callback_op, cmd, arg);
 262 }
 263
 264 static inline int
 265 HYPERVISOR_sched_op(int cmd, void *arg)
 266 {
 267         return _hypercall2(int, sched_op, cmd, arg);
 268 }
 269
 270 static inline long
 271 HYPERVISOR_set_timer_op(u64 timeout)
 272 {
 273         unsigned long timeout_hi = (unsigned long)(timeout>>32);
 274         unsigned long timeout_lo = (unsigned long)timeout;
 275         return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 276 }
 277
 278 static inline int
 279 HYPERVISOR_mca(struct xen_mc *mc_op)
 280 {
 281         mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
 282         return _hypercall1(int, mca, mc_op);
 283 }
 284
 285 static inline int
 286 HYPERVISOR_platform_op(struct xen_platform_op *op)
 287 {
 288         op->interface_version = XENPF_INTERFACE_VERSION;
 289         return _hypercall1(int, platform_op, op);
 290 }
 291
 292 static inline int
 293 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 294 {
 295         return _hypercall2(int, set_debugreg, reg, value);
 296 }
 297
 298 static inline unsigned long
 299 HYPERVISOR_get_debugreg(int reg)
 300 {
 301         return _hypercall1(unsigned long, get_debugreg, reg);
 302 }
 303
 304 static inline int
 305 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 306 {
 307         if (sizeof(u64) == sizeof(long))
 308                 return _hypercall2(int, update_descriptor, ma, desc);
 309         return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 310 }
 311
 312 static inline long
 313 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 314 {
 315         return _hypercall2(long, memory_op, cmd, arg);
 316 }
 317
 318 static inline int
 319 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
 320 {
 321         return _hypercall2(int, multicall, call_list, nr_calls);
 322 }
 323
 324 static inline int
 325 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 326                              unsigned long flags)
 327 {
 328         if (sizeof(new_val) == sizeof(long))
 329                 return _hypercall3(int, update_va_mapping, va,
 330                                    new_val.pte, flags);
 331         else
 332                 return _hypercall4(int, update_va_mapping, va,
 333                                    new_val.pte, new_val.pte >> 32, flags);
 334 }
 335 extern int __must_check xen_event_channel_op_compat(int, void *);
 336
 337 static inline int
 338 HYPERVISOR_event_channel_op(int cmd, void *arg)
 339 {
 340         int rc = _hypercall2(int, event_channel_op, cmd, arg);
 341         if (unlikely(rc == -ENOSYS))
 342                 rc = xen_event_channel_op_compat(cmd, arg);
 343         return rc;
 344 }
 345
 346 static inline int
 347 HYPERVISOR_xen_version(int cmd, void *arg)
 348 {
 349         return _hypercall2(int, xen_version, cmd, arg);
 350 }
 351
 352 static inline int
 353 HYPERVISOR_console_io(int cmd, int count, char *str)
 354 {
 355         return _hypercall3(int, console_io, cmd, count, str);
 356 }
 357
 358 extern int __must_check xen_physdev_op_compat(int, void *);
 359
 360 static inline int
 361 HYPERVISOR_physdev_op(int cmd, void *arg)
 362 {
 363         int rc = _hypercall2(int, physdev_op, cmd, arg);
 364         if (unlikely(rc == -ENOSYS))
 365                 rc = xen_physdev_op_compat(cmd, arg);
 366         return rc;
 367 }
 368
 369 static inline int
 370 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 371 {
 372         return _hypercall3(int, grant_table_op, cmd, uop, count);
 373 }
 374
 375 static inline int
 376 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 377 {
 378         return _hypercall2(int, vm_assist, cmd, type);
 379 }
 380
 381 static inline int
 382 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 383 {
 384         return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 385 }
 386
 387 #ifdef CONFIG_X86_64
 388 static inline int
 389 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 390 {
 391         return _hypercall2(int, set_segment_base, reg, value);
 392 }
 393 #endif
 394
 395 static inline int
 396 HYPERVISOR_suspend(unsigned long start_info_mfn)
 397 {
 398         struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 399
 400         /*
 401          * For a PV guest the tools require that the start_info mfn be
 402          * present in rdx/edx when the hypercall is made. Per the
 403          * hypercall calling convention this is the third hypercall
 404          * argument, which is start_info_mfn here.
 405          */
 406         return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 407 }
 408
 409 static inline unsigned long __must_check
 410 HYPERVISOR_hvm_op(int op, void *arg)
 411 {
 412        return _hypercall2(unsigned long, hvm_op, op, arg);
 413 }
 414
 415 static inline int
 416 HYPERVISOR_tmem_op(
 417         struct tmem_op *op)
 418 {
 419         return _hypercall1(int, tmem_op, op);
 420 }
 421
 422 static inline int
 423 HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 424 {
 425         return _hypercall2(int, xenpmu_op, op, arg);
 426 }
 427
 428 static inline int
 429 HYPERVISOR_dm_op(
 430         domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 431 {
 432         int ret;
 433         stac();
 434         ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
 435         clac();
 436         return ret;
 437 }
 438
 439 static inline void
 440 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 441 {
 442         mcl->op = __HYPERVISOR_fpu_taskswitch;
 443         mcl->args[0] = set;
 444
 445         trace_xen_mc_entry(mcl, 1);
 446 }
 447
 448 static inline void
 449 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 450                         pte_t new_val, unsigned long flags)
 451 {
 452         mcl->op = __HYPERVISOR_update_va_mapping;
 453         mcl->args[0] = va;
 454         if (sizeof(new_val) == sizeof(long)) {
 455                 mcl->args[1] = new_val.pte;
 456                 mcl->args[2] = flags;
 457         } else {
 458                 mcl->args[1] = new_val.pte;
 459                 mcl->args[2] = new_val.pte >> 32;
 460                 mcl->args[3] = flags;
 461         }
 462
 463         trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
 464 }
 465
 466 static inline void
 467 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 468                         struct desc_struct desc)
 469 {
 470         mcl->op = __HYPERVISOR_update_descriptor;
 471         if (sizeof(maddr) == sizeof(long)) {
 472                 mcl->args[0] = maddr;
 473                 mcl->args[1] = *(unsigned long *)&desc;
 474         } else {
 475                 u32 *p = (u32 *)&desc;
 476
 477                 mcl->args[0] = maddr;
 478                 mcl->args[1] = maddr >> 32;
 479                 mcl->args[2] = *p++;
 480                 mcl->args[3] = *p;
 481         }
 482
 483         trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
 484 }
 485
 486 static inline void
 487 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 488                  int count, int *success_count, domid_t domid)
 489 {
 490         mcl->op = __HYPERVISOR_mmu_update;
 491         mcl->args[0] = (unsigned long)req;
 492         mcl->args[1] = count;
 493         mcl->args[2] = (unsigned long)success_count;
 494         mcl->args[3] = domid;
 495
 496         trace_xen_mc_entry(mcl, 4);
 497 }
 498
 499 static inline void
 500 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 501                 int *success_count, domid_t domid)
 502 {
 503         mcl->op = __HYPERVISOR_mmuext_op;
 504         mcl->args[0] = (unsigned long)op;
 505         mcl->args[1] = count;
 506         mcl->args[2] = (unsigned long)success_count;
 507         mcl->args[3] = domid;
 508
 509         trace_xen_mc_entry(mcl, 4);
 510 }
 511
 512 static inline void
 513 MULTI_stack_switch(struct multicall_entry *mcl,
 514                    unsigned long ss, unsigned long esp)
 515 {
 516         mcl->op = __HYPERVISOR_stack_switch;
 517         mcl->args[0] = ss;
 518         mcl->args[1] = esp;
 519
 520         trace_xen_mc_entry(mcl, 2);
 521 }
 522
 523 #endif /* _ASM_X86_XEN_HYPERCALL_H */