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 43 #include <trace/events/xen.h> 44 45 #include <asm/page.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 __always_inline void __xen_stac(void) 221 { 222 /* 223 * Suppress objtool seeing the STAC/CLAC and getting confused about it 224 * calling random code with AC=1. 225 */ 226 asm volatile(ANNOTATE_IGNORE_ALTERNATIVE 227 ASM_STAC ::: "memory", "flags"); 228 } 229 230 static __always_inline void __xen_clac(void) 231 { 232 asm volatile(ANNOTATE_IGNORE_ALTERNATIVE 233 ASM_CLAC ::: "memory", "flags"); 234 } 235 236 static inline long 237 privcmd_call(unsigned int call, 238 unsigned long a1, unsigned long a2, 239 unsigned long a3, unsigned long a4, 240 unsigned long a5) 241 { 242 long res; 243 244 __xen_stac(); 245 res = xen_single_call(call, a1, a2, a3, a4, a5); 246 __xen_clac(); 247 248 return res; 249 } 250 251 static inline int 252 HYPERVISOR_set_trap_table(struct trap_info *table) 253 { 254 return _hypercall1(int, set_trap_table, table); 255 } 256 257 static inline int 258 HYPERVISOR_mmu_update(struct mmu_update *req, int count, 259 int *success_count, domid_t domid) 260 { 261 return _hypercall4(int, mmu_update, req, count, success_count, domid); 262 } 263 264 static inline int 265 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count, 266 int *success_count, domid_t domid) 267 { 268 return _hypercall4(int, mmuext_op, op, count, success_count, domid); 269 } 270 271 static inline int 272 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries) 273 { 274 return _hypercall2(int, set_gdt, frame_list, entries); 275 } 276 277 static inline int 278 HYPERVISOR_callback_op(int cmd, void *arg) 279 { 280 return _hypercall2(int, callback_op, cmd, arg); 281 } 282 283 static inline int 284 HYPERVISOR_sched_op(int cmd, void *arg) 285 { 286 return _hypercall2(int, sched_op, cmd, arg); 287 } 288 289 static inline long 290 HYPERVISOR_set_timer_op(u64 timeout) 291 { 292 unsigned long timeout_hi = (unsigned long)(timeout>>32); 293 unsigned long timeout_lo = (unsigned long)timeout; 294 return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi); 295 } 296 297 static inline int 298 HYPERVISOR_mca(struct xen_mc *mc_op) 299 { 300 mc_op->interface_version = XEN_MCA_INTERFACE_VERSION; 301 return _hypercall1(int, mca, mc_op); 302 } 303 304 static inline int 305 HYPERVISOR_platform_op(struct xen_platform_op *op) 306 { 307 op->interface_version = XENPF_INTERFACE_VERSION; 308 return _hypercall1(int, platform_op, op); 309 } 310 311 static inline int 312 HYPERVISOR_set_debugreg(int reg, unsigned long value) 313 { 314 return _hypercall2(int, set_debugreg, reg, value); 315 } 316 317 static inline unsigned long 318 HYPERVISOR_get_debugreg(int reg) 319 { 320 return _hypercall1(unsigned long, get_debugreg, reg); 321 } 322 323 static inline int 324 HYPERVISOR_update_descriptor(u64 ma, u64 desc) 325 { 326 if (sizeof(u64) == sizeof(long)) 327 return _hypercall2(int, update_descriptor, ma, desc); 328 return _hypercall4(int, update_descriptor, ma, ma>>32, desc, desc>>32); 329 } 330 331 static inline long 332 HYPERVISOR_memory_op(unsigned int cmd, void *arg) 333 { 334 return _hypercall2(long, memory_op, cmd, arg); 335 } 336 337 static inline int 338 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls) 339 { 340 return _hypercall2(int, multicall, call_list, nr_calls); 341 } 342 343 static inline int 344 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val, 345 unsigned long flags) 346 { 347 if (sizeof(new_val) == sizeof(long)) 348 return _hypercall3(int, update_va_mapping, va, 349 new_val.pte, flags); 350 else 351 return _hypercall4(int, update_va_mapping, va, 352 new_val.pte, new_val.pte >> 32, flags); 353 } 354 355 static inline int 356 HYPERVISOR_event_channel_op(int cmd, void *arg) 357 { 358 return _hypercall2(int, event_channel_op, cmd, arg); 359 } 360 361 static inline int 362 HYPERVISOR_xen_version(int cmd, void *arg) 363 { 364 return _hypercall2(int, xen_version, cmd, arg); 365 } 366 367 static inline int 368 HYPERVISOR_console_io(int cmd, int count, char *str) 369 { 370 return _hypercall3(int, console_io, cmd, count, str); 371 } 372 373 static inline int 374 HYPERVISOR_physdev_op(int cmd, void *arg) 375 { 376 return _hypercall2(int, physdev_op, cmd, arg); 377 } 378 379 static inline int 380 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count) 381 { 382 return _hypercall3(int, grant_table_op, cmd, uop, count); 383 } 384 385 static inline int 386 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type) 387 { 388 return _hypercall2(int, vm_assist, cmd, type); 389 } 390 391 static inline int 392 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args) 393 { 394 return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args); 395 } 396 397 #ifdef CONFIG_X86_64 398 static inline int 399 HYPERVISOR_set_segment_base(int reg, unsigned long value) 400 { 401 return _hypercall2(int, set_segment_base, reg, value); 402 } 403 #endif 404 405 static inline int 406 HYPERVISOR_suspend(unsigned long start_info_mfn) 407 { 408 struct sched_shutdown r = { .reason = SHUTDOWN_suspend }; 409 410 /* 411 * For a PV guest the tools require that the start_info mfn be 412 * present in rdx/edx when the hypercall is made. Per the 413 * hypercall calling convention this is the third hypercall 414 * argument, which is start_info_mfn here. 415 */ 416 return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn); 417 } 418 419 static inline unsigned long __must_check 420 HYPERVISOR_hvm_op(int op, void *arg) 421 { 422 return _hypercall2(unsigned long, hvm_op, op, arg); 423 } 424 425 static inline int 426 HYPERVISOR_tmem_op( 427 struct tmem_op *op) 428 { 429 return _hypercall1(int, tmem_op, op); 430 } 431 432 static inline int 433 HYPERVISOR_xenpmu_op(unsigned int op, void *arg) 434 { 435 return _hypercall2(int, xenpmu_op, op, arg); 436 } 437 438 static inline int 439 HYPERVISOR_dm_op( 440 domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs) 441 { 442 int ret; 443 __xen_stac(); 444 ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs); 445 __xen_clac(); 446 return ret; 447 } 448 449 static inline void 450 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set) 451 { 452 mcl->op = __HYPERVISOR_fpu_taskswitch; 453 mcl->args[0] = set; 454 455 trace_xen_mc_entry(mcl, 1); 456 } 457 458 static inline void 459 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va, 460 pte_t new_val, unsigned long flags) 461 { 462 mcl->op = __HYPERVISOR_update_va_mapping; 463 mcl->args[0] = va; 464 if (sizeof(new_val) == sizeof(long)) { 465 mcl->args[1] = new_val.pte; 466 mcl->args[2] = flags; 467 } else { 468 mcl->args[1] = new_val.pte; 469 mcl->args[2] = new_val.pte >> 32; 470 mcl->args[3] = flags; 471 } 472 473 trace_xen_mc_entry(mcl, sizeof(new_val) == sizeof(long) ? 3 : 4); 474 } 475 476 static inline void 477 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr, 478 struct desc_struct desc) 479 { 480 mcl->op = __HYPERVISOR_update_descriptor; 481 if (sizeof(maddr) == sizeof(long)) { 482 mcl->args[0] = maddr; 483 mcl->args[1] = *(unsigned long *)&desc; 484 } else { 485 u32 *p = (u32 *)&desc; 486 487 mcl->args[0] = maddr; 488 mcl->args[1] = maddr >> 32; 489 mcl->args[2] = *p++; 490 mcl->args[3] = *p; 491 } 492 493 trace_xen_mc_entry(mcl, sizeof(maddr) == sizeof(long) ? 2 : 4); 494 } 495 496 static inline void 497 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req, 498 int count, int *success_count, domid_t domid) 499 { 500 mcl->op = __HYPERVISOR_mmu_update; 501 mcl->args[0] = (unsigned long)req; 502 mcl->args[1] = count; 503 mcl->args[2] = (unsigned long)success_count; 504 mcl->args[3] = domid; 505 506 trace_xen_mc_entry(mcl, 4); 507 } 508 509 static inline void 510 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, 511 int *success_count, domid_t domid) 512 { 513 mcl->op = __HYPERVISOR_mmuext_op; 514 mcl->args[0] = (unsigned long)op; 515 mcl->args[1] = count; 516 mcl->args[2] = (unsigned long)success_count; 517 mcl->args[3] = domid; 518 519 trace_xen_mc_entry(mcl, 4); 520 } 521 522 static inline void 523 MULTI_stack_switch(struct multicall_entry *mcl, 524 unsigned long ss, unsigned long esp) 525 { 526 mcl->op = __HYPERVISOR_stack_switch; 527 mcl->args[0] = ss; 528 mcl->args[1] = esp; 529 530 trace_xen_mc_entry(mcl, 2); 531 } 532 533 #endif /* _ASM_X86_XEN_HYPERCALL_H */ 534