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fd534e9b | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
d3561b7f RR |
2 | /* Paravirtualization interfaces |
3 | Copyright (C) 2006 Rusty Russell IBM Corporation | |
4 | ||
b1df07bd GOC |
5 | |
6 | 2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc | |
d3561b7f | 7 | */ |
b1df07bd | 8 | |
d3561b7f | 9 | #include <linux/errno.h> |
186f4360 PG |
10 | #include <linux/init.h> |
11 | #include <linux/export.h> | |
d3561b7f RR |
12 | #include <linux/efi.h> |
13 | #include <linux/bcd.h> | |
ce6234b5 | 14 | #include <linux/highmem.h> |
376e2424 | 15 | #include <linux/kprobes.h> |
65fddcfc | 16 | #include <linux/pgtable.h> |
a0e2bf7c | 17 | #include <linux/static_call.h> |
d3561b7f RR |
18 | |
19 | #include <asm/bug.h> | |
20 | #include <asm/paravirt.h> | |
50af5ead | 21 | #include <asm/debugreg.h> |
d3561b7f RR |
22 | #include <asm/desc.h> |
23 | #include <asm/setup.h> | |
d3561b7f | 24 | #include <asm/time.h> |
eba0045f | 25 | #include <asm/pgalloc.h> |
d3561b7f RR |
26 | #include <asm/irq.h> |
27 | #include <asm/delay.h> | |
13623d79 RR |
28 | #include <asm/fixmap.h> |
29 | #include <asm/apic.h> | |
da181a8b | 30 | #include <asm/tlbflush.h> |
6cb9a835 | 31 | #include <asm/timer.h> |
f05e798a | 32 | #include <asm/special_insns.h> |
48a8b97c | 33 | #include <asm/tlb.h> |
99bcd4a6 | 34 | #include <asm/io_bitmap.h> |
d3561b7f | 35 | |
fc57a7c6 AL |
36 | /* |
37 | * nop stub, which must not clobber anything *including the stack* to | |
38 | * avoid confusing the entry prologues. | |
39 | */ | |
40 | extern void _paravirt_nop(void); | |
41 | asm (".pushsection .entry.text, \"ax\"\n" | |
42 | ".global _paravirt_nop\n" | |
43 | "_paravirt_nop:\n\t" | |
44 | "ret\n\t" | |
45 | ".size _paravirt_nop, . - _paravirt_nop\n\t" | |
46 | ".type _paravirt_nop, @function\n\t" | |
47 | ".popsection"); | |
d3561b7f | 48 | |
6f30c1ac | 49 | void __init default_banner(void) |
d3561b7f RR |
50 | { |
51 | printk(KERN_INFO "Booting paravirtualized kernel on %s\n", | |
93b1eab3 | 52 | pv_info.name); |
d3561b7f RR |
53 | } |
54 | ||
93b1eab3 | 55 | /* Undefined instruction for dealing with missing ops pointers. */ |
fafe5e74 JG |
56 | static void paravirt_BUG(void) |
57 | { | |
58 | BUG(); | |
59 | } | |
139ec7c4 | 60 | |
19d36ccd AK |
61 | struct branch { |
62 | unsigned char opcode; | |
63 | u32 delta; | |
64 | } __attribute__((packed)); | |
65 | ||
1fc654cf | 66 | static unsigned paravirt_patch_call(void *insn_buff, const void *target, |
abc745f8 | 67 | unsigned long addr, unsigned len) |
63f70270 | 68 | { |
11e86dc7 | 69 | const int call_len = 5; |
1fc654cf | 70 | struct branch *b = insn_buff; |
11e86dc7 | 71 | unsigned long delta = (unsigned long)target - (addr+call_len); |
63f70270 | 72 | |
11e86dc7 IM |
73 | if (len < call_len) { |
74 | pr_warn("paravirt: Failed to patch indirect CALL at %ps\n", (void *)addr); | |
75 | /* Kernel might not be viable if patching fails, bail out: */ | |
76 | BUG_ON(1); | |
5800dc5c | 77 | } |
139ec7c4 | 78 | |
ab144f5e AK |
79 | b->opcode = 0xe8; /* call */ |
80 | b->delta = delta; | |
11e86dc7 | 81 | BUILD_BUG_ON(sizeof(*b) != call_len); |
139ec7c4 | 82 | |
11e86dc7 | 83 | return call_len; |
63f70270 JF |
84 | } |
85 | ||
9bad5658 | 86 | #ifdef CONFIG_PARAVIRT_XXL |
7847c7be JG |
87 | /* identity function, which can be inlined */ |
88 | u64 notrace _paravirt_ident_64(u64 x) | |
89 | { | |
90 | return x; | |
91 | } | |
9bad5658 | 92 | #endif |
63f70270 | 93 | |
9043442b JG |
94 | DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key); |
95 | ||
96 | void __init native_pv_lock_init(void) | |
97 | { | |
67e87d43 | 98 | if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) |
9043442b JG |
99 | static_branch_disable(&virt_spin_lock_key); |
100 | } | |
101 | ||
054ac8ad JG |
102 | unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr, |
103 | unsigned int len) | |
63f70270 | 104 | { |
5c83511b JG |
105 | /* |
106 | * Neat trick to map patch type back to the call within the | |
107 | * corresponding structure. | |
108 | */ | |
109 | void *opfunc = *((void **)&pv_ops + type); | |
63f70270 JF |
110 | unsigned ret; |
111 | ||
112 | if (opfunc == NULL) | |
fafe5e74 JG |
113 | /* If there's no function, patch it with paravirt_BUG() */ |
114 | ret = paravirt_patch_call(insn_buff, paravirt_BUG, addr, len); | |
41edafdb | 115 | else if (opfunc == _paravirt_nop) |
79f1d836 | 116 | ret = 0; |
63f70270 | 117 | else |
abc745f8 | 118 | /* Otherwise call the function. */ |
1fc654cf | 119 | ret = paravirt_patch_call(insn_buff, opfunc, addr, len); |
63f70270 JF |
120 | |
121 | return ret; | |
122 | } | |
123 | ||
c5905afb IM |
124 | struct static_key paravirt_steal_enabled; |
125 | struct static_key paravirt_steal_rq_enabled; | |
3c404b57 GC |
126 | |
127 | static u64 native_steal_clock(int cpu) | |
128 | { | |
129 | return 0; | |
130 | } | |
131 | ||
a0e2bf7c JG |
132 | DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock); |
133 | DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock); | |
134 | ||
135 | void paravirt_set_sched_clock(u64 (*func)(void)) | |
136 | { | |
137 | static_call_update(pv_sched_clock, func); | |
138 | } | |
139 | ||
d3561b7f | 140 | /* These are in entry.S */ |
1a1eecd1 | 141 | extern void native_iret(void); |
d3561b7f | 142 | |
d572929c JF |
143 | static struct resource reserve_ioports = { |
144 | .start = 0, | |
145 | .end = IO_SPACE_LIMIT, | |
146 | .name = "paravirt-ioport", | |
147 | .flags = IORESOURCE_IO | IORESOURCE_BUSY, | |
148 | }; | |
149 | ||
d572929c JF |
150 | /* |
151 | * Reserve the whole legacy IO space to prevent any legacy drivers | |
152 | * from wasting time probing for their hardware. This is a fairly | |
153 | * brute-force approach to disabling all non-virtual drivers. | |
154 | * | |
155 | * Note that this must be called very early to have any effect. | |
156 | */ | |
157 | int paravirt_disable_iospace(void) | |
158 | { | |
f7743fe6 | 159 | return request_resource(&ioport_resource, &reserve_ioports); |
d572929c JF |
160 | } |
161 | ||
8965c1c0 JF |
162 | static DEFINE_PER_CPU(enum paravirt_lazy_mode, paravirt_lazy_mode) = PARAVIRT_LAZY_NONE; |
163 | ||
164 | static inline void enter_lazy(enum paravirt_lazy_mode mode) | |
165 | { | |
c6ae41e7 | 166 | BUG_ON(this_cpu_read(paravirt_lazy_mode) != PARAVIRT_LAZY_NONE); |
8965c1c0 | 167 | |
c6ae41e7 | 168 | this_cpu_write(paravirt_lazy_mode, mode); |
8965c1c0 JF |
169 | } |
170 | ||
b407fc57 | 171 | static void leave_lazy(enum paravirt_lazy_mode mode) |
8965c1c0 | 172 | { |
c6ae41e7 | 173 | BUG_ON(this_cpu_read(paravirt_lazy_mode) != mode); |
8965c1c0 | 174 | |
c6ae41e7 | 175 | this_cpu_write(paravirt_lazy_mode, PARAVIRT_LAZY_NONE); |
8965c1c0 JF |
176 | } |
177 | ||
178 | void paravirt_enter_lazy_mmu(void) | |
179 | { | |
180 | enter_lazy(PARAVIRT_LAZY_MMU); | |
181 | } | |
182 | ||
183 | void paravirt_leave_lazy_mmu(void) | |
184 | { | |
b407fc57 | 185 | leave_lazy(PARAVIRT_LAZY_MMU); |
8965c1c0 JF |
186 | } |
187 | ||
511ba86e BO |
188 | void paravirt_flush_lazy_mmu(void) |
189 | { | |
190 | preempt_disable(); | |
191 | ||
192 | if (paravirt_get_lazy_mode() == PARAVIRT_LAZY_MMU) { | |
193 | arch_leave_lazy_mmu_mode(); | |
194 | arch_enter_lazy_mmu_mode(); | |
195 | } | |
196 | ||
197 | preempt_enable(); | |
198 | } | |
199 | ||
9bad5658 | 200 | #ifdef CONFIG_PARAVIRT_XXL |
224101ed | 201 | void paravirt_start_context_switch(struct task_struct *prev) |
8965c1c0 | 202 | { |
2829b449 JF |
203 | BUG_ON(preemptible()); |
204 | ||
c6ae41e7 | 205 | if (this_cpu_read(paravirt_lazy_mode) == PARAVIRT_LAZY_MMU) { |
b407fc57 | 206 | arch_leave_lazy_mmu_mode(); |
224101ed | 207 | set_ti_thread_flag(task_thread_info(prev), TIF_LAZY_MMU_UPDATES); |
b407fc57 | 208 | } |
8965c1c0 JF |
209 | enter_lazy(PARAVIRT_LAZY_CPU); |
210 | } | |
211 | ||
224101ed | 212 | void paravirt_end_context_switch(struct task_struct *next) |
8965c1c0 | 213 | { |
2829b449 JF |
214 | BUG_ON(preemptible()); |
215 | ||
b407fc57 JF |
216 | leave_lazy(PARAVIRT_LAZY_CPU); |
217 | ||
224101ed | 218 | if (test_and_clear_ti_thread_flag(task_thread_info(next), TIF_LAZY_MMU_UPDATES)) |
b407fc57 | 219 | arch_enter_lazy_mmu_mode(); |
8965c1c0 | 220 | } |
9bad5658 | 221 | #endif |
8965c1c0 JF |
222 | |
223 | enum paravirt_lazy_mode paravirt_get_lazy_mode(void) | |
224 | { | |
b8bcfe99 JF |
225 | if (in_interrupt()) |
226 | return PARAVIRT_LAZY_NONE; | |
227 | ||
c6ae41e7 | 228 | return this_cpu_read(paravirt_lazy_mode); |
8965c1c0 JF |
229 | } |
230 | ||
93b1eab3 | 231 | struct pv_info pv_info = { |
d3561b7f | 232 | .name = "bare hardware", |
40181646 | 233 | #ifdef CONFIG_PARAVIRT_XXL |
318f5a2a AL |
234 | .extra_user_64bit_cs = __USER_CS, |
235 | #endif | |
93b1eab3 | 236 | }; |
d3561b7f | 237 | |
41edafdb | 238 | /* 64-bit pagetable entries */ |
da5de7c2 | 239 | #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64) |
41edafdb | 240 | |
5c83511b | 241 | struct paravirt_patch_template pv_ops = { |
5c83511b | 242 | /* Cpu ops. */ |
9bad5658 | 243 | .cpu.io_delay = native_io_delay, |
da181a8b | 244 | |
9bad5658 | 245 | #ifdef CONFIG_PARAVIRT_XXL |
5c83511b JG |
246 | .cpu.cpuid = native_cpuid, |
247 | .cpu.get_debugreg = native_get_debugreg, | |
248 | .cpu.set_debugreg = native_set_debugreg, | |
249 | .cpu.read_cr0 = native_read_cr0, | |
250 | .cpu.write_cr0 = native_write_cr0, | |
251 | .cpu.write_cr4 = native_write_cr4, | |
5c83511b JG |
252 | .cpu.wbinvd = native_wbinvd, |
253 | .cpu.read_msr = native_read_msr, | |
254 | .cpu.write_msr = native_write_msr, | |
255 | .cpu.read_msr_safe = native_read_msr_safe, | |
256 | .cpu.write_msr_safe = native_write_msr_safe, | |
257 | .cpu.read_pmc = native_read_pmc, | |
258 | .cpu.load_tr_desc = native_load_tr_desc, | |
259 | .cpu.set_ldt = native_set_ldt, | |
260 | .cpu.load_gdt = native_load_gdt, | |
261 | .cpu.load_idt = native_load_idt, | |
262 | .cpu.store_tr = native_store_tr, | |
263 | .cpu.load_tls = native_load_tls, | |
5c83511b | 264 | .cpu.load_gs_index = native_load_gs_index, |
5c83511b JG |
265 | .cpu.write_ldt_entry = native_write_ldt_entry, |
266 | .cpu.write_gdt_entry = native_write_gdt_entry, | |
267 | .cpu.write_idt_entry = native_write_idt_entry, | |
eba0045f | 268 | |
5c83511b JG |
269 | .cpu.alloc_ldt = paravirt_nop, |
270 | .cpu.free_ldt = paravirt_nop, | |
c119ecce | 271 | |
5c83511b | 272 | .cpu.load_sp0 = native_load_sp0, |
3dc494e8 | 273 | |
99bcd4a6 | 274 | #ifdef CONFIG_X86_IOPL_IOPERM |
cadfad87 AL |
275 | .cpu.invalidate_io_bitmap = native_tss_invalidate_io_bitmap, |
276 | .cpu.update_io_bitmap = native_tss_update_io_bitmap, | |
99bcd4a6 JG |
277 | #endif |
278 | ||
5c83511b JG |
279 | .cpu.start_context_switch = paravirt_nop, |
280 | .cpu.end_context_switch = paravirt_nop, | |
281 | ||
282 | /* Irq ops. */ | |
283 | .irq.save_fl = __PV_IS_CALLEE_SAVE(native_save_fl), | |
5c83511b JG |
284 | .irq.irq_disable = __PV_IS_CALLEE_SAVE(native_irq_disable), |
285 | .irq.irq_enable = __PV_IS_CALLEE_SAVE(native_irq_enable), | |
286 | .irq.safe_halt = native_safe_halt, | |
287 | .irq.halt = native_halt, | |
6da63eb2 | 288 | #endif /* CONFIG_PARAVIRT_XXL */ |
5c83511b JG |
289 | |
290 | /* Mmu ops. */ | |
2faf153b | 291 | .mmu.flush_tlb_user = native_flush_tlb_local, |
5c83511b JG |
292 | .mmu.flush_tlb_kernel = native_flush_tlb_global, |
293 | .mmu.flush_tlb_one_user = native_flush_tlb_one_user, | |
4ce94eab | 294 | .mmu.flush_tlb_multi = native_flush_tlb_multi, |
5c83511b JG |
295 | .mmu.tlb_remove_table = |
296 | (void (*)(struct mmu_gather *, void *))tlb_remove_page, | |
297 | ||
fdc0269e JG |
298 | .mmu.exit_mmap = paravirt_nop, |
299 | ||
300 | #ifdef CONFIG_PARAVIRT_XXL | |
55aedddb | 301 | .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(native_read_cr2), |
fdc0269e JG |
302 | .mmu.write_cr2 = native_write_cr2, |
303 | .mmu.read_cr3 = __native_read_cr3, | |
304 | .mmu.write_cr3 = native_write_cr3, | |
305 | ||
5c83511b JG |
306 | .mmu.pgd_alloc = __paravirt_pgd_alloc, |
307 | .mmu.pgd_free = paravirt_nop, | |
308 | ||
309 | .mmu.alloc_pte = paravirt_nop, | |
310 | .mmu.alloc_pmd = paravirt_nop, | |
311 | .mmu.alloc_pud = paravirt_nop, | |
312 | .mmu.alloc_p4d = paravirt_nop, | |
313 | .mmu.release_pte = paravirt_nop, | |
314 | .mmu.release_pmd = paravirt_nop, | |
315 | .mmu.release_pud = paravirt_nop, | |
316 | .mmu.release_p4d = paravirt_nop, | |
317 | ||
318 | .mmu.set_pte = native_set_pte, | |
5c83511b JG |
319 | .mmu.set_pmd = native_set_pmd, |
320 | ||
321 | .mmu.ptep_modify_prot_start = __ptep_modify_prot_start, | |
322 | .mmu.ptep_modify_prot_commit = __ptep_modify_prot_commit, | |
08b882c6 | 323 | |
5c83511b | 324 | .mmu.set_pud = native_set_pud, |
da5de7c2 | 325 | |
5c83511b JG |
326 | .mmu.pmd_val = PTE_IDENT, |
327 | .mmu.make_pmd = PTE_IDENT, | |
f95f2f7b | 328 | |
5c83511b JG |
329 | .mmu.pud_val = PTE_IDENT, |
330 | .mmu.make_pud = PTE_IDENT, | |
da5de7c2 | 331 | |
5c83511b | 332 | .mmu.set_p4d = native_set_p4d, |
f2a6a705 KS |
333 | |
334 | #if CONFIG_PGTABLE_LEVELS >= 5 | |
5c83511b JG |
335 | .mmu.p4d_val = PTE_IDENT, |
336 | .mmu.make_p4d = PTE_IDENT, | |
335437fb | 337 | |
5c83511b | 338 | .mmu.set_pgd = native_set_pgd, |
335437fb | 339 | #endif /* CONFIG_PGTABLE_LEVELS >= 5 */ |
da181a8b | 340 | |
5c83511b JG |
341 | .mmu.pte_val = PTE_IDENT, |
342 | .mmu.pgd_val = PTE_IDENT, | |
3dc494e8 | 343 | |
5c83511b JG |
344 | .mmu.make_pte = PTE_IDENT, |
345 | .mmu.make_pgd = PTE_IDENT, | |
3dc494e8 | 346 | |
5c83511b | 347 | .mmu.dup_mmap = paravirt_nop, |
5c83511b | 348 | .mmu.activate_mm = paravirt_nop, |
8965c1c0 | 349 | |
5c83511b JG |
350 | .mmu.lazy_mode = { |
351 | .enter = paravirt_nop, | |
352 | .leave = paravirt_nop, | |
353 | .flush = paravirt_nop, | |
8965c1c0 | 354 | }, |
aeaaa59c | 355 | |
5c83511b | 356 | .mmu.set_fixmap = native_set_fixmap, |
fdc0269e | 357 | #endif /* CONFIG_PARAVIRT_XXL */ |
5c83511b JG |
358 | |
359 | #if defined(CONFIG_PARAVIRT_SPINLOCKS) | |
360 | /* Lock ops. */ | |
361 | #ifdef CONFIG_SMP | |
362 | .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath, | |
363 | .lock.queued_spin_unlock = | |
364 | PV_CALLEE_SAVE(__native_queued_spin_unlock), | |
365 | .lock.wait = paravirt_nop, | |
366 | .lock.kick = paravirt_nop, | |
367 | .lock.vcpu_is_preempted = | |
368 | PV_CALLEE_SAVE(__native_vcpu_is_preempted), | |
369 | #endif /* SMP */ | |
370 | #endif | |
d3561b7f | 371 | }; |
0dbe5a11 | 372 | |
9bad5658 | 373 | #ifdef CONFIG_PARAVIRT_XXL |
5c83511b JG |
374 | /* At this point, native_get/set_debugreg has real function entries */ |
375 | NOKPROBE_SYMBOL(native_get_debugreg); | |
376 | NOKPROBE_SYMBOL(native_set_debugreg); | |
377 | NOKPROBE_SYMBOL(native_load_idt); | |
ae755b5a JG |
378 | |
379 | void (*paravirt_iret)(void) = native_iret; | |
9bad5658 | 380 | #endif |
5c83511b | 381 | |
8af19095 | 382 | EXPORT_SYMBOL(pv_ops); |
93b1eab3 | 383 | EXPORT_SYMBOL_GPL(pv_info); |