1 /* Paravirtualization interfaces 2 Copyright (C) 2006 Rusty Russell IBM Corporation 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 2 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; if not, write to the Free Software 16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 18 2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc 19 */ 20 21 #include <linux/errno.h> 22 #include <linux/module.h> 23 #include <linux/efi.h> 24 #include <linux/bcd.h> 25 #include <linux/highmem.h> 26 27 #include <asm/bug.h> 28 #include <asm/paravirt.h> 29 #include <asm/desc.h> 30 #include <asm/setup.h> 31 #include <asm/pgtable.h> 32 #include <asm/time.h> 33 #include <asm/pgalloc.h> 34 #include <asm/irq.h> 35 #include <asm/delay.h> 36 #include <asm/fixmap.h> 37 #include <asm/apic.h> 38 #include <asm/tlbflush.h> 39 #include <asm/timer.h> 40 41 /* nop stub */ 42 void _paravirt_nop(void) 43 { 44 } 45 46 /* identity function, which can be inlined */ 47 u32 _paravirt_ident_32(u32 x) 48 { 49 return x; 50 } 51 52 u64 _paravirt_ident_64(u64 x) 53 { 54 return x; 55 } 56 57 static void __init default_banner(void) 58 { 59 printk(KERN_INFO "Booting paravirtualized kernel on %s\n", 60 pv_info.name); 61 } 62 63 char *memory_setup(void) 64 { 65 return pv_init_ops.memory_setup(); 66 } 67 68 /* Simple instruction patching code. */ 69 #define DEF_NATIVE(ops, name, code) \ 70 extern const char start_##ops##_##name[], end_##ops##_##name[]; \ 71 asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":") 72 73 /* Undefined instruction for dealing with missing ops pointers. */ 74 static const unsigned char ud2a[] = { 0x0f, 0x0b }; 75 76 unsigned paravirt_patch_nop(void) 77 { 78 return 0; 79 } 80 81 unsigned paravirt_patch_ignore(unsigned len) 82 { 83 return len; 84 } 85 86 struct branch { 87 unsigned char opcode; 88 u32 delta; 89 } __attribute__((packed)); 90 91 unsigned paravirt_patch_call(void *insnbuf, 92 const void *target, u16 tgt_clobbers, 93 unsigned long addr, u16 site_clobbers, 94 unsigned len) 95 { 96 struct branch *b = insnbuf; 97 unsigned long delta = (unsigned long)target - (addr+5); 98 99 if (tgt_clobbers & ~site_clobbers) 100 return len; /* target would clobber too much for this site */ 101 if (len < 5) 102 return len; /* call too long for patch site */ 103 104 b->opcode = 0xe8; /* call */ 105 b->delta = delta; 106 BUILD_BUG_ON(sizeof(*b) != 5); 107 108 return 5; 109 } 110 111 unsigned paravirt_patch_jmp(void *insnbuf, const void *target, 112 unsigned long addr, unsigned len) 113 { 114 struct branch *b = insnbuf; 115 unsigned long delta = (unsigned long)target - (addr+5); 116 117 if (len < 5) 118 return len; /* call too long for patch site */ 119 120 b->opcode = 0xe9; /* jmp */ 121 b->delta = delta; 122 123 return 5; 124 } 125 126 /* Neat trick to map patch type back to the call within the 127 * corresponding structure. */ 128 static void *get_call_destination(u8 type) 129 { 130 struct paravirt_patch_template tmpl = { 131 .pv_init_ops = pv_init_ops, 132 .pv_time_ops = pv_time_ops, 133 .pv_cpu_ops = pv_cpu_ops, 134 .pv_irq_ops = pv_irq_ops, 135 .pv_apic_ops = pv_apic_ops, 136 .pv_mmu_ops = pv_mmu_ops, 137 #ifdef CONFIG_PARAVIRT_SPINLOCKS 138 .pv_lock_ops = pv_lock_ops, 139 #endif 140 }; 141 return *((void **)&tmpl + type); 142 } 143 144 unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, 145 unsigned long addr, unsigned len) 146 { 147 void *opfunc = get_call_destination(type); 148 unsigned ret; 149 150 if (opfunc == NULL) 151 /* If there's no function, patch it with a ud2a (BUG) */ 152 ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a)); 153 else if (opfunc == _paravirt_nop) 154 /* If the operation is a nop, then nop the callsite */ 155 ret = paravirt_patch_nop(); 156 157 /* identity functions just return their single argument */ 158 else if (opfunc == _paravirt_ident_32) 159 ret = paravirt_patch_ident_32(insnbuf, len); 160 else if (opfunc == _paravirt_ident_64) 161 ret = paravirt_patch_ident_64(insnbuf, len); 162 163 else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || 164 type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || 165 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) || 166 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64)) 167 /* If operation requires a jmp, then jmp */ 168 ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len); 169 else 170 /* Otherwise call the function; assume target could 171 clobber any caller-save reg */ 172 ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY, 173 addr, clobbers, len); 174 175 return ret; 176 } 177 178 unsigned paravirt_patch_insns(void *insnbuf, unsigned len, 179 const char *start, const char *end) 180 { 181 unsigned insn_len = end - start; 182 183 if (insn_len > len || start == NULL) 184 insn_len = len; 185 else 186 memcpy(insnbuf, start, insn_len); 187 188 return insn_len; 189 } 190 191 void init_IRQ(void) 192 { 193 pv_irq_ops.init_IRQ(); 194 } 195 196 static void native_flush_tlb(void) 197 { 198 __native_flush_tlb(); 199 } 200 201 /* 202 * Global pages have to be flushed a bit differently. Not a real 203 * performance problem because this does not happen often. 204 */ 205 static void native_flush_tlb_global(void) 206 { 207 __native_flush_tlb_global(); 208 } 209 210 static void native_flush_tlb_single(unsigned long addr) 211 { 212 __native_flush_tlb_single(addr); 213 } 214 215 /* These are in entry.S */ 216 extern void native_iret(void); 217 extern void native_irq_enable_sysexit(void); 218 extern void native_usergs_sysret32(void); 219 extern void native_usergs_sysret64(void); 220 221 static int __init print_banner(void) 222 { 223 pv_init_ops.banner(); 224 return 0; 225 } 226 core_initcall(print_banner); 227 228 static struct resource reserve_ioports = { 229 .start = 0, 230 .end = IO_SPACE_LIMIT, 231 .name = "paravirt-ioport", 232 .flags = IORESOURCE_IO | IORESOURCE_BUSY, 233 }; 234 235 /* 236 * Reserve the whole legacy IO space to prevent any legacy drivers 237 * from wasting time probing for their hardware. This is a fairly 238 * brute-force approach to disabling all non-virtual drivers. 239 * 240 * Note that this must be called very early to have any effect. 241 */ 242 int paravirt_disable_iospace(void) 243 { 244 return request_resource(&ioport_resource, &reserve_ioports); 245 } 246 247 static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE; 248 249 static inline void enter_lazy(enum paravirt_lazy_mode mode) 250 { 251 BUG_ON(percpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE); 252 253 percpu_write(paravirt_lazy_mode, mode); 254 } 255 256 static void leave_lazy(enum paravirt_lazy_mode mode) 257 { 258 BUG_ON(percpu_read(paravirt_lazy_mode) != mode); 259 260 percpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE); 261 } 262 263 void paravirt_enter_lazy_mmu(void) 264 { 265 enter_lazy(PARAVIRT_LAZY_MMU); 266 } 267 268 void paravirt_leave_lazy_mmu(void) 269 { 270 leave_lazy(PARAVIRT_LAZY_MMU); 271 } 272 273 void paravirt_start_context_switch(struct task_struct *prev) 274 { 275 BUG_ON(preemptible()); 276 277 if (percpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) { 278 arch_leave_lazy_mmu_mode(); 279 set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES); 280 } 281 enter_lazy(PARAVIRT_LAZY_CPU); 282 } 283 284 void paravirt_end_context_switch(struct task_struct *next) 285 { 286 BUG_ON(preemptible()); 287 288 leave_lazy(PARAVIRT_LAZY_CPU); 289 290 if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES)) 291 arch_enter_lazy_mmu_mode(); 292 } 293 294 enum paravirt_lazy_mode paravirt_get_lazy_mode(void) 295 { 296 if (in_interrupt()) 297 return PARAVIRT_LAZY_NONE; 298 299 return percpu_read(paravirt_lazy_mode); 300 } 301 302 void arch_flush_lazy_mmu_mode(void) 303 { 304 preempt_disable(); 305 306 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) { 307 arch_leave_lazy_mmu_mode(); 308 arch_enter_lazy_mmu_mode(); 309 } 310 311 preempt_enable(); 312 } 313 314 struct pv_info pv_info = { 315 .name = "bare hardware", 316 .paravirt_enabled = 0, 317 .kernel_rpl = 0, 318 .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */ 319 }; 320 321 struct pv_init_ops pv_init_ops = { 322 .patch = native_patch, 323 .banner = default_banner, 324 .arch_setup = paravirt_nop, 325 .memory_setup = machine_specific_memory_setup, 326 }; 327 328 struct pv_time_ops pv_time_ops = { 329 .time_init = hpet_time_init, 330 .get_wallclock = native_get_wallclock, 331 .set_wallclock = native_set_wallclock, 332 .sched_clock = native_sched_clock, 333 .get_tsc_khz = native_calibrate_tsc, 334 }; 335 336 struct pv_irq_ops pv_irq_ops = { 337 .init_IRQ = native_init_IRQ, 338 .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl), 339 .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl), 340 .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable), 341 .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable), 342 .safe_halt = native_safe_halt, 343 .halt = native_halt, 344 #ifdef CONFIG_X86_64 345 .adjust_exception_frame = paravirt_nop, 346 #endif 347 }; 348 349 struct pv_cpu_ops pv_cpu_ops = { 350 .cpuid = native_cpuid, 351 .get_debugreg = native_get_debugreg, 352 .set_debugreg = native_set_debugreg, 353 .clts = native_clts, 354 .read_cr0 = native_read_cr0, 355 .write_cr0 = native_write_cr0, 356 .read_cr4 = native_read_cr4, 357 .read_cr4_safe = native_read_cr4_safe, 358 .write_cr4 = native_write_cr4, 359 #ifdef CONFIG_X86_64 360 .read_cr8 = native_read_cr8, 361 .write_cr8 = native_write_cr8, 362 #endif 363 .wbinvd = native_wbinvd, 364 .read_msr = native_read_msr_safe, 365 .read_msr_amd = native_read_msr_amd_safe, 366 .write_msr = native_write_msr_safe, 367 .read_tsc = native_read_tsc, 368 .read_pmc = native_read_pmc, 369 .read_tscp = native_read_tscp, 370 .load_tr_desc = native_load_tr_desc, 371 .set_ldt = native_set_ldt, 372 .load_gdt = native_load_gdt, 373 .load_idt = native_load_idt, 374 .store_gdt = native_store_gdt, 375 .store_idt = native_store_idt, 376 .store_tr = native_store_tr, 377 .load_tls = native_load_tls, 378 #ifdef CONFIG_X86_64 379 .load_gs_index = native_load_gs_index, 380 #endif 381 .write_ldt_entry = native_write_ldt_entry, 382 .write_gdt_entry = native_write_gdt_entry, 383 .write_idt_entry = native_write_idt_entry, 384 385 .alloc_ldt = paravirt_nop, 386 .free_ldt = paravirt_nop, 387 388 .load_sp0 = native_load_sp0, 389 390 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) 391 .irq_enable_sysexit = native_irq_enable_sysexit, 392 #endif 393 #ifdef CONFIG_X86_64 394 #ifdef CONFIG_IA32_EMULATION 395 .usergs_sysret32 = native_usergs_sysret32, 396 #endif 397 .usergs_sysret64 = native_usergs_sysret64, 398 #endif 399 .iret = native_iret, 400 .swapgs = native_swapgs, 401 402 .set_iopl_mask = native_set_iopl_mask, 403 .io_delay = native_io_delay, 404 405 .start_context_switch = paravirt_nop, 406 .end_context_switch = paravirt_nop, 407 }; 408 409 struct pv_apic_ops pv_apic_ops = { 410 #ifdef CONFIG_X86_LOCAL_APIC 411 .setup_boot_clock = setup_boot_APIC_clock, 412 .setup_secondary_clock = setup_secondary_APIC_clock, 413 .startup_ipi_hook = paravirt_nop, 414 #endif 415 }; 416 417 #if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE) 418 /* 32-bit pagetable entries */ 419 #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_32) 420 #else 421 /* 64-bit pagetable entries */ 422 #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64) 423 #endif 424 425 struct pv_mmu_ops pv_mmu_ops = { 426 #ifndef CONFIG_X86_64 427 .pagetable_setup_start = native_pagetable_setup_start, 428 .pagetable_setup_done = native_pagetable_setup_done, 429 #else 430 .pagetable_setup_start = paravirt_nop, 431 .pagetable_setup_done = paravirt_nop, 432 #endif 433 434 .read_cr2 = native_read_cr2, 435 .write_cr2 = native_write_cr2, 436 .read_cr3 = native_read_cr3, 437 .write_cr3 = native_write_cr3, 438 439 .flush_tlb_user = native_flush_tlb, 440 .flush_tlb_kernel = native_flush_tlb_global, 441 .flush_tlb_single = native_flush_tlb_single, 442 .flush_tlb_others = native_flush_tlb_others, 443 444 .pgd_alloc = __paravirt_pgd_alloc, 445 .pgd_free = paravirt_nop, 446 447 .alloc_pte = paravirt_nop, 448 .alloc_pmd = paravirt_nop, 449 .alloc_pmd_clone = paravirt_nop, 450 .alloc_pud = paravirt_nop, 451 .release_pte = paravirt_nop, 452 .release_pmd = paravirt_nop, 453 .release_pud = paravirt_nop, 454 455 .set_pte = native_set_pte, 456 .set_pte_at = native_set_pte_at, 457 .set_pmd = native_set_pmd, 458 .pte_update = paravirt_nop, 459 .pte_update_defer = paravirt_nop, 460 461 .ptep_modify_prot_start = __ptep_modify_prot_start, 462 .ptep_modify_prot_commit = __ptep_modify_prot_commit, 463 464 #ifdef CONFIG_HIGHPTE 465 .kmap_atomic_pte = kmap_atomic, 466 #endif 467 468 #if PAGETABLE_LEVELS >= 3 469 #ifdef CONFIG_X86_PAE 470 .set_pte_atomic = native_set_pte_atomic, 471 .pte_clear = native_pte_clear, 472 .pmd_clear = native_pmd_clear, 473 #endif 474 .set_pud = native_set_pud, 475 476 .pmd_val = PTE_IDENT, 477 .make_pmd = PTE_IDENT, 478 479 #if PAGETABLE_LEVELS == 4 480 .pud_val = PTE_IDENT, 481 .make_pud = PTE_IDENT, 482 483 .set_pgd = native_set_pgd, 484 #endif 485 #endif /* PAGETABLE_LEVELS >= 3 */ 486 487 .pte_val = PTE_IDENT, 488 .pgd_val = PTE_IDENT, 489 490 .make_pte = PTE_IDENT, 491 .make_pgd = PTE_IDENT, 492 493 .dup_mmap = paravirt_nop, 494 .exit_mmap = paravirt_nop, 495 .activate_mm = paravirt_nop, 496 497 .lazy_mode = { 498 .enter = paravirt_nop, 499 .leave = paravirt_nop, 500 }, 501 502 .set_fixmap = native_set_fixmap, 503 }; 504 505 EXPORT_SYMBOL_GPL(pv_time_ops); 506 EXPORT_SYMBOL (pv_cpu_ops); 507 EXPORT_SYMBOL (pv_mmu_ops); 508 EXPORT_SYMBOL_GPL(pv_apic_ops); 509 EXPORT_SYMBOL_GPL(pv_info); 510 EXPORT_SYMBOL (pv_irq_ops); 511