1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Paravirtualization interfaces
3 Copyright (C) 2006 Rusty Russell IBM Corporation
4
5
6 2007 - x86_64 support added by Glauber de Oliveira Costa, Red Hat Inc
7 */
8
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 #include <linux/pgtable.h>
17 #include <linux/static_call.h>
18
19 #include <asm/bug.h>
20 #include <asm/paravirt.h>
21 #include <asm/debugreg.h>
22 #include <asm/desc.h>
23 #include <asm/setup.h>
24 #include <asm/time.h>
25 #include <asm/pgalloc.h>
26 #include <asm/irq.h>
27 #include <asm/delay.h>
28 #include <asm/fixmap.h>
29 #include <asm/apic.h>
30 #include <asm/tlbflush.h>
31 #include <asm/timer.h>
32 #include <asm/special_insns.h>
33 #include <asm/tlb.h>
34 #include <asm/io_bitmap.h>
35 #include <asm/gsseg.h>
36
37 /* stub always returning 0. */
38 DEFINE_ASM_FUNC(paravirt_ret0, "xor %eax,%eax", .entry.text);
39
default_banner(void)40 void __init default_banner(void)
41 {
42 printk(KERN_INFO "Booting paravirtualized kernel on %s\n",
43 pv_info.name);
44 }
45
46 #ifdef CONFIG_PARAVIRT_XXL
47 DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text);
48 DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text);
49 DEFINE_ASM_FUNC(pv_native_irq_disable, "cli", .noinstr.text);
50 DEFINE_ASM_FUNC(pv_native_irq_enable, "sti", .noinstr.text);
51 DEFINE_ASM_FUNC(pv_native_read_cr2, "mov %cr2, %rax", .noinstr.text);
52 #endif
53
54 DEFINE_STATIC_KEY_FALSE(virt_spin_lock_key);
55
native_pv_lock_init(void)56 void __init native_pv_lock_init(void)
57 {
58 if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
59 static_branch_enable(&virt_spin_lock_key);
60 }
61
62 #ifndef CONFIG_PT_RECLAIM
native_tlb_remove_table(struct mmu_gather * tlb,void * table)63 static void native_tlb_remove_table(struct mmu_gather *tlb, void *table)
64 {
65 struct ptdesc *ptdesc = (struct ptdesc *)table;
66
67 pagetable_dtor(ptdesc);
68 tlb_remove_page(tlb, ptdesc_page(ptdesc));
69 }
70 #else
native_tlb_remove_table(struct mmu_gather * tlb,void * table)71 static void native_tlb_remove_table(struct mmu_gather *tlb, void *table)
72 {
73 tlb_remove_table(tlb, table);
74 }
75 #endif
76
77 struct static_key paravirt_steal_enabled;
78 struct static_key paravirt_steal_rq_enabled;
79
native_steal_clock(int cpu)80 static u64 native_steal_clock(int cpu)
81 {
82 return 0;
83 }
84
85 DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
86 DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
87
paravirt_set_sched_clock(u64 (* func)(void))88 void paravirt_set_sched_clock(u64 (*func)(void))
89 {
90 static_call_update(pv_sched_clock, func);
91 }
92
93 /* These are in entry.S */
94 static struct resource reserve_ioports = {
95 .start = 0,
96 .end = IO_SPACE_LIMIT,
97 .name = "paravirt-ioport",
98 .flags = IORESOURCE_IO | IORESOURCE_BUSY,
99 };
100
101 /*
102 * Reserve the whole legacy IO space to prevent any legacy drivers
103 * from wasting time probing for their hardware. This is a fairly
104 * brute-force approach to disabling all non-virtual drivers.
105 *
106 * Note that this must be called very early to have any effect.
107 */
paravirt_disable_iospace(void)108 int paravirt_disable_iospace(void)
109 {
110 return request_resource(&ioport_resource, &reserve_ioports);
111 }
112
pv_native_safe_halt(void)113 static noinstr void pv_native_safe_halt(void)
114 {
115 native_safe_halt();
116 }
117
118 #ifdef CONFIG_PARAVIRT_XXL
pv_native_write_cr2(unsigned long val)119 static noinstr void pv_native_write_cr2(unsigned long val)
120 {
121 native_write_cr2(val);
122 }
123
pv_native_get_debugreg(int regno)124 static noinstr unsigned long pv_native_get_debugreg(int regno)
125 {
126 return native_get_debugreg(regno);
127 }
128
pv_native_set_debugreg(int regno,unsigned long val)129 static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
130 {
131 native_set_debugreg(regno, val);
132 }
133 #endif
134
135 struct pv_info pv_info = {
136 .name = "bare hardware",
137 #ifdef CONFIG_PARAVIRT_XXL
138 .extra_user_64bit_cs = __USER_CS,
139 #endif
140 };
141
142 /* 64-bit pagetable entries */
143 #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
144
145 struct paravirt_patch_template pv_ops = {
146 /* Cpu ops. */
147 .cpu.io_delay = native_io_delay,
148
149 #ifdef CONFIG_PARAVIRT_XXL
150 .cpu.cpuid = native_cpuid,
151 .cpu.get_debugreg = pv_native_get_debugreg,
152 .cpu.set_debugreg = pv_native_set_debugreg,
153 .cpu.read_cr0 = native_read_cr0,
154 .cpu.write_cr0 = native_write_cr0,
155 .cpu.write_cr4 = native_write_cr4,
156 .cpu.read_msr = native_read_msr,
157 .cpu.write_msr = native_write_msr,
158 .cpu.read_msr_safe = native_read_msr_safe,
159 .cpu.write_msr_safe = native_write_msr_safe,
160 .cpu.read_pmc = native_read_pmc,
161 .cpu.load_tr_desc = native_load_tr_desc,
162 .cpu.set_ldt = native_set_ldt,
163 .cpu.load_gdt = native_load_gdt,
164 .cpu.load_idt = native_load_idt,
165 .cpu.store_tr = native_store_tr,
166 .cpu.load_tls = native_load_tls,
167 .cpu.load_gs_index = native_load_gs_index,
168 .cpu.write_ldt_entry = native_write_ldt_entry,
169 .cpu.write_gdt_entry = native_write_gdt_entry,
170 .cpu.write_idt_entry = native_write_idt_entry,
171
172 .cpu.alloc_ldt = paravirt_nop,
173 .cpu.free_ldt = paravirt_nop,
174
175 .cpu.load_sp0 = native_load_sp0,
176
177 #ifdef CONFIG_X86_IOPL_IOPERM
178 .cpu.invalidate_io_bitmap = native_tss_invalidate_io_bitmap,
179 .cpu.update_io_bitmap = native_tss_update_io_bitmap,
180 #endif
181
182 .cpu.start_context_switch = paravirt_nop,
183 .cpu.end_context_switch = paravirt_nop,
184
185 /* Irq ops. */
186 .irq.save_fl = __PV_IS_CALLEE_SAVE(pv_native_save_fl),
187 .irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
188 .irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
189 #endif /* CONFIG_PARAVIRT_XXL */
190
191 /* Irq HLT ops. */
192 .irq.safe_halt = pv_native_safe_halt,
193 .irq.halt = native_halt,
194
195 /* Mmu ops. */
196 .mmu.flush_tlb_user = native_flush_tlb_local,
197 .mmu.flush_tlb_kernel = native_flush_tlb_global,
198 .mmu.flush_tlb_one_user = native_flush_tlb_one_user,
199 .mmu.flush_tlb_multi = native_flush_tlb_multi,
200 .mmu.tlb_remove_table = native_tlb_remove_table,
201
202 .mmu.exit_mmap = paravirt_nop,
203 .mmu.notify_page_enc_status_changed = paravirt_nop,
204
205 #ifdef CONFIG_PARAVIRT_XXL
206 .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
207 .mmu.write_cr2 = pv_native_write_cr2,
208 .mmu.read_cr3 = __native_read_cr3,
209 .mmu.write_cr3 = native_write_cr3,
210
211 .mmu.pgd_alloc = __paravirt_pgd_alloc,
212 .mmu.pgd_free = paravirt_nop,
213
214 .mmu.alloc_pte = paravirt_nop,
215 .mmu.alloc_pmd = paravirt_nop,
216 .mmu.alloc_pud = paravirt_nop,
217 .mmu.alloc_p4d = paravirt_nop,
218 .mmu.release_pte = paravirt_nop,
219 .mmu.release_pmd = paravirt_nop,
220 .mmu.release_pud = paravirt_nop,
221 .mmu.release_p4d = paravirt_nop,
222
223 .mmu.set_pte = native_set_pte,
224 .mmu.set_pmd = native_set_pmd,
225
226 .mmu.ptep_modify_prot_start = __ptep_modify_prot_start,
227 .mmu.ptep_modify_prot_commit = __ptep_modify_prot_commit,
228
229 .mmu.set_pud = native_set_pud,
230
231 .mmu.pmd_val = PTE_IDENT,
232 .mmu.make_pmd = PTE_IDENT,
233
234 .mmu.pud_val = PTE_IDENT,
235 .mmu.make_pud = PTE_IDENT,
236
237 .mmu.set_p4d = native_set_p4d,
238
239 #if CONFIG_PGTABLE_LEVELS >= 5
240 .mmu.p4d_val = PTE_IDENT,
241 .mmu.make_p4d = PTE_IDENT,
242
243 .mmu.set_pgd = native_set_pgd,
244 #endif /* CONFIG_PGTABLE_LEVELS >= 5 */
245
246 .mmu.pte_val = PTE_IDENT,
247 .mmu.pgd_val = PTE_IDENT,
248
249 .mmu.make_pte = PTE_IDENT,
250 .mmu.make_pgd = PTE_IDENT,
251
252 .mmu.enter_mmap = paravirt_nop,
253
254 .mmu.lazy_mode = {
255 .enter = paravirt_nop,
256 .leave = paravirt_nop,
257 .flush = paravirt_nop,
258 },
259
260 .mmu.set_fixmap = native_set_fixmap,
261 #endif /* CONFIG_PARAVIRT_XXL */
262
263 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
264 /* Lock ops. */
265 #ifdef CONFIG_SMP
266 .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
267 .lock.queued_spin_unlock =
268 PV_CALLEE_SAVE(__native_queued_spin_unlock),
269 .lock.wait = paravirt_nop,
270 .lock.kick = paravirt_nop,
271 .lock.vcpu_is_preempted =
272 PV_CALLEE_SAVE(__native_vcpu_is_preempted),
273 #endif /* SMP */
274 #endif
275 };
276
277 #ifdef CONFIG_PARAVIRT_XXL
278 NOKPROBE_SYMBOL(native_load_idt);
279 #endif
280
281 EXPORT_SYMBOL(pv_ops);
282 EXPORT_SYMBOL_GPL(pv_info);
283