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         if (call >= PAGE_SIZE / sizeof(hypercall_page[0]))
 210                 return -EINVAL;
 211
 212         asm volatile(CALL_NOSPEC
 213                      : __HYPERCALL_5PARAM
 214                      : [thunk_target] "a" (&hypercall_page[call])
 215                      : __HYPERCALL_CLOBBER5);
 216
 217         return (long)__res;
 218 }
 219
 220 static inline long
 221 privcmd_call(unsigned int call,
 222              unsigned long a1, unsigned long a2,
 223              unsigned long a3, unsigned long a4,
 224              unsigned long a5)
 225 {
 226         long res;
 227
 228         stac();
 229         res = xen_single_call(call, a1, a2, a3, a4, a5);
 230         clac();
 231
 232         return res;
 233 }
 234
 235 static inline int
 236 HYPERVISOR_set_trap_table(struct trap_info *table)
 237 {
 238         return _hypercall1(int, set_trap_table, table);
 239 }
 240
 241 static inline int
 242 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 243                       int *success_count, domid_t domid)
 244 {
 245         return _hypercall4(int, mmu_update, req, count, success_count, domid);
 246 }
 247
 248 static inline int
 249 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 250                      int *success_count, domid_t domid)
 251 {
 252         return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 253 }
 254
 255 static inline int
 256 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 257 {
 258         return _hypercall2(int, set_gdt, frame_list, entries);
 259 }
 260
 261 static inline int
 262 HYPERVISOR_callback_op(int cmd, void *arg)
 263 {
 264         return _hypercall2(int, callback_op, cmd, arg);
 265 }
 266
 267 static inline int
 268 HYPERVISOR_sched_op(int cmd, void *arg)
 269 {
 270         return _hypercall2(int, sched_op, cmd, arg);
 271 }
 272
 273 static inline long
 274 HYPERVISOR_set_timer_op(u64 timeout)
 275 {
 276         unsigned long timeout_hi = (unsigned long)(timeout>>32);
 277         unsigned long timeout_lo = (unsigned long)timeout;
 278         return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 279 }
 280
 281 static inline int
 282 HYPERVISOR_mca(struct xen_mc *mc_op)
 283 {
 284         mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
 285         return _hypercall1(int, mca, mc_op);
 286 }
 287
 288 static inline int
 289 HYPERVISOR_platform_op(struct xen_platform_op *op)
 290 {
 291         op->interface_version = XENPF_INTERFACE_VERSION;
 292         return _hypercall1(int, platform_op, op);
 293 }
 294
 295 static inline int
 296 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 297 {
 298         return _hypercall2(int, set_debugreg, reg, value);
 299 }
 300
 301 static inline unsigned long
 302 HYPERVISOR_get_debugreg(int reg)
 303 {
 304         return _hypercall1(unsigned long, get_debugreg, reg);
 305 }
 306
 307 static inline int
 308 HYPERVISOR_update_descriptor(u64 ma, u64 desc)
 309 {
 310         if (sizeof(u64) == sizeof(long))
 311                 return _hypercall2(int, update_descriptor, ma, desc);
 312         return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32);
 313 }
 314
 315 static inline long
 316 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 317 {
 318         return _hypercall2(long, memory_op, cmd, arg);
 319 }
 320
 321 static inline int
 322 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
 323 {
 324         return _hypercall2(int, multicall, call_list, nr_calls);
 325 }
 326
 327 static inline int
 328 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 329                              unsigned long flags)
 330 {
 331         if (sizeof(new_val) == sizeof(long))
 332                 return _hypercall3(int, update_va_mapping, va,
 333                                    new_val.pte, flags);
 334         else
 335                 return _hypercall4(int, update_va_mapping, va,
 336                                    new_val.pte, new_val.pte >> 32, flags);
 337 }
 338 extern int __must_check xen_event_channel_op_compat(int, void *);
 339
 340 static inline int
 341 HYPERVISOR_event_channel_op(int cmd, void *arg)
 342 {
 343         int rc = _hypercall2(int, event_channel_op, cmd, arg);
 344         if (unlikely(rc == -ENOSYS))
 345                 rc = xen_event_channel_op_compat(cmd, arg);
 346         return rc;
 347 }
 348
 349 static inline int
 350 HYPERVISOR_xen_version(int cmd, void *arg)
 351 {
 352         return _hypercall2(int, xen_version, cmd, arg);
 353 }
 354
 355 static inline int
 356 HYPERVISOR_console_io(int cmd, int count, char *str)
 357 {
 358         return _hypercall3(int, console_io, cmd, count, str);
 359 }
 360
 361 extern int __must_check xen_physdev_op_compat(int, void *);
 362
 363 static inline int
 364 HYPERVISOR_physdev_op(int cmd, void *arg)
 365 {
 366         int rc = _hypercall2(int, physdev_op, cmd, arg);
 367         if (unlikely(rc == -ENOSYS))
 368                 rc = xen_physdev_op_compat(cmd, arg);
 369         return rc;
 370 }
 371
 372 static inline int
 373 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 374 {
 375         return _hypercall3(int, grant_table_op, cmd, uop, count);
 376 }
 377
 378 static inline int
 379 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 380 {
 381         return _hypercall2(int, vm_assist, cmd, type);
 382 }
 383
 384 static inline int
 385 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 386 {
 387         return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 388 }
 389
 390 #ifdef CONFIG_X86_64
 391 static inline int
 392 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 393 {
 394         return _hypercall2(int, set_segment_base, reg, value);
 395 }
 396 #endif
 397
 398 static inline int
 399 HYPERVISOR_suspend(unsigned long start_info_mfn)
 400 {
 401         struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 402
 403         /*
 404          * For a PV guest the tools require that the start_info mfn be
 405          * present in rdx/edx when the hypercall is made. Per the
 406          * hypercall calling convention this is the third hypercall
 407          * argument, which is start_info_mfn here.
 408          */
 409         return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 410 }
 411
 412 static inline unsigned long __must_check
 413 HYPERVISOR_hvm_op(int op, void *arg)
 414 {
 415        return _hypercall2(unsigned long, hvm_op, op, arg);
 416 }
 417
 418 static inline int
 419 HYPERVISOR_tmem_op(
 420         struct tmem_op *op)
 421 {
 422         return _hypercall1(int, tmem_op, op);
 423 }
 424
 425 static inline int
 426 HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 427 {
 428         return _hypercall2(int, xenpmu_op, op, arg);
 429 }
 430
 431 static inline int
 432 HYPERVISOR_dm_op(
 433         domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 434 {
 435         int ret;
 436         stac();
 437         ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
 438         clac();
 439         return ret;
 440 }
 441
 442 static inline void
 443 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 444 {
 445         mcl->op = __HYPERVISOR_fpu_taskswitch;
 446         mcl->args[0] = set;
 447
 448         trace_xen_mc_entry(mcl, 1);
 449 }
 450
 451 static inline void
 452 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 453                         pte_t new_val, unsigned long flags)
 454 {
 455         mcl->op = __HYPERVISOR_update_va_mapping;
 456         mcl->args[0] = va;
 457         if (sizeof(new_val) == sizeof(long)) {
 458                 mcl->args[1] = new_val.pte;
 459                 mcl->args[2] = flags;
 460         } else {
 461                 mcl->args[1] = new_val.pte;
 462                 mcl->args[2] = new_val.pte >> 32;
 463                 mcl->args[3] = flags;
 464         }
 465
 466         trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4);
 467 }
 468
 469 static inline void
 470 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 471                         struct desc_struct desc)
 472 {
 473         mcl->op = __HYPERVISOR_update_descriptor;
 474         if (sizeof(maddr) == sizeof(long)) {
 475                 mcl->args[0] = maddr;
 476                 mcl->args[1] = *(unsigned long *)&desc;
 477         } else {
 478                 u32 *p = (u32 *)&desc;
 479
 480                 mcl->args[0] = maddr;
 481                 mcl->args[1] = maddr >> 32;
 482                 mcl->args[2] = *p++;
 483                 mcl->args[3] = *p;
 484         }
 485
 486         trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4);
 487 }
 488
 489 static inline void
 490 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 491                  int count, int *success_count, domid_t domid)
 492 {
 493         mcl->op = __HYPERVISOR_mmu_update;
 494         mcl->args[0] = (unsigned long)req;
 495         mcl->args[1] = count;
 496         mcl->args[2] = (unsigned long)success_count;
 497         mcl->args[3] = domid;
 498
 499         trace_xen_mc_entry(mcl, 4);
 500 }
 501
 502 static inline void
 503 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 504                 int *success_count, domid_t domid)
 505 {
 506         mcl->op = __HYPERVISOR_mmuext_op;
 507         mcl->args[0] = (unsigned long)op;
 508         mcl->args[1] = count;
 509         mcl->args[2] = (unsigned long)success_count;
 510         mcl->args[3] = domid;
 511
 512         trace_xen_mc_entry(mcl, 4);
 513 }
 514
 515 static inline void
 516 MULTI_stack_switch(struct multicall_entry *mcl,
 517                    unsigned long ss, unsigned long esp)
 518 {
 519         mcl->op = __HYPERVISOR_stack_switch;
 520         mcl->args[0] = ss;
 521         mcl->args[1] = esp;
 522
 523         trace_xen_mc_entry(mcl, 2);
 524 }
 525
 526 #endif /* _ASM_X86_XEN_HYPERCALL_H */