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