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