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 */ 513