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 \ 98 __stringify(.global STATIC_CALL_KEY(xen_hypercall);) 99 #endif 100 101 #define __HYPERCALL \ 102 __ADDRESSABLE_xen_hypercall \ 103 __stringify(call STATIC_CALL_TRAMP(xen_hypercall)) 104 105 #define __HYPERCALL_ENTRY(x) "a" (x) 106 107 #ifdef CONFIG_X86_32 108 #define __HYPERCALL_RETREG "eax" 109 #define __HYPERCALL_ARG1REG "ebx" 110 #define __HYPERCALL_ARG2REG "ecx" 111 #define __HYPERCALL_ARG3REG "edx" 112 #define __HYPERCALL_ARG4REG "esi" 113 #define __HYPERCALL_ARG5REG "edi" 114 #else 115 #define __HYPERCALL_RETREG "rax" 116 #define __HYPERCALL_ARG1REG "rdi" 117 #define __HYPERCALL_ARG2REG "rsi" 118 #define __HYPERCALL_ARG3REG "rdx" 119 #define __HYPERCALL_ARG4REG "r10" 120 #define __HYPERCALL_ARG5REG "r8" 121 #endif 122 123 #define __HYPERCALL_DECLS \ 124 register unsigned long __res asm(__HYPERCALL_RETREG); \ 125 register unsigned long __arg1 asm(__HYPERCALL_ARG1REG) = __arg1; \ 126 register unsigned long __arg2 asm(__HYPERCALL_ARG2REG) = __arg2; \ 127 register unsigned long __arg3 asm(__HYPERCALL_ARG3REG) = __arg3; \ 128 register unsigned long __arg4 asm(__HYPERCALL_ARG4REG) = __arg4; \ 129 register unsigned long __arg5 asm(__HYPERCALL_ARG5REG) = __arg5; 130 131 #define __HYPERCALL_0PARAM "=r" (__res), ASM_CALL_CONSTRAINT 132 #define __HYPERCALL_1PARAM __HYPERCALL_0PARAM, "+r" (__arg1) 133 #define __HYPERCALL_2PARAM __HYPERCALL_1PARAM, "+r" (__arg2) 134 #define __HYPERCALL_3PARAM __HYPERCALL_2PARAM, "+r" (__arg3) 135 #define __HYPERCALL_4PARAM __HYPERCALL_3PARAM, "+r" (__arg4) 136 #define __HYPERCALL_5PARAM __HYPERCALL_4PARAM, "+r" (__arg5) 137 138 #define __HYPERCALL_0ARG() 139 #define __HYPERCALL_1ARG(a1) \ 140 __HYPERCALL_0ARG() __arg1 = (unsigned long)(a1); 141 #define __HYPERCALL_2ARG(a1,a2) \ 142 __HYPERCALL_1ARG(a1) __arg2 = (unsigned long)(a2); 143 #define __HYPERCALL_3ARG(a1,a2,a3) \ 144 __HYPERCALL_2ARG(a1,a2) __arg3 = (unsigned long)(a3); 145 #define __HYPERCALL_4ARG(a1,a2,a3,a4) \ 146 __HYPERCALL_3ARG(a1,a2,a3) __arg4 = (unsigned long)(a4); 147 #define __HYPERCALL_5ARG(a1,a2,a3,a4,a5) \ 148 __HYPERCALL_4ARG(a1,a2,a3,a4) __arg5 = (unsigned long)(a5); 149 150 #define __HYPERCALL_CLOBBER5 "memory" 151 #define __HYPERCALL_CLOBBER4 __HYPERCALL_CLOBBER5, __HYPERCALL_ARG5REG 152 #define __HYPERCALL_CLOBBER3 __HYPERCALL_CLOBBER4, __HYPERCALL_ARG4REG 153 #define __HYPERCALL_CLOBBER2 __HYPERCALL_CLOBBER3, __HYPERCALL_ARG3REG 154 #define __HYPERCALL_CLOBBER1 __HYPERCALL_CLOBBER2, __HYPERCALL_ARG2REG 155 #define __HYPERCALL_CLOBBER0 __HYPERCALL_CLOBBER1, __HYPERCALL_ARG1REG 156 157 #define _hypercall0(type, name) \ 158 ({ \ 159 __HYPERCALL_DECLS; \ 160 __HYPERCALL_0ARG(); \ 161 asm volatile (__HYPERCALL \ 162 : __HYPERCALL_0PARAM \ 163 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \ 164 : __HYPERCALL_CLOBBER0); \ 165 (type)__res; \ 166 }) 167 168 #define _hypercall1(type, name, a1) \ 169 ({ \ 170 __HYPERCALL_DECLS; \ 171 __HYPERCALL_1ARG(a1); \ 172 asm volatile (__HYPERCALL \ 173 : __HYPERCALL_1PARAM \ 174 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \ 175 : __HYPERCALL_CLOBBER1); \ 176 (type)__res; \ 177 }) 178 179 #define _hypercall2(type, name, a1, a2) \ 180 ({ \ 181 __HYPERCALL_DECLS; \ 182 __HYPERCALL_2ARG(a1, a2); \ 183 asm volatile (__HYPERCALL \ 184 : __HYPERCALL_2PARAM \ 185 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \ 186 : __HYPERCALL_CLOBBER2); \ 187 (type)__res; \ 188 }) 189 190 #define _hypercall3(type, name, a1, a2, a3) \ 191 ({ \ 192 __HYPERCALL_DECLS; \ 193 __HYPERCALL_3ARG(a1, a2, a3); \ 194 asm volatile (__HYPERCALL \ 195 : __HYPERCALL_3PARAM \ 196 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \ 197 : __HYPERCALL_CLOBBER3); \ 198 (type)__res; \ 199 }) 200 201 #define _hypercall4(type, name, a1, a2, a3, a4) \ 202 ({ \ 203 __HYPERCALL_DECLS; \ 204 __HYPERCALL_4ARG(a1, a2, a3, a4); \ 205 asm volatile (__HYPERCALL \ 206 : __HYPERCALL_4PARAM \ 207 : __HYPERCALL_ENTRY(__HYPERVISOR_ ## name) \ 208 : __HYPERCALL_CLOBBER4); \ 209 (type)__res; \ 210 }) 211 212 static inline long 213 xen_single_call(unsigned int call, 214 unsigned long a1, unsigned long a2, 215 unsigned long a3, unsigned long a4, 216 unsigned long a5) 217 { 218 __HYPERCALL_DECLS; 219 __HYPERCALL_5ARG(a1, a2, a3, a4, a5); 220 221 asm volatile(__HYPERCALL 222 : __HYPERCALL_5PARAM 223 : __HYPERCALL_ENTRY(call) 224 : __HYPERCALL_CLOBBER5); 225 226 return (long)__res; 227 } 228 229 static __always_inline void __xen_stac(void) 230 { 231 /* 232 * Suppress objtool seeing the STAC/CLAC and getting confused about it 233 * calling random code with AC=1. 234 */ 235 asm volatile(ASM_STAC_UNSAFE ::: "memory", "flags"); 236 } 237 238 static __always_inline void __xen_clac(void) 239 { 240 asm volatile(ASM_CLAC_UNSAFE ::: "memory", "flags"); 241 } 242 243 static inline long 244 privcmd_call(unsigned int call, 245 unsigned long a1, unsigned long a2, 246 unsigned long a3, unsigned long a4, 247 unsigned long a5) 248 { 249 long res; 250 251 __xen_stac(); 252 res = xen_single_call(call, a1, a2, a3, a4, a5); 253 __xen_clac(); 254 255 return res; 256 } 257 258 #ifdef CONFIG_XEN_PV 259 static inline int 260 HYPERVISOR_set_trap_table(struct trap_info *table) 261 { 262 return _hypercall1(int, set_trap_table, table); 263 } 264 265 static inline int 266 HYPERVISOR_mmu_update(struct mmu_update *req, int count, 267 int *success_count, domid_t domid) 268 { 269 return _hypercall4(int, mmu_update, req, count, success_count, domid); 270 } 271 272 static inline int 273 HYPERVISOR_mmuext_op(struct mmuext_op *op, int count, 274 int *success_count, domid_t domid) 275 { 276 return _hypercall4(int, mmuext_op, op, count, success_count, domid); 277 } 278 279 static inline int 280 HYPERVISOR_set_gdt(unsigned long *frame_list, int entries) 281 { 282 return _hypercall2(int, set_gdt, frame_list, entries); 283 } 284 285 static inline int 286 HYPERVISOR_callback_op(int cmd, void *arg) 287 { 288 return _hypercall2(int, callback_op, cmd, arg); 289 } 290 291 static __always_inline int 292 HYPERVISOR_set_debugreg(int reg, unsigned long value) 293 { 294 return _hypercall2(int, set_debugreg, reg, value); 295 } 296 297 static __always_inline unsigned long 298 HYPERVISOR_get_debugreg(int reg) 299 { 300 return _hypercall1(unsigned long, get_debugreg, reg); 301 } 302 303 static inline int 304 HYPERVISOR_update_descriptor(u64 ma, u64 desc) 305 { 306 return _hypercall2(int, update_descriptor, ma, desc); 307 } 308 309 static inline int 310 HYPERVISOR_update_va_mapping(unsigned long va, pte_t new_val, 311 unsigned long flags) 312 { 313 return _hypercall3(int, update_va_mapping, va, new_val.pte, flags); 314 } 315 316 static inline int 317 HYPERVISOR_set_segment_base(int reg, unsigned long value) 318 { 319 return _hypercall2(int, set_segment_base, reg, value); 320 } 321 322 static inline void 323 MULTI_fpu_taskswitch(struct multicall_entry *mcl, int set) 324 { 325 mcl->op = __HYPERVISOR_fpu_taskswitch; 326 mcl->args[0] = set; 327 328 trace_xen_mc_entry(mcl, 1); 329 } 330 331 static inline void 332 MULTI_update_va_mapping(struct multicall_entry *mcl, unsigned long va, 333 pte_t new_val, unsigned long flags) 334 { 335 mcl->op = __HYPERVISOR_update_va_mapping; 336 mcl->args[0] = va; 337 mcl->args[1] = new_val.pte; 338 mcl->args[2] = flags; 339 340 trace_xen_mc_entry(mcl, 3); 341 } 342 343 static inline void 344 MULTI_update_descriptor(struct multicall_entry *mcl, u64 maddr, 345 struct desc_struct desc) 346 { 347 mcl->op = __HYPERVISOR_update_descriptor; 348 mcl->args[0] = maddr; 349 mcl->args[1] = *(unsigned long *)&desc; 350 351 trace_xen_mc_entry(mcl, 2); 352 } 353 354 static inline void 355 MULTI_mmu_update(struct multicall_entry *mcl, struct mmu_update *req, 356 int count, int *success_count, domid_t domid) 357 { 358 mcl->op = __HYPERVISOR_mmu_update; 359 mcl->args[0] = (unsigned long)req; 360 mcl->args[1] = count; 361 mcl->args[2] = (unsigned long)success_count; 362 mcl->args[3] = domid; 363 364 trace_xen_mc_entry(mcl, 4); 365 } 366 367 static inline void 368 MULTI_mmuext_op(struct multicall_entry *mcl, struct mmuext_op *op, int count, 369 int *success_count, domid_t domid) 370 { 371 mcl->op = __HYPERVISOR_mmuext_op; 372 mcl->args[0] = (unsigned long)op; 373 mcl->args[1] = count; 374 mcl->args[2] = (unsigned long)success_count; 375 mcl->args[3] = domid; 376 377 trace_xen_mc_entry(mcl, 4); 378 } 379 380 static inline void 381 MULTI_stack_switch(struct multicall_entry *mcl, 382 unsigned long ss, unsigned long esp) 383 { 384 mcl->op = __HYPERVISOR_stack_switch; 385 mcl->args[0] = ss; 386 mcl->args[1] = esp; 387 388 trace_xen_mc_entry(mcl, 2); 389 } 390 #endif 391 392 static __always_inline int 393 HYPERVISOR_sched_op(int cmd, void *arg) 394 { 395 return _hypercall2(int, sched_op, cmd, arg); 396 } 397 398 static inline long 399 HYPERVISOR_set_timer_op(u64 timeout) 400 { 401 unsigned long timeout_hi = (unsigned long)(timeout>>32); 402 unsigned long timeout_lo = (unsigned long)timeout; 403 return _hypercall2(long, set_timer_op, timeout_lo, timeout_hi); 404 } 405 406 static inline int 407 HYPERVISOR_mca(struct xen_mc *mc_op) 408 { 409 mc_op->interface_version = XEN_MCA_INTERFACE_VERSION; 410 return _hypercall1(int, mca, mc_op); 411 } 412 413 static inline int 414 HYPERVISOR_platform_op(struct xen_platform_op *op) 415 { 416 op->interface_version = XENPF_INTERFACE_VERSION; 417 return _hypercall1(int, platform_op, op); 418 } 419 420 static inline long 421 HYPERVISOR_memory_op(unsigned int cmd, void *arg) 422 { 423 return _hypercall2(long, memory_op, cmd, arg); 424 } 425 426 static inline int 427 HYPERVISOR_multicall(void *call_list, uint32_t nr_calls) 428 { 429 return _hypercall2(int, multicall, call_list, nr_calls); 430 } 431 432 static inline int 433 HYPERVISOR_event_channel_op(int cmd, void *arg) 434 { 435 return _hypercall2(int, event_channel_op, cmd, arg); 436 } 437 438 static __always_inline int 439 HYPERVISOR_xen_version(int cmd, void *arg) 440 { 441 return _hypercall2(int, xen_version, cmd, arg); 442 } 443 444 static inline int 445 HYPERVISOR_console_io(int cmd, int count, char *str) 446 { 447 return _hypercall3(int, console_io, cmd, count, str); 448 } 449 450 static inline int 451 HYPERVISOR_physdev_op(int cmd, void *arg) 452 { 453 return _hypercall2(int, physdev_op, cmd, arg); 454 } 455 456 static inline int 457 HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count) 458 { 459 return _hypercall3(int, grant_table_op, cmd, uop, count); 460 } 461 462 static inline int 463 HYPERVISOR_vm_assist(unsigned int cmd, unsigned int type) 464 { 465 return _hypercall2(int, vm_assist, cmd, type); 466 } 467 468 static inline int 469 HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args) 470 { 471 return _hypercall3(int, vcpu_op, cmd, vcpuid, extra_args); 472 } 473 474 static inline int 475 HYPERVISOR_suspend(unsigned long start_info_mfn) 476 { 477 struct sched_shutdown r = { .reason = SHUTDOWN_suspend }; 478 479 /* 480 * For a PV guest the tools require that the start_info mfn be 481 * present in rdx/edx when the hypercall is made. Per the 482 * hypercall calling convention this is the third hypercall 483 * argument, which is start_info_mfn here. 484 */ 485 return _hypercall3(int, sched_op, SCHEDOP_shutdown, &r, start_info_mfn); 486 } 487 488 static inline unsigned long __must_check 489 HYPERVISOR_hvm_op(int op, void *arg) 490 { 491 return _hypercall2(unsigned long, hvm_op, op, arg); 492 } 493 494 static inline int 495 HYPERVISOR_xenpmu_op(unsigned int op, void *arg) 496 { 497 return _hypercall2(int, xenpmu_op, op, arg); 498 } 499 500 static inline int 501 HYPERVISOR_dm_op( 502 domid_t dom, unsigned int nr_bufs, struct xen_dm_op_buf *bufs) 503 { 504 int ret; 505 __xen_stac(); 506 ret = _hypercall3(int, dm_op, dom, nr_bufs, bufs); 507 __xen_clac(); 508 return ret; 509 } 510 511 #endif /* _ASM_X86_XEN_HYPERCALL_H */ 512