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
native_tlb_remove_table(struct mmu_gather * tlb,void * table)62 static void native_tlb_remove_table(struct mmu_gather *tlb, void *table)
63 {
64 tlb_remove_page(tlb, table);
65 }
66
67 struct static_key paravirt_steal_enabled;
68 struct static_key paravirt_steal_rq_enabled;
69
native_steal_clock(int cpu)70 static u64 native_steal_clock(int cpu)
71 {
72 return 0;
73 }
74
75 DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
76 DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
77
paravirt_set_sched_clock(u64 (* func)(void))78 void paravirt_set_sched_clock(u64 (*func)(void))
79 {
80 static_call_update(pv_sched_clock, func);
81 }
82
83 /* These are in entry.S */
84 static struct resource reserve_ioports = {
85 .start = 0,
86 .end = IO_SPACE_LIMIT,
87 .name = "paravirt-ioport",
88 .flags = IORESOURCE_IO | IORESOURCE_BUSY,
89 };
90
91 /*
92 * Reserve the whole legacy IO space to prevent any legacy drivers
93 * from wasting time probing for their hardware. This is a fairly
94 * brute-force approach to disabling all non-virtual drivers.
95 *
96 * Note that this must be called very early to have any effect.
97 */
paravirt_disable_iospace(void)98 int paravirt_disable_iospace(void)
99 {
100 return request_resource(&ioport_resource, &reserve_ioports);
101 }
102
103 #ifdef CONFIG_PARAVIRT_XXL
pv_native_write_cr2(unsigned long val)104 static noinstr void pv_native_write_cr2(unsigned long val)
105 {
106 native_write_cr2(val);
107 }
108
pv_native_get_debugreg(int regno)109 static noinstr unsigned long pv_native_get_debugreg(int regno)
110 {
111 return native_get_debugreg(regno);
112 }
113
pv_native_set_debugreg(int regno,unsigned long val)114 static noinstr void pv_native_set_debugreg(int regno, unsigned long val)
115 {
116 native_set_debugreg(regno, val);
117 }
118
pv_native_wbinvd(void)119 noinstr void pv_native_wbinvd(void)
120 {
121 native_wbinvd();
122 }
123
pv_native_safe_halt(void)124 static noinstr void pv_native_safe_halt(void)
125 {
126 native_safe_halt();
127 }
128 #endif
129
130 struct pv_info pv_info = {
131 .name = "bare hardware",
132 #ifdef CONFIG_PARAVIRT_XXL
133 .extra_user_64bit_cs = __USER_CS,
134 #endif
135 };
136
137 /* 64-bit pagetable entries */
138 #define PTE_IDENT __PV_IS_CALLEE_SAVE(_paravirt_ident_64)
139
140 struct paravirt_patch_template pv_ops = {
141 /* Cpu ops. */
142 .cpu.io_delay = native_io_delay,
143
144 #ifdef CONFIG_PARAVIRT_XXL
145 .cpu.cpuid = native_cpuid,
146 .cpu.get_debugreg = pv_native_get_debugreg,
147 .cpu.set_debugreg = pv_native_set_debugreg,
148 .cpu.read_cr0 = native_read_cr0,
149 .cpu.write_cr0 = native_write_cr0,
150 .cpu.write_cr4 = native_write_cr4,
151 .cpu.wbinvd = pv_native_wbinvd,
152 .cpu.read_msr = native_read_msr,
153 .cpu.write_msr = native_write_msr,
154 .cpu.read_msr_safe = native_read_msr_safe,
155 .cpu.write_msr_safe = native_write_msr_safe,
156 .cpu.read_pmc = native_read_pmc,
157 .cpu.load_tr_desc = native_load_tr_desc,
158 .cpu.set_ldt = native_set_ldt,
159 .cpu.load_gdt = native_load_gdt,
160 .cpu.load_idt = native_load_idt,
161 .cpu.store_tr = native_store_tr,
162 .cpu.load_tls = native_load_tls,
163 .cpu.load_gs_index = native_load_gs_index,
164 .cpu.write_ldt_entry = native_write_ldt_entry,
165 .cpu.write_gdt_entry = native_write_gdt_entry,
166 .cpu.write_idt_entry = native_write_idt_entry,
167
168 .cpu.alloc_ldt = paravirt_nop,
169 .cpu.free_ldt = paravirt_nop,
170
171 .cpu.load_sp0 = native_load_sp0,
172
173 #ifdef CONFIG_X86_IOPL_IOPERM
174 .cpu.invalidate_io_bitmap = native_tss_invalidate_io_bitmap,
175 .cpu.update_io_bitmap = native_tss_update_io_bitmap,
176 #endif
177
178 .cpu.start_context_switch = paravirt_nop,
179 .cpu.end_context_switch = paravirt_nop,
180
181 /* Irq ops. */
182 .irq.save_fl = __PV_IS_CALLEE_SAVE(pv_native_save_fl),
183 .irq.irq_disable = __PV_IS_CALLEE_SAVE(pv_native_irq_disable),
184 .irq.irq_enable = __PV_IS_CALLEE_SAVE(pv_native_irq_enable),
185 .irq.safe_halt = pv_native_safe_halt,
186 .irq.halt = native_halt,
187 #endif /* CONFIG_PARAVIRT_XXL */
188
189 /* Mmu ops. */
190 .mmu.flush_tlb_user = native_flush_tlb_local,
191 .mmu.flush_tlb_kernel = native_flush_tlb_global,
192 .mmu.flush_tlb_one_user = native_flush_tlb_one_user,
193 .mmu.flush_tlb_multi = native_flush_tlb_multi,
194 .mmu.tlb_remove_table = native_tlb_remove_table,
195
196 .mmu.exit_mmap = paravirt_nop,
197 .mmu.notify_page_enc_status_changed = paravirt_nop,
198
199 #ifdef CONFIG_PARAVIRT_XXL
200 .mmu.read_cr2 = __PV_IS_CALLEE_SAVE(pv_native_read_cr2),
201 .mmu.write_cr2 = pv_native_write_cr2,
202 .mmu.read_cr3 = __native_read_cr3,
203 .mmu.write_cr3 = native_write_cr3,
204
205 .mmu.pgd_alloc = __paravirt_pgd_alloc,
206 .mmu.pgd_free = paravirt_nop,
207
208 .mmu.alloc_pte = paravirt_nop,
209 .mmu.alloc_pmd = paravirt_nop,
210 .mmu.alloc_pud = paravirt_nop,
211 .mmu.alloc_p4d = paravirt_nop,
212 .mmu.release_pte = paravirt_nop,
213 .mmu.release_pmd = paravirt_nop,
214 .mmu.release_pud = paravirt_nop,
215 .mmu.release_p4d = paravirt_nop,
216
217 .mmu.set_pte = native_set_pte,
218 .mmu.set_pmd = native_set_pmd,
219
220 .mmu.ptep_modify_prot_start = __ptep_modify_prot_start,
221 .mmu.ptep_modify_prot_commit = __ptep_modify_prot_commit,
222
223 .mmu.set_pud = native_set_pud,
224
225 .mmu.pmd_val = PTE_IDENT,
226 .mmu.make_pmd = PTE_IDENT,
227
228 .mmu.pud_val = PTE_IDENT,
229 .mmu.make_pud = PTE_IDENT,
230
231 .mmu.set_p4d = native_set_p4d,
232
233 #if CONFIG_PGTABLE_LEVELS >= 5
234 .mmu.p4d_val = PTE_IDENT,
235 .mmu.make_p4d = PTE_IDENT,
236
237 .mmu.set_pgd = native_set_pgd,
238 #endif /* CONFIG_PGTABLE_LEVELS >= 5 */
239
240 .mmu.pte_val = PTE_IDENT,
241 .mmu.pgd_val = PTE_IDENT,
242
243 .mmu.make_pte = PTE_IDENT,
244 .mmu.make_pgd = PTE_IDENT,
245
246 .mmu.enter_mmap = paravirt_nop,
247
248 .mmu.lazy_mode = {
249 .enter = paravirt_nop,
250 .leave = paravirt_nop,
251 .flush = paravirt_nop,
252 },
253
254 .mmu.set_fixmap = native_set_fixmap,
255 #endif /* CONFIG_PARAVIRT_XXL */
256
257 #if defined(CONFIG_PARAVIRT_SPINLOCKS)
258 /* Lock ops. */
259 #ifdef CONFIG_SMP
260 .lock.queued_spin_lock_slowpath = native_queued_spin_lock_slowpath,
261 .lock.queued_spin_unlock =
262 PV_CALLEE_SAVE(__native_queued_spin_unlock),
263 .lock.wait = paravirt_nop,
264 .lock.kick = paravirt_nop,
265 .lock.vcpu_is_preempted =
266 PV_CALLEE_SAVE(__native_vcpu_is_preempted),
267 #endif /* SMP */
268 #endif
269 };
270
271 #ifdef CONFIG_PARAVIRT_XXL
272 NOKPROBE_SYMBOL(native_load_idt);
273 #endif
274
275 EXPORT_SYMBOL(pv_ops);
276 EXPORT_SYMBOL_GPL(pv_info);
277