paravirt.c revision 7032e8696726354d6180d8a2d17191f958cd93ae
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/arch_hooks.h> 32#include <asm/pgtable.h> 33#include <asm/time.h> 34#include <asm/pgalloc.h> 35#include <asm/irq.h> 36#include <asm/delay.h> 37#include <asm/fixmap.h> 38#include <asm/apic.h> 39#include <asm/tlbflush.h> 40#include <asm/timer.h> 41 42/* nop stub */ 43void _paravirt_nop(void) 44{ 45} 46 47/* identity function, which can be inlined */ 48u32 _paravirt_ident_32(u32 x) 49{ 50 return x; 51} 52 53u64 _paravirt_ident_64(u64 x) 54{ 55 return x; 56} 57 58static void __init default_banner(void) 59{ 60 printk(KERN_INFO "Booting paravirtualized kernel on %s\n", 61 pv_info.name); 62} 63 64char *memory_setup(void) 65{ 66 return pv_init_ops.memory_setup(); 67} 68 69/* Simple instruction patching code. */ 70#define DEF_NATIVE(ops, name, code) \ 71 extern const char start_##ops##_##name[], end_##ops##_##name[]; \ 72 asm("start_" #ops "_" #name ": " code "; end_" #ops "_" #name ":") 73 74/* Undefined instruction for dealing with missing ops pointers. */ 75static const unsigned char ud2a[] = { 0x0f, 0x0b }; 76 77unsigned paravirt_patch_nop(void) 78{ 79 return 0; 80} 81 82unsigned paravirt_patch_ignore(unsigned len) 83{ 84 return len; 85} 86 87struct branch { 88 unsigned char opcode; 89 u32 delta; 90} __attribute__((packed)); 91 92unsigned paravirt_patch_call(void *insnbuf, 93 const void *target, u16 tgt_clobbers, 94 unsigned long addr, u16 site_clobbers, 95 unsigned len) 96{ 97 struct branch *b = insnbuf; 98 unsigned long delta = (unsigned long)target - (addr+5); 99 100 if (tgt_clobbers & ~site_clobbers) 101 return len; /* target would clobber too much for this site */ 102 if (len < 5) 103 return len; /* call too long for patch site */ 104 105 b->opcode = 0xe8; /* call */ 106 b->delta = delta; 107 BUILD_BUG_ON(sizeof(*b) != 5); 108 109 return 5; 110} 111 112unsigned paravirt_patch_jmp(void *insnbuf, const void *target, 113 unsigned long addr, unsigned len) 114{ 115 struct branch *b = insnbuf; 116 unsigned long delta = (unsigned long)target - (addr+5); 117 118 if (len < 5) 119 return len; /* call too long for patch site */ 120 121 b->opcode = 0xe9; /* jmp */ 122 b->delta = delta; 123 124 return 5; 125} 126 127/* Neat trick to map patch type back to the call within the 128 * corresponding structure. */ 129static void *get_call_destination(u8 type) 130{ 131 struct paravirt_patch_template tmpl = { 132 .pv_init_ops = pv_init_ops, 133 .pv_time_ops = pv_time_ops, 134 .pv_cpu_ops = pv_cpu_ops, 135 .pv_irq_ops = pv_irq_ops, 136 .pv_apic_ops = pv_apic_ops, 137 .pv_mmu_ops = pv_mmu_ops, 138 .pv_lock_ops = pv_lock_ops, 139 }; 140 return *((void **)&tmpl + type); 141} 142 143unsigned paravirt_patch_default(u8 type, u16 clobbers, void *insnbuf, 144 unsigned long addr, unsigned len) 145{ 146 void *opfunc = get_call_destination(type); 147 unsigned ret; 148 149 if (opfunc == NULL) 150 /* If there's no function, patch it with a ud2a (BUG) */ 151 ret = paravirt_patch_insns(insnbuf, len, ud2a, ud2a+sizeof(ud2a)); 152 else if (opfunc == _paravirt_nop) 153 /* If the operation is a nop, then nop the callsite */ 154 ret = paravirt_patch_nop(); 155 156 /* identity functions just return their single argument */ 157 else if (opfunc == _paravirt_ident_32) 158 ret = paravirt_patch_ident_32(insnbuf, len); 159 else if (opfunc == _paravirt_ident_64) 160 ret = paravirt_patch_ident_64(insnbuf, len); 161 162 else if (type == PARAVIRT_PATCH(pv_cpu_ops.iret) || 163 type == PARAVIRT_PATCH(pv_cpu_ops.irq_enable_sysexit) || 164 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret32) || 165 type == PARAVIRT_PATCH(pv_cpu_ops.usergs_sysret64)) 166 /* If operation requires a jmp, then jmp */ 167 ret = paravirt_patch_jmp(insnbuf, opfunc, addr, len); 168 else 169 /* Otherwise call the function; assume target could 170 clobber any caller-save reg */ 171 ret = paravirt_patch_call(insnbuf, opfunc, CLBR_ANY, 172 addr, clobbers, len); 173 174 return ret; 175} 176 177unsigned paravirt_patch_insns(void *insnbuf, unsigned len, 178 const char *start, const char *end) 179{ 180 unsigned insn_len = end - start; 181 182 if (insn_len > len || start == NULL) 183 insn_len = len; 184 else 185 memcpy(insnbuf, start, insn_len); 186 187 return insn_len; 188} 189 190void init_IRQ(void) 191{ 192 pv_irq_ops.init_IRQ(); 193} 194 195static void native_flush_tlb(void) 196{ 197 __native_flush_tlb(); 198} 199 200/* 201 * Global pages have to be flushed a bit differently. Not a real 202 * performance problem because this does not happen often. 203 */ 204static void native_flush_tlb_global(void) 205{ 206 __native_flush_tlb_global(); 207} 208 209static void native_flush_tlb_single(unsigned long addr) 210{ 211 __native_flush_tlb_single(addr); 212} 213 214/* These are in entry.S */ 215extern void native_iret(void); 216extern void native_irq_enable_sysexit(void); 217extern void native_usergs_sysret32(void); 218extern void native_usergs_sysret64(void); 219 220static int __init print_banner(void) 221{ 222 pv_init_ops.banner(); 223 return 0; 224} 225core_initcall(print_banner); 226 227static struct resource reserve_ioports = { 228 .start = 0, 229 .end = IO_SPACE_LIMIT, 230 .name = "paravirt-ioport", 231 .flags = IORESOURCE_IO | IORESOURCE_BUSY, 232}; 233 234/* 235 * Reserve the whole legacy IO space to prevent any legacy drivers 236 * from wasting time probing for their hardware. This is a fairly 237 * brute-force approach to disabling all non-virtual drivers. 238 * 239 * Note that this must be called very early to have any effect. 240 */ 241int paravirt_disable_iospace(void) 242{ 243 return request_resource(&ioport_resource, &reserve_ioports); 244} 245 246static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE; 247 248static inline void enter_lazy(enum paravirt_lazy_mode mode) 249{ 250 BUG_ON(__get_cpu_var(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE); 251 BUG_ON(preemptible()); 252 253 __get_cpu_var(paravirt_lazy_mode) = mode; 254} 255 256void paravirt_leave_lazy(enum paravirt_lazy_mode mode) 257{ 258 BUG_ON(__get_cpu_var(paravirt_lazy_mode) != mode); 259 BUG_ON(preemptible()); 260 261 __get_cpu_var(paravirt_lazy_mode) = PARAVIRT_LAZY_NONE; 262} 263 264void paravirt_enter_lazy_mmu(void) 265{ 266 enter_lazy(PARAVIRT_LAZY_MMU); 267} 268 269void paravirt_leave_lazy_mmu(void) 270{ 271 paravirt_leave_lazy(PARAVIRT_LAZY_MMU); 272} 273 274void paravirt_enter_lazy_cpu(void) 275{ 276 enter_lazy(PARAVIRT_LAZY_CPU); 277} 278 279void paravirt_leave_lazy_cpu(void) 280{ 281 paravirt_leave_lazy(PARAVIRT_LAZY_CPU); 282} 283 284enum paravirt_lazy_mode paravirt_get_lazy_mode(void) 285{ 286 return __get_cpu_var(paravirt_lazy_mode); 287} 288 289void arch_flush_lazy_mmu_mode(void) 290{ 291 preempt_disable(); 292 293 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) { 294 WARN_ON(preempt_count() == 1); 295 arch_leave_lazy_mmu_mode(); 296 arch_enter_lazy_mmu_mode(); 297 } 298 299 preempt_enable(); 300} 301 302void arch_flush_lazy_cpu_mode(void) 303{ 304 preempt_disable(); 305 306 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_CPU) { 307 WARN_ON(preempt_count() == 1); 308 arch_leave_lazy_cpu_mode(); 309 arch_enter_lazy_cpu_mode(); 310 } 311 312 preempt_enable(); 313} 314 315struct pv_info pv_info = { 316 .name = "bare hardware", 317 .paravirt_enabled = 0, 318 .kernel_rpl = 0, 319 .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */ 320}; 321 322struct pv_init_ops pv_init_ops = { 323 .patch = native_patch, 324 .banner = default_banner, 325 .arch_setup = paravirt_nop, 326 .memory_setup = machine_specific_memory_setup, 327}; 328 329struct pv_time_ops pv_time_ops = { 330 .time_init = hpet_time_init, 331 .get_wallclock = native_get_wallclock, 332 .set_wallclock = native_set_wallclock, 333 .sched_clock = native_sched_clock, 334 .get_tsc_khz = native_calibrate_tsc, 335}; 336 337struct pv_irq_ops pv_irq_ops = { 338 .init_IRQ = native_init_IRQ, 339 .save_fl = __PV_IS_CALLEE_SAVE(native_save_fl), 340 .restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl), 341 .irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable), 342 .irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable), 343 .safe_halt = native_safe_halt, 344 .halt = native_halt, 345#ifdef CONFIG_X86_64 346 .adjust_exception_frame = paravirt_nop, 347#endif 348}; 349 350struct pv_cpu_ops pv_cpu_ops = { 351 .cpuid = native_cpuid, 352 .get_debugreg = native_get_debugreg, 353 .set_debugreg = native_set_debugreg, 354 .clts = native_clts, 355 .read_cr0 = native_read_cr0, 356 .write_cr0 = native_write_cr0, 357 .read_cr4 = native_read_cr4, 358 .read_cr4_safe = native_read_cr4_safe, 359 .write_cr4 = native_write_cr4, 360#ifdef CONFIG_X86_64 361 .read_cr8 = native_read_cr8, 362 .write_cr8 = native_write_cr8, 363#endif 364 .wbinvd = native_wbinvd, 365 .read_msr = native_read_msr_safe, 366 .read_msr_amd = native_read_msr_amd_safe, 367 .write_msr = native_write_msr_safe, 368 .read_tsc = native_read_tsc, 369 .read_pmc = native_read_pmc, 370 .read_tscp = native_read_tscp, 371 .load_tr_desc = native_load_tr_desc, 372 .set_ldt = native_set_ldt, 373 .load_gdt = native_load_gdt, 374 .load_idt = native_load_idt, 375 .store_gdt = native_store_gdt, 376 .store_idt = native_store_idt, 377 .store_tr = native_store_tr, 378 .load_tls = native_load_tls, 379#ifdef CONFIG_X86_64 380 .load_gs_index = native_load_gs_index, 381#endif 382 .write_ldt_entry = native_write_ldt_entry, 383 .write_gdt_entry = native_write_gdt_entry, 384 .write_idt_entry = native_write_idt_entry, 385 386 .alloc_ldt = paravirt_nop, 387 .free_ldt = paravirt_nop, 388 389 .load_sp0 = native_load_sp0, 390 391#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION) 392 .irq_enable_sysexit = native_irq_enable_sysexit, 393#endif 394#ifdef CONFIG_X86_64 395#ifdef CONFIG_IA32_EMULATION 396 .usergs_sysret32 = native_usergs_sysret32, 397#endif 398 .usergs_sysret64 = native_usergs_sysret64, 399#endif 400 .iret = native_iret, 401 .swapgs = native_swapgs, 402 403 .set_iopl_mask = native_set_iopl_mask, 404 .io_delay = native_io_delay, 405 406 .lazy_mode = { 407 .enter = paravirt_nop, 408 .leave = paravirt_nop, 409 }, 410}; 411 412struct pv_apic_ops pv_apic_ops = { 413#ifdef CONFIG_X86_LOCAL_APIC 414 .setup_boot_clock = setup_boot_APIC_clock, 415 .setup_secondary_clock = setup_secondary_APIC_clock, 416 .startup_ipi_hook = paravirt_nop, 417#endif 418}; 419 420#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE) 421/* 32-bit pagetable entries */ 422#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_32) 423#else 424/* 64-bit pagetable entries */ 425#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64) 426#endif 427 428struct pv_mmu_ops pv_mmu_ops = { 429#ifndef CONFIG_X86_64 430 .pagetable_setup_start = native_pagetable_setup_start, 431 .pagetable_setup_done = native_pagetable_setup_done, 432#else 433 .pagetable_setup_start = paravirt_nop, 434 .pagetable_setup_done = paravirt_nop, 435#endif 436 437 .read_cr2 = native_read_cr2, 438 .write_cr2 = native_write_cr2, 439 .read_cr3 = native_read_cr3, 440 .write_cr3 = native_write_cr3, 441 442 .flush_tlb_user = native_flush_tlb, 443 .flush_tlb_kernel = native_flush_tlb_global, 444 .flush_tlb_single = native_flush_tlb_single, 445 .flush_tlb_others = native_flush_tlb_others, 446 447 .pgd_alloc = __paravirt_pgd_alloc, 448 .pgd_free = paravirt_nop, 449 450 .alloc_pte = paravirt_nop, 451 .alloc_pmd = paravirt_nop, 452 .alloc_pmd_clone = paravirt_nop, 453 .alloc_pud = paravirt_nop, 454 .release_pte = paravirt_nop, 455 .release_pmd = paravirt_nop, 456 .release_pud = paravirt_nop, 457 458 .set_pte = native_set_pte, 459 .set_pte_at = native_set_pte_at, 460 .set_pmd = native_set_pmd, 461 .pte_update = paravirt_nop, 462 .pte_update_defer = paravirt_nop, 463 464 .ptep_modify_prot_start = __ptep_modify_prot_start, 465 .ptep_modify_prot_commit = __ptep_modify_prot_commit, 466 467#ifdef CONFIG_HIGHPTE 468 .kmap_atomic_pte = kmap_atomic, 469#endif 470 471#if PAGETABLE_LEVELS >= 3 472#ifdef CONFIG_X86_PAE 473 .set_pte_atomic = native_set_pte_atomic, 474 .set_pte_present = native_set_pte_present, 475 .pte_clear = native_pte_clear, 476 .pmd_clear = native_pmd_clear, 477#endif 478 .set_pud = native_set_pud, 479 480 .pmd_val = PTE_IDENT, 481 .make_pmd = PTE_IDENT, 482 483#if PAGETABLE_LEVELS == 4 484 .pud_val = PTE_IDENT, 485 .make_pud = PTE_IDENT, 486 487 .set_pgd = native_set_pgd, 488#endif 489#endif /* PAGETABLE_LEVELS >= 3 */ 490 491 .pte_val = PTE_IDENT, 492 .pgd_val = PTE_IDENT, 493 494 .make_pte = PTE_IDENT, 495 .make_pgd = PTE_IDENT, 496 497 .dup_mmap = paravirt_nop, 498 .exit_mmap = paravirt_nop, 499 .activate_mm = paravirt_nop, 500 501 .lazy_mode = { 502 .enter = paravirt_nop, 503 .leave = paravirt_nop, 504 }, 505 506 .set_fixmap = native_set_fixmap, 507}; 508 509EXPORT_SYMBOL_GPL(pv_time_ops); 510EXPORT_SYMBOL (pv_cpu_ops); 511EXPORT_SYMBOL (pv_mmu_ops); 512EXPORT_SYMBOL_GPL(pv_apic_ops); 513EXPORT_SYMBOL_GPL(pv_info); 514EXPORT_SYMBOL (pv_irq_ops); 515