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