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

source code of linux/arch/x86/kernel/paravirt.c