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 #include <linux/pgtable.h>
  42 #include <linux/instrumentation.h>
  43
  44 #include <trace/events/xen.h>
  45
  46 #include <asm/alternative.h>
  47 #include <asm/page.h>
  48 #include <asm/smap.h>
  49 #include <asm/nospec-branch.h>
  50
  51 #include <xen/interface/xen.h>
  52 #include <xen/interface/sched.h>
  53 #include <xen/interface/physdev.h>
  54 #include <xen/interface/platform.h>
  55 #include <xen/interface/xen-mca.h>
  56
  57 struct xen_dm_op_buf;
  58
  59 /*
  60  * The hypercall asms have to meet several constraints:
  61  * - Work on 32- and 64-bit.
  62  *    The two architectures put their arguments in different sets of
  63  *    registers.
  64  *
  65  * - Work around asm syntax quirks
  66  *    It isn't possible to specify one of the rNN registers in a
  67  *    constraint, so we use explicit register variables to get the
  68  *    args into the right place.
  69  *
  70  * - Mark all registers as potentially clobbered
  71  *    Even unused parameters can be clobbered by the hypervisor, so we
  72  *    need to make sure gcc knows it.
  73  *
  74  * - Avoid compiler bugs.
  75  *    This is the tricky part.  Because x86_32 has such a constrained
  76  *    register set, gcc versions below 4.3 have trouble generating
  77  *    code when all the arg registers and memory are trashed by the
  78  *    asm.  There are syntactically simpler ways of achieving the
  79  *    semantics below, but they cause the compiler to crash.
  80  *
  81  *    The only combination I found which works is:
  82  *     - assign the __argX variables first
  83  *     - list all actually used parameters as "+r" (__argX)
  84  *     - clobber the rest
  85  *
  86  * The result certainly isn't pretty, and it really shows up cpp's
  87  * weakness as a macro language.  Sorry.  (But let's just give thanks
  88  * there aren't more than 5 arguments...)
  89  */
  90
  91 void xen_hypercall_func(void);
  92 DECLARE_STATIC_CALL(xen_hypercall, xen_hypercall_func);
  93
  94 #ifdef MODULE
  95 #define __ADDRESSABLE_xen_hypercall
  96 #else
  97 #define __ADDRESSABLE_xen_hypercall __ADDRESSABLE_ASM_STR(__SCK__xen_hypercall)
  98 #endif
  99
 100 #define __HYPERCALL                                     \
 101         __ADDRESSABLE_xen_hypercall                     \
 102         "call __SCT__xen_hypercall"
 103
 104 #define __HYPERCALL_ENTRY(x)    "a" (x)
 105
 106 #ifdef CONFIG_X86_32
 107 #define __HYPERCALL_RETREG      "eax"
 108 #define __HYPERCALL_ARG1REG     "ebx"
 109 #define __HYPERCALL_ARG2REG     "ecx"
 110 #define __HYPERCALL_ARG3REG     "edx"
 111 #define __HYPERCALL_ARG4REG     "esi"
 112 #define __HYPERCALL_ARG5REG     "edi"
 113 #else
 114 #define __HYPERCALL_RETREG      "rax"
 115 #define __HYPERCALL_ARG1REG     "rdi"
 116 #define __HYPERCALL_ARG2REG     "rsi"
 117 #define __HYPERCALL_ARG3REG     "rdx"
 118 #define __HYPERCALL_ARG4REG     "r10"
 119 #define __HYPERCALL_ARG5REG     "r8"
 120 #endif
 121
 122 #define __HYPERCALL_DECLS                                               \
 123         register unsigned long __res  asm(__HYPERCALL_RETREG);          \
 124         register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \
 125         register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \
 126         register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \
 127         register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \
 128         register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5;
 129
 130 #define __HYPERCALL_0PARAM      "=r" (__res), ASM_CALL_CONSTRAINT
 131 #define __HYPERCALL_1PARAM      __HYPERCALL_0PARAM, "+r" (__arg1)
 132 #define __HYPERCALL_2PARAM      __HYPERCALL_1PARAM, "+r" (__arg2)
 133 #define __HYPERCALL_3PARAM      __HYPERCALL_2PARAM, "+r" (__arg3)
 134 #define __HYPERCALL_4PARAM      __HYPERCALL_3PARAM, "+r" (__arg4)
 135 #define __HYPERCALL_5PARAM      __HYPERCALL_4PARAM, "+r" (__arg5)
 136
 137 #define __HYPERCALL_0ARG()
 138 #define __HYPERCALL_1ARG(a1)                                            \
 139         __HYPERCALL_0ARG()              __arg1 = (unsigned long)(a1);
 140 #define __HYPERCALL_2ARG(a1,a2)                                         \
 141         __HYPERCALL_1ARG(a1)            __arg2 = (unsigned long)(a2);
 142 #define __HYPERCALL_3ARG(a1,a2,a3)                                      \
 143         __HYPERCALL_2ARG(a1,a2)         __arg3 = (unsigned long)(a3);
 144 #define __HYPERCALL_4ARG(a1,a2,a3,a4)                                   \
 145         __HYPERCALL_3ARG(a1,a2,a3)      __arg4 = (unsigned long)(a4);
 146 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5)                                \
 147         __HYPERCALL_4ARG(a1,a2,a3,a4)   __arg5 = (unsigned long)(a5);
 148
 149 #define __HYPERCALL_CLOBBER5    "memory"
 150 #define __HYPERCALL_CLOBBER4    __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG
 151 #define __HYPERCALL_CLOBBER3    __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG
 152 #define __HYPERCALL_CLOBBER2    __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG
 153 #define __HYPERCALL_CLOBBER1    __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG
 154 #define __HYPERCALL_CLOBBER0    __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG
 155
 156 #define _hypercall0(type, name)                                         \
 157 ({                                                                      \
 158         __HYPERCALL_DECLS;                                              \
 159         __HYPERCALL_0ARG();                                             \
 160         asm volatile (__HYPERCALL                                       \
 161                       : __HYPERCALL_0PARAM                              \
 162                       : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name)        \
 163                       : __HYPERCALL_CLOBBER0);                          \
 164         (type)__res;                                                    \
 165 })
 166
 167 #define _hypercall1(type, name, a1)                                     \
 168 ({                                                                      \
 169         __HYPERCALL_DECLS;                                              \
 170         __HYPERCALL_1ARG(a1);                                           \
 171         asm volatile (__HYPERCALL                                       \
 172                       : __HYPERCALL_1PARAM                              \
 173                       : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name)        \
 174                       : __HYPERCALL_CLOBBER1);                          \
 175         (type)__res;                                                    \
 176 })
 177
 178 #define _hypercall2(type, name, a1, a2)                                 \
 179 ({                                                                      \
 180         __HYPERCALL_DECLS;                                              \
 181         __HYPERCALL_2ARG(a1, a2);                                       \
 182         asm volatile (__HYPERCALL                                       \
 183                       : __HYPERCALL_2PARAM                              \
 184                       : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name)        \
 185                       : __HYPERCALL_CLOBBER2);                          \
 186         (type)__res;                                                    \
 187 })
 188
 189 #define _hypercall3(type, name, a1, a2, a3)                             \
 190 ({                                                                      \
 191         __HYPERCALL_DECLS;                                              \
 192         __HYPERCALL_3ARG(a1, a2, a3);                                   \
 193         asm volatile (__HYPERCALL                                       \
 194                       : __HYPERCALL_3PARAM                              \
 195                       : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name)        \
 196                       : __HYPERCALL_CLOBBER3);                          \
 197         (type)__res;                                                    \
 198 })
 199
 200 #define _hypercall4(type, name, a1, a2, a3, a4)                         \
 201 ({                                                                      \
 202         __HYPERCALL_DECLS;                                              \
 203         __HYPERCALL_4ARG(a1, a2, a3, a4);                               \
 204         asm volatile (__HYPERCALL                                       \
 205                       : __HYPERCALL_4PARAM                              \
 206                       : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name)        \
 207                       : __HYPERCALL_CLOBBER4);                          \
 208         (type)__res;                                                    \
 209 })
 210
 211 static inline long
 212 xen_single_call(unsigned int call,
 213                 unsigned long a1, unsigned long a2,
 214                 unsigned long a3, unsigned long a4,
 215                 unsigned long a5)
 216 {
 217         __HYPERCALL_DECLS;
 218         __HYPERCALL_5ARG(a1, a2, a3, a4, a5);
 219
 220         asm volatile(__HYPERCALL
 221                      : __HYPERCALL_5PARAM
 222                      : __HYPERCALL_ENTRY(call)
 223                      : __HYPERCALL_CLOBBER5);
 224
 225         return (long)__res;
 226 }
 227
 228 static __always_inline void __xen_stac(void)
 229 {
 230         /*
 231          * Suppress objtool seeing the STAC/CLAC and getting confused about it
 232          * calling random code with AC=1.
 233          */
 234         asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
 235                      ASM_STAC ::: "memory", "flags");
 236 }
 237
 238 static __always_inline void __xen_clac(void)
 239 {
 240         asm volatile(ANNOTATE_IGNORE_ALTERNATIVE
 241                      ASM_CLAC ::: "memory", "flags");
 242 }
 243
 244 static inline long
 245 privcmd_call(unsigned int call,
 246              unsigned long a1, unsigned long a2,
 247              unsigned long a3, unsigned long a4,
 248              unsigned long a5)
 249 {
 250         long res;
 251
 252         __xen_stac();
 253         res = xen_single_call(call, a1, a2, a3, a4, a5);
 254         __xen_clac();
 255
 256         return res;
 257 }
 258
 259 #ifdef CONFIG_XEN_PV
 260 static inline int
 261 HYPERVISOR_set_trap_table(struct trap_info *table)
 262 {
 263         return _hypercall1(int, set_trap_table, table);
 264 }
 265
 266 static inline int
 267 HYPERVISOR_mmu_update(struct mmu_update *req, int count,
 268                       int *success_count, domid_t domid)
 269 {
 270         return _hypercall4(int, mmu_update, req, count, success_count, domid);
 271 }
 272
 273 static inline int
 274 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count,
 275                      int *success_count, domid_t domid)
 276 {
 277         return _hypercall4(int, mmuext_op, op, count, success_count, domid);
 278 }
 279
 280 static inline int
 281 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries)
 282 {
 283         return _hypercall2(int, set_gdt, frame_list, entries);
 284 }
 285
 286 static inline int
 287 HYPERVISOR_callback_op(int cmd, void *arg)
 288 {
 289         return _hypercall2(int, callback_op, cmd, arg);
 290 }
 291
 292 static __always_inline int
 293 HYPERVISOR_set_debugreg(int reg, unsigned long value)
 294 {
 295         return _hypercall2(int, set_debugreg, reg, value);
 296 }
 297
 298 static __always_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         return _hypercall2(int, update_descriptor, ma, desc);
 308 }
 309
 310 static inline int
 311 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val,
 312                              unsigned long flags)
 313 {
 314         return _hypercall3(int, update_va_mapping, va, new_val.pte, flags);
 315 }
 316
 317 static inline int
 318 HYPERVISOR_set_segment_base(int reg, unsigned long value)
 319 {
 320         return _hypercall2(int, set_segment_base, reg, value);
 321 }
 322
 323 static inline void
 324 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set)
 325 {
 326         mcl->op = __HYPERVISOR_fpu_taskswitch;
 327         mcl->args[0] = set;
 328
 329         trace_xen_mc_entry(mcl, 1);
 330 }
 331
 332 static inline void
 333 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va,
 334                         pte_t new_val, unsigned long flags)
 335 {
 336         mcl->op = __HYPERVISOR_update_va_mapping;
 337         mcl->args[0] = va;
 338         mcl->args[1] = new_val.pte;
 339         mcl->args[2] = flags;
 340
 341         trace_xen_mc_entry(mcl, 3);
 342 }
 343
 344 static inline void
 345 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr,
 346                         struct desc_struct desc)
 347 {
 348         mcl->op = __HYPERVISOR_update_descriptor;
 349         mcl->args[0] = maddr;
 350         mcl->args[1] = *(unsigned long *)&desc;
 351
 352         trace_xen_mc_entry(mcl, 2);
 353 }
 354
 355 static inline void
 356 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req,
 357                  int count, int *success_count, domid_t domid)
 358 {
 359         mcl->op = __HYPERVISOR_mmu_update;
 360         mcl->args[0] = (unsigned long)req;
 361         mcl->args[1] = count;
 362         mcl->args[2] = (unsigned long)success_count;
 363         mcl->args[3] = domid;
 364
 365         trace_xen_mc_entry(mcl, 4);
 366 }
 367
 368 static inline void
 369 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count,
 370                 int *success_count, domid_t domid)
 371 {
 372         mcl->op = __HYPERVISOR_mmuext_op;
 373         mcl->args[0] = (unsigned long)op;
 374         mcl->args[1] = count;
 375         mcl->args[2] = (unsigned long)success_count;
 376         mcl->args[3] = domid;
 377
 378         trace_xen_mc_entry(mcl, 4);
 379 }
 380
 381 static inline void
 382 MULTI_stack_switch(struct multicall_entry *mcl,
 383                    unsigned long ss, unsigned long esp)
 384 {
 385         mcl->op = __HYPERVISOR_stack_switch;
 386         mcl->args[0] = ss;
 387         mcl->args[1] = esp;
 388
 389         trace_xen_mc_entry(mcl, 2);
 390 }
 391 #endif
 392
 393 static __always_inline int
 394 HYPERVISOR_sched_op(int cmd, void *arg)
 395 {
 396         return _hypercall2(int, sched_op, cmd, arg);
 397 }
 398
 399 static inline long
 400 HYPERVISOR_set_timer_op(u64 timeout)
 401 {
 402         unsigned long timeout_hi = (unsigned long)(timeout>>32);
 403         unsigned long timeout_lo = (unsigned long)timeout;
 404         return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi);
 405 }
 406
 407 static inline int
 408 HYPERVISOR_mca(struct xen_mc *mc_op)
 409 {
 410         mc_op->interface_version = XEN_MCA_INTERFACE_VERSION;
 411         return _hypercall1(int, mca, mc_op);
 412 }
 413
 414 static inline int
 415 HYPERVISOR_platform_op(struct xen_platform_op *op)
 416 {
 417         op->interface_version = XENPF_INTERFACE_VERSION;
 418         return _hypercall1(int, platform_op, op);
 419 }
 420
 421 static inline long
 422 HYPERVISOR_memory_op(unsigned int cmd, void *arg)
 423 {
 424         return _hypercall2(long, memory_op, cmd, arg);
 425 }
 426
 427 static inline int
 428 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls)
 429 {
 430         return _hypercall2(int, multicall, call_list, nr_calls);
 431 }
 432
 433 static inline int
 434 HYPERVISOR_event_channel_op(int cmd, void *arg)
 435 {
 436         return _hypercall2(int, event_channel_op, cmd, arg);
 437 }
 438
 439 static __always_inline int
 440 HYPERVISOR_xen_version(int cmd, void *arg)
 441 {
 442         return _hypercall2(int, xen_version, cmd, arg);
 443 }
 444
 445 static inline int
 446 HYPERVISOR_console_io(int cmd, int count, char *str)
 447 {
 448         return _hypercall3(int, console_io, cmd, count, str);
 449 }
 450
 451 static inline int
 452 HYPERVISOR_physdev_op(int cmd, void *arg)
 453 {
 454         return _hypercall2(int, physdev_op, cmd, arg);
 455 }
 456
 457 static inline int
 458 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
 459 {
 460         return _hypercall3(int, grant_table_op, cmd, uop, count);
 461 }
 462
 463 static inline int
 464 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type)
 465 {
 466         return _hypercall2(int, vm_assist, cmd, type);
 467 }
 468
 469 static inline int
 470 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args)
 471 {
 472         return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args);
 473 }
 474
 475 static inline int
 476 HYPERVISOR_suspend(unsigned long start_info_mfn)
 477 {
 478         struct sched_shutdown r = { .reason = SHUTDOWN_suspend };
 479
 480         /*
 481          * For a PV guest the tools require that the start_info mfn be
 482          * present in rdx/edx when the hypercall is made. Per the
 483          * hypercall calling convention this is the third hypercall
 484          * argument, which is start_info_mfn here.
 485          */
 486         return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn);
 487 }
 488
 489 static inline unsigned long __must_check
 490 HYPERVISOR_hvm_op(int op, void *arg)
 491 {
 492        return _hypercall2(unsigned long, hvm_op, op, arg);
 493 }
 494
 495 static inline int
 496 HYPERVISOR_xenpmu_op(unsigned int op, void *arg)
 497 {
 498         return _hypercall2(int, xenpmu_op, op, arg);
 499 }
 500
 501 static inline int
 502 HYPERVISOR_dm_op(
 503         domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs)
 504 {
 505         int ret;
 506         __xen_stac();
 507         ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs);
 508         __xen_clac();
 509         return ret;
 510 }
 511
 512 #endif /* _ASM_X86_XEN_HYPERCALL_H */