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9#include <linux/errno.h>
10#include <linux/init.h>
11#include <linux/export.h>
12#include <linux/efi.h>
13#include <linux/bcd.h>
14#include <linux/highmem.h>
15#include <linux/kprobes.h>
16
17#include <asm/bug.h>
18#include <asm/paravirt.h>
19#include <asm/debugreg.h>
20#include <asm/desc.h>
21#include <asm/setup.h>
22#include <asm/pgtable.h>
23#include <asm/time.h>
24#include <asm/pgalloc.h>
25#include <asm/irq.h>
26#include <asm/delay.h>
27#include <asm/fixmap.h>
28#include <asm/apic.h>
29#include <asm/tlbflush.h>
30#include <asm/timer.h>
31#include <asm/special_insns.h>
32#include <asm/tlb.h>
33
34
35
36
37
38extern void _paravirt_nop(void);
39asm (".pushsection .entry.text, \"ax\"\n"
40 ".global _paravirt_nop\n"
41 "_paravirt_nop:\n\t"
42 "ret\n\t"
43 ".size _paravirt_nop, . - _paravirt_nop\n\t"
44 ".type _paravirt_nop, @function\n\t"
45 ".popsection");
46
47void __init default_banner(void)
48{
49 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
50 pv_info.name);
51}
52
53
54static const unsigned char ud2a[] = { 0x0f, 0x0b };
55
56struct branch {
57 unsigned char opcode;
58 u32 delta;
59} __attribute__((packed));
60
61static unsigned paravirt_patch_call(void *insn_buff, const void *target,
62 unsigned long addr, unsigned len)
63{
64 const int call_len = 5;
65 struct branch *b = insn_buff;
66 unsigned long delta = (unsigned long)target - (addr+call_len);
67
68 if (len < call_len) {
69 pr_warn("paravirt: Failed to patch indirect CALL at %ps\n", (void *)addr);
70
71 BUG_ON(1);
72 }
73
74 b->opcode = 0xe8;
75 b->delta = delta;
76 BUILD_BUG_ON(sizeof(*b) != call_len);
77
78 return call_len;
79}
80
81#ifdef CONFIG_PARAVIRT_XXL
82
83u64 notrace _paravirt_ident_64(u64 x)
84{
85 return x;
86}
87
88static unsigned paravirt_patch_jmp(void *insn_buff, const void *target,
89 unsigned long addr, unsigned len)
90{
91 struct branch *b = insn_buff;
92 unsigned long delta = (unsigned long)target - (addr+5);
93
94 if (len < 5) {
95#ifdef CONFIG_RETPOLINE
96 WARN_ONCE(1, "Failing to patch indirect JMP in %ps\n", (void *)addr);
97#endif
98 return len;
99 }
100
101 b->opcode = 0xe9;
102 b->delta = delta;
103
104 return 5;
105}
106#endif
107
108DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key);
109
110void __init native_pv_lock_init(void)
111{
112 if (!boot_cpu_has(X86_FEATURE_HYPERVISOR))
113 static_branch_disable(&virt_spin_lock_key);
114}
115
116unsigned paravirt_patch_default(u8 type, void *insn_buff,
117 unsigned long addr, unsigned len)
118{
119
120
121
122
123 void *opfunc = *((void **)&pv_ops + type);
124 unsigned ret;
125
126 if (opfunc == NULL)
127
128 ret = paravirt_patch_insns(insn_buff, len, ud2a, ud2a+sizeof(ud2a));
129 else if (opfunc == _paravirt_nop)
130 ret = 0;
131
132#ifdef CONFIG_PARAVIRT_XXL
133
134 else if (opfunc == _paravirt_ident_64)
135 ret = paravirt_patch_ident_64(insn_buff, len);
136
137 else if (type == PARAVIRT_PATCH(cpu.iret) ||
138 type == PARAVIRT_PATCH(cpu.usergs_sysret64))
139
140 ret = paravirt_patch_jmp(insn_buff, opfunc, addr, len);
141#endif
142 else
143
144 ret = paravirt_patch_call(insn_buff, opfunc, addr, len);
145
146 return ret;
147}
148
149unsigned paravirt_patch_insns(void *insn_buff, unsigned len,
150 const char *start, const char *end)
151{
152 unsigned insn_len = end - start;
153
154
155 BUG_ON(insn_len > len || start == NULL);
156
157 memcpy(insn_buff, start, insn_len);
158
159 return insn_len;
160}
161
162static void native_flush_tlb(void)
163{
164 __native_flush_tlb();
165}
166
167
168
169
170
171static void native_flush_tlb_global(void)
172{
173 __native_flush_tlb_global();
174}
175
176static void native_flush_tlb_one_user(unsigned long addr)
177{
178 __native_flush_tlb_one_user(addr);
179}
180
181struct static_key paravirt_steal_enabled;
182struct static_key paravirt_steal_rq_enabled;
183
184static u64 native_steal_clock(int cpu)
185{
186 return 0;
187}
188
189
190extern void native_iret(void);
191extern void native_usergs_sysret64(void);
192
193static struct resource reserve_ioports = {
194 .start = 0,
195 .end = IO_SPACE_LIMIT,
196 .name = "paravirt-ioport",
197 .flags = IORESOURCE_IO | IORESOURCE_BUSY,
198};
199
200
201
202
203
204
205
206
207int paravirt_disable_iospace(void)
208{
209 return request_resource(&ioport_resource, &reserve_ioports);
210}
211
212static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE;
213
214static inline void enter_lazy(enum paravirt_lazy_mode mode)
215{
216 BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE);
217
218 this_cpu_write(paravirt_lazy_mode, mode);
219}
220
221static void leave_lazy(enum paravirt_lazy_mode mode)
222{
223 BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode);
224
225 this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE);
226}
227
228void paravirt_enter_lazy_mmu(void)
229{
230 enter_lazy(PARAVIRT_LAZY_MMU);
231}
232
233void paravirt_leave_lazy_mmu(void)
234{
235 leave_lazy(PARAVIRT_LAZY_MMU);
236}
237
238void paravirt_flush_lazy_mmu(void)
239{
240 preempt_disable();
241
242 if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) {
243 arch_leave_lazy_mmu_mode();
244 arch_enter_lazy_mmu_mode();
245 }
246
247 preempt_enable();
248}
249
250#ifdef CONFIG_PARAVIRT_XXL
251void paravirt_start_context_switch(struct task_struct *prev)
252{
253 BUG_ON(preemptible());
254
255 if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) {
256 arch_leave_lazy_mmu_mode();
257 set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES);
258 }
259 enter_lazy(PARAVIRT_LAZY_CPU);
260}
261
262void paravirt_end_context_switch(struct task_struct *next)
263{
264 BUG_ON(preemptible());
265
266 leave_lazy(PARAVIRT_LAZY_CPU);
267
268 if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES))
269 arch_enter_lazy_mmu_mode();
270}
271#endif
272
273enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
274{
275 if (in_interrupt())
276 return PARAVIRT_LAZY_NONE;
277
278 return this_cpu_read(paravirt_lazy_mode);
279}
280
281struct pv_info pv_info = {
282 .name = "bare hardware",
283#ifdef CONFIG_PARAVIRT_XXL
284 .kernel_rpl = 0,
285 .shared_kernel_pmd = 1,
286
287#ifdef CONFIG_X86_64
288 .extra_user_64bit_cs = __USER_CS,
289#endif
290#endif
291};
292
293
294#define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
295
296struct paravirt_patch_template pv_ops = {
297
298 .init.patch = native_patch,
299
300
301 .time.sched_clock = native_sched_clock,
302 .time.steal_clock = native_steal_clock,
303
304
305 .cpu.io_delay = native_io_delay,
306
307#ifdef CONFIG_PARAVIRT_XXL
308 .cpu.cpuid = native_cpuid,
309 .cpu.get_debugreg = native_get_debugreg,
310 .cpu.set_debugreg = native_set_debugreg,
311 .cpu.read_cr0 = native_read_cr0,
312 .cpu.write_cr0 = native_write_cr0,
313 .cpu.write_cr4 = native_write_cr4,
314 .cpu.wbinvd = native_wbinvd,
315 .cpu.read_msr = native_read_msr,
316 .cpu.write_msr = native_write_msr,
317 .cpu.read_msr_safe = native_read_msr_safe,
318 .cpu.write_msr_safe = native_write_msr_safe,
319 .cpu.read_pmc = native_read_pmc,
320 .cpu.load_tr_desc = native_load_tr_desc,
321 .cpu.set_ldt = native_set_ldt,
322 .cpu.load_gdt = native_load_gdt,
323 .cpu.load_idt = native_load_idt,
324 .cpu.store_tr = native_store_tr,
325 .cpu.load_tls = native_load_tls,
326#ifdef CONFIG_X86_64
327 .cpu.load_gs_index = native_load_gs_index,
328#endif
329 .cpu.write_ldt_entry = native_write_ldt_entry,
330 .cpu.write_gdt_entry = native_write_gdt_entry,
331 .cpu.write_idt_entry = native_write_idt_entry,
332
333 .cpu.alloc_ldt = paravirt_nop,
334 .cpu.free_ldt = paravirt_nop,
335
336 .cpu.load_sp0 = native_load_sp0,
337
338#ifdef CONFIG_X86_64
339 .cpu.usergs_sysret64 = native_usergs_sysret64,
340#endif
341 .cpu.iret = native_iret,
342 .cpu.swapgs = native_swapgs,
343
344 .cpu.start_context_switch = paravirt_nop,
345 .cpu.end_context_switch = paravirt_nop,
346
347
348 .irq.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl),
349 .irq.restore_fl = __PV_IS_CALLEE_SAVE(native_restore_fl),
350 .irq.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable),
351 .irq.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable),
352 .irq.safe_halt = native_safe_halt,
353 .irq.halt = native_halt,
354#endif
355
356
357 .mmu.flush_tlb_user = native_flush_tlb,
358 .mmu.flush_tlb_kernel = native_flush_tlb_global,
359 .mmu.flush_tlb_one_user = native_flush_tlb_one_user,
360 .mmu.flush_tlb_others = native_flush_tlb_others,
361 .mmu.tlb_remove_table =
362 (void (*)(struct mmu_gather *, void *))tlb_remove_page,
363
364 .mmu.exit_mmap = paravirt_nop,
365
366#ifdef CONFIG_PARAVIRT_XXL
367 .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2),
368 .mmu.write_cr2 = native_write_cr2,
369 .mmu.read_cr3 = __native_read_cr3,
370 .mmu.write_cr3 = native_write_cr3,
371
372 .mmu.pgd_alloc = __paravirt_pgd_alloc,
373 .mmu.pgd_free = paravirt_nop,
374
375 .mmu.alloc_pte = paravirt_nop,
376 .mmu.alloc_pmd = paravirt_nop,
377 .mmu.alloc_pud = paravirt_nop,
378 .mmu.alloc_p4d = paravirt_nop,
379 .mmu.release_pte = paravirt_nop,
380 .mmu.release_pmd = paravirt_nop,
381 .mmu.release_pud = paravirt_nop,
382 .mmu.release_p4d = paravirt_nop,
383
384 .mmu.set_pte = native_set_pte,
385 .mmu.set_pte_at = native_set_pte_at,
386 .mmu.set_pmd = native_set_pmd,
387
388 .mmu.ptep_modify_prot_start = __ptep_modify_prot_start,
389 .mmu.ptep_modify_prot_commit = __ptep_modify_prot_commit,
390
391#if CONFIG_PGTABLE_LEVELS >= 3
392#ifdef CONFIG_X86_PAE
393 .mmu.set_pte_atomic = native_set_pte_atomic,
394 .mmu.pte_clear = native_pte_clear,
395 .mmu.pmd_clear = native_pmd_clear,
396#endif
397 .mmu.set_pud = native_set_pud,
398
399 .mmu.pmd_val = PTE_IDENT,
400 .mmu.make_pmd = PTE_IDENT,
401
402#if CONFIG_PGTABLE_LEVELS >= 4
403 .mmu.pud_val = PTE_IDENT,
404 .mmu.make_pud = PTE_IDENT,
405
406 .mmu.set_p4d = native_set_p4d,
407
408#if CONFIG_PGTABLE_LEVELS >= 5
409 .mmu.p4d_val = PTE_IDENT,
410 .mmu.make_p4d = PTE_IDENT,
411
412 .mmu.set_pgd = native_set_pgd,
413#endif
414#endif
415#endif
416
417 .mmu.pte_val = PTE_IDENT,
418 .mmu.pgd_val = PTE_IDENT,
419
420 .mmu.make_pte = PTE_IDENT,
421 .mmu.make_pgd = PTE_IDENT,
422
423 .mmu.dup_mmap = paravirt_nop,
424 .mmu.activate_mm = paravirt_nop,
425
426 .mmu.lazy_mode = {
427 .enter = paravirt_nop,
428 .leave = paravirt_nop,
429 .flush = paravirt_nop,
430 },
431
432 .mmu.set_fixmap = native_set_fixmap,
433#endif
434
435#if defined(CONFIG_PARAVIRT_SPINLOCKS)
436
437#ifdef CONFIG_SMP
438 .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
439 .lock.queued_spin_unlock =
440 PV_CALLEE_SAVE(__native_queued_spin_unlock),
441 .lock.wait = paravirt_nop,
442 .lock.kick = paravirt_nop,
443 .lock.vcpu_is_preempted =
444 PV_CALLEE_SAVE(__native_vcpu_is_preempted),
445#endif
446#endif
447};
448
449#ifdef CONFIG_PARAVIRT_XXL
450
451NOKPROBE_SYMBOL(native_get_debugreg);
452NOKPROBE_SYMBOL(native_set_debugreg);
453NOKPROBE_SYMBOL(native_load_idt);
454#endif
455
456EXPORT_SYMBOL(pv_ops);
457EXPORT_SYMBOL_GPL(pv_info);
458