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901d209a JG |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | ||
b3cf8528 | 3 | #ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG |
57c8a661 | 4 | #include <linux/memblock.h> |
b3cf8528 | 5 | #endif |
38e20b07 | 6 | #include <linux/cpu.h> |
0b34a166 | 7 | #include <linux/kexec.h> |
447ae316 | 8 | #include <linux/slab.h> |
0b34a166 | 9 | |
3cfa210b | 10 | #include <xen/xen.h> |
5ead97c8 JF |
11 | #include <xen/features.h> |
12 | #include <xen/page.h> | |
13 | ||
5ead97c8 JF |
14 | #include <asm/xen/hypercall.h> |
15 | #include <asm/xen/hypervisor.h> | |
a314e3eb | 16 | #include <asm/cpu.h> |
687d77a5 | 17 | #include <asm/e820/api.h> |
73c154c6 | 18 | |
5ead97c8 | 19 | #include "xen-ops.h" |
f447d56d | 20 | #include "smp.h" |
65d0cf0b | 21 | #include "pmu.h" |
5ead97c8 JF |
22 | |
23 | EXPORT_SYMBOL_GPL(hypercall_page); | |
24 | ||
a520996a KRW |
25 | /* |
26 | * Pointer to the xen_vcpu_info structure or | |
27 | * &HYPERVISOR_shared_info->vcpu_info[cpu]. See xen_hvm_init_shared_info | |
28 | * and xen_vcpu_setup for details. By default it points to share_info->vcpu_info | |
29 | * but if the hypervisor supports VCPUOP_register_vcpu_info then it can point | |
30 | * to xen_vcpu_info. The pointer is used in __xen_evtchn_do_upcall to | |
31 | * acknowledge pending events. | |
32 | * Also more subtly it is used by the patched version of irq enable/disable | |
33 | * e.g. xen_irq_enable_direct and xen_iret in PV mode. | |
34 | * | |
35 | * The desire to be able to do those mask/unmask operations as a single | |
36 | * instruction by using the per-cpu offset held in %gs is the real reason | |
37 | * vcpu info is in a per-cpu pointer and the original reason for this | |
38 | * hypercall. | |
39 | * | |
40 | */ | |
5ead97c8 | 41 | DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu); |
a520996a KRW |
42 | |
43 | /* | |
44 | * Per CPU pages used if hypervisor supports VCPUOP_register_vcpu_info | |
45 | * hypercall. This can be used both in PV and PVHVM mode. The structure | |
46 | * overrides the default per_cpu(xen_vcpu, cpu) value. | |
47 | */ | |
5ead97c8 | 48 | DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); |
9f79991d | 49 | |
88e957d6 | 50 | /* Linux <-> Xen vCPU id mapping */ |
55467dea | 51 | DEFINE_PER_CPU(uint32_t, xen_vcpu_id); |
88e957d6 VK |
52 | EXPORT_PER_CPU_SYMBOL(xen_vcpu_id); |
53 | ||
6e833587 JF |
54 | enum xen_domain_type xen_domain_type = XEN_NATIVE; |
55 | EXPORT_SYMBOL_GPL(xen_domain_type); | |
56 | ||
7e77506a IC |
57 | unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; |
58 | EXPORT_SYMBOL(machine_to_phys_mapping); | |
ccbcdf7c JB |
59 | unsigned long machine_to_phys_nr; |
60 | EXPORT_SYMBOL(machine_to_phys_nr); | |
7e77506a | 61 | |
5ead97c8 JF |
62 | struct start_info *xen_start_info; |
63 | EXPORT_SYMBOL_GPL(xen_start_info); | |
64 | ||
a0d695c8 | 65 | struct shared_info xen_dummy_shared_info; |
60223a32 | 66 | |
3dbd8204 BO |
67 | __read_mostly int xen_have_vector_callback; |
68 | EXPORT_SYMBOL_GPL(xen_have_vector_callback); | |
69 | ||
1fe83888 RPM |
70 | /* |
71 | * NB: needs to live in .data because it's used by xen_prepare_pvh which runs | |
72 | * before clearing the bss. | |
73 | */ | |
33def849 | 74 | uint32_t xen_start_flags __section(".data") = 0; |
1fe83888 RPM |
75 | EXPORT_SYMBOL(xen_start_flags); |
76 | ||
60223a32 JF |
77 | /* |
78 | * Point at some empty memory to start with. We map the real shared_info | |
79 | * page as soon as fixmap is up and running. | |
80 | */ | |
4648da7c | 81 | struct shared_info *HYPERVISOR_shared_info = &xen_dummy_shared_info; |
60223a32 JF |
82 | |
83 | /* | |
84 | * Flag to determine whether vcpu info placement is available on all | |
85 | * VCPUs. We assume it is to start with, and then set it to zero on | |
86 | * the first failure. This is because it can succeed on some VCPUs | |
87 | * and not others, since it can involve hypervisor memory allocation, | |
88 | * or because the guest failed to guarantee all the appropriate | |
89 | * constraints on all VCPUs (ie buffer can't cross a page boundary). | |
90 | * | |
91 | * Note that any particular CPU may be using a placed vcpu structure, | |
92 | * but we can only optimise if the all are. | |
93 | * | |
94 | * 0: not available, 1: available | |
95 | */ | |
52519f2a | 96 | int xen_have_vcpu_info_placement = 1; |
60223a32 | 97 | |
e1dab14c VK |
98 | static int xen_cpu_up_online(unsigned int cpu) |
99 | { | |
100 | xen_init_lock_cpu(cpu); | |
101 | return 0; | |
102 | } | |
1c32cdc6 | 103 | |
e1dab14c VK |
104 | int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int), |
105 | int (*cpu_dead_cb)(unsigned int)) | |
106 | { | |
107 | int rc; | |
108 | ||
109 | rc = cpuhp_setup_state_nocalls(CPUHP_XEN_PREPARE, | |
eac779aa | 110 | "x86/xen/guest:prepare", |
e1dab14c VK |
111 | cpu_up_prepare_cb, cpu_dead_cb); |
112 | if (rc >= 0) { | |
113 | rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, | |
eac779aa | 114 | "x86/xen/guest:online", |
e1dab14c VK |
115 | xen_cpu_up_online, NULL); |
116 | if (rc < 0) | |
117 | cpuhp_remove_state_nocalls(CPUHP_XEN_PREPARE); | |
118 | } | |
119 | ||
120 | return rc >= 0 ? 0 : rc; | |
121 | } | |
1c32cdc6 | 122 | |
c9b5d98b | 123 | static int xen_vcpu_setup_restore(int cpu) |
0b64ffb8 | 124 | { |
c9b5d98b AA |
125 | int rc = 0; |
126 | ||
0b64ffb8 AA |
127 | /* Any per_cpu(xen_vcpu) is stale, so reset it */ |
128 | xen_vcpu_info_reset(cpu); | |
129 | ||
130 | /* | |
131 | * For PVH and PVHVM, setup online VCPUs only. The rest will | |
132 | * be handled by hotplug. | |
133 | */ | |
134 | if (xen_pv_domain() || | |
135 | (xen_hvm_domain() && cpu_online(cpu))) { | |
c9b5d98b | 136 | rc = xen_vcpu_setup(cpu); |
0b64ffb8 | 137 | } |
c9b5d98b AA |
138 | |
139 | return rc; | |
0b64ffb8 AA |
140 | } |
141 | ||
ad73fd59 AA |
142 | /* |
143 | * On restore, set the vcpu placement up again. | |
144 | * If it fails, then we're in a bad state, since | |
145 | * we can't back out from using it... | |
146 | */ | |
147 | void xen_vcpu_restore(void) | |
148 | { | |
c9b5d98b | 149 | int cpu, rc; |
ad73fd59 AA |
150 | |
151 | for_each_possible_cpu(cpu) { | |
152 | bool other_cpu = (cpu != smp_processor_id()); | |
0b64ffb8 AA |
153 | bool is_up; |
154 | ||
155 | if (xen_vcpu_nr(cpu) == XEN_VCPU_ID_INVALID) | |
156 | continue; | |
157 | ||
158 | /* Only Xen 4.5 and higher support this. */ | |
159 | is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, | |
160 | xen_vcpu_nr(cpu), NULL) > 0; | |
ad73fd59 AA |
161 | |
162 | if (other_cpu && is_up && | |
163 | HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL)) | |
164 | BUG(); | |
165 | ||
0b64ffb8 AA |
166 | if (xen_pv_domain() || xen_feature(XENFEAT_hvm_safe_pvclock)) |
167 | xen_setup_runstate_info(cpu); | |
ad73fd59 | 168 | |
c9b5d98b AA |
169 | rc = xen_vcpu_setup_restore(cpu); |
170 | if (rc) | |
171 | pr_emerg_once("vcpu restore failed for cpu=%d err=%d. " | |
172 | "System will hang.\n", cpu, rc); | |
173 | /* | |
174 | * In case xen_vcpu_setup_restore() fails, do not bring up the | |
175 | * VCPU. This helps us avoid the resulting OOPS when the VCPU | |
176 | * accesses pvclock_vcpu_time via xen_vcpu (which is NULL.) | |
177 | * Note that this does not improve the situation much -- now the | |
178 | * VM hangs instead of OOPSing -- with the VCPUs that did not | |
179 | * fail, spinning in stop_machine(), waiting for the failed | |
180 | * VCPUs to come up. | |
181 | */ | |
182 | if (other_cpu && is_up && (rc == 0) && | |
ad73fd59 AA |
183 | HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL)) |
184 | BUG(); | |
185 | } | |
186 | } | |
187 | ||
ad73fd59 AA |
188 | void xen_vcpu_info_reset(int cpu) |
189 | { | |
190 | if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) { | |
191 | per_cpu(xen_vcpu, cpu) = | |
192 | &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)]; | |
193 | } else { | |
194 | /* Set to NULL so that if somebody accesses it we get an OOPS */ | |
195 | per_cpu(xen_vcpu, cpu) = NULL; | |
196 | } | |
197 | } | |
198 | ||
c9b5d98b | 199 | int xen_vcpu_setup(int cpu) |
5ead97c8 | 200 | { |
60223a32 JF |
201 | struct vcpu_register_vcpu_info info; |
202 | int err; | |
203 | struct vcpu_info *vcpup; | |
204 | ||
a0d695c8 | 205 | BUG_ON(HYPERVISOR_shared_info == &xen_dummy_shared_info); |
60223a32 | 206 | |
7f1fc268 | 207 | /* |
0b64ffb8 AA |
208 | * This path is called on PVHVM at bootup (xen_hvm_smp_prepare_boot_cpu) |
209 | * and at restore (xen_vcpu_restore). Also called for hotplugged | |
210 | * VCPUs (cpu_init -> xen_hvm_cpu_prepare_hvm). | |
211 | * However, the hypercall can only be done once (see below) so if a VCPU | |
212 | * is offlined and comes back online then let's not redo the hypercall. | |
7f1fc268 KRW |
213 | * |
214 | * For PV it is called during restore (xen_vcpu_restore) and bootup | |
215 | * (xen_setup_vcpu_info_placement). The hotplug mechanism does not | |
216 | * use this function. | |
217 | */ | |
218 | if (xen_hvm_domain()) { | |
219 | if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu)) | |
c9b5d98b | 220 | return 0; |
7f1fc268 | 221 | } |
ad73fd59 | 222 | |
ad73fd59 AA |
223 | if (xen_have_vcpu_info_placement) { |
224 | vcpup = &per_cpu(xen_vcpu_info, cpu); | |
225 | info.mfn = arbitrary_virt_to_mfn(vcpup); | |
226 | info.offset = offset_in_page(vcpup); | |
227 | ||
228 | /* | |
229 | * Check to see if the hypervisor will put the vcpu_info | |
230 | * structure where we want it, which allows direct access via | |
231 | * a percpu-variable. | |
232 | * N.B. This hypercall can _only_ be called once per CPU. | |
233 | * Subsequent calls will error out with -EINVAL. This is due to | |
234 | * the fact that hypervisor has no unregister variant and this | |
235 | * hypercall does not allow to over-write info.mfn and | |
236 | * info.offset. | |
237 | */ | |
238 | err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, | |
239 | xen_vcpu_nr(cpu), &info); | |
240 | ||
241 | if (err) { | |
242 | pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n", | |
243 | cpu, err); | |
244 | xen_have_vcpu_info_placement = 0; | |
245 | } else { | |
246 | /* | |
247 | * This cpu is using the registered vcpu info, even if | |
248 | * later ones fail to. | |
249 | */ | |
250 | per_cpu(xen_vcpu, cpu) = vcpup; | |
251 | } | |
252 | } | |
60223a32 | 253 | |
c9b5d98b | 254 | if (!xen_have_vcpu_info_placement) |
0b64ffb8 | 255 | xen_vcpu_info_reset(cpu); |
c9b5d98b AA |
256 | |
257 | return ((per_cpu(xen_vcpu, cpu) == NULL) ? -ENODEV : 0); | |
5ead97c8 JF |
258 | } |
259 | ||
e1dab14c | 260 | void xen_reboot(int reason) |
9c7a7942 | 261 | { |
e1dab14c | 262 | struct sched_shutdown r = { .reason = reason }; |
3905bb2a | 263 | int cpu; |
9c7a7942 | 264 | |
e1dab14c VK |
265 | for_each_online_cpu(cpu) |
266 | xen_pmu_finish(cpu); | |
aa1acff3 | 267 | |
e1dab14c | 268 | if (HYPERVISOR_sched_op(SCHEDOP_shutdown, &r)) |
a05d2eba | 269 | BUG(); |
38ffbe66 JF |
270 | } |
271 | ||
c6875f3a BO |
272 | static int reboot_reason = SHUTDOWN_reboot; |
273 | static bool xen_legacy_crash; | |
e1dab14c | 274 | void xen_emergency_restart(void) |
5ead97c8 | 275 | { |
c6875f3a | 276 | xen_reboot(reboot_reason); |
5ead97c8 JF |
277 | } |
278 | ||
e1dab14c VK |
279 | static int |
280 | xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) | |
5ead97c8 | 281 | { |
c6875f3a BO |
282 | if (!kexec_crash_loaded()) { |
283 | if (xen_legacy_crash) | |
284 | xen_reboot(SHUTDOWN_crash); | |
285 | ||
286 | reboot_reason = SHUTDOWN_crash; | |
287 | ||
288 | /* | |
289 | * If panic_timeout==0 then we are supposed to wait forever. | |
290 | * However, to preserve original dom0 behavior we have to drop | |
291 | * into hypervisor. (domU behavior is controlled by its | |
292 | * config file) | |
293 | */ | |
294 | if (panic_timeout == 0) | |
295 | panic_timeout = -1; | |
296 | } | |
e1dab14c | 297 | return NOTIFY_DONE; |
5ead97c8 JF |
298 | } |
299 | ||
c6875f3a BO |
300 | static int __init parse_xen_legacy_crash(char *arg) |
301 | { | |
302 | xen_legacy_crash = true; | |
303 | return 0; | |
304 | } | |
305 | early_param("xen_legacy_crash", parse_xen_legacy_crash); | |
306 | ||
e1dab14c VK |
307 | static struct notifier_block xen_panic_block = { |
308 | .notifier_call = xen_panic_event, | |
309 | .priority = INT_MIN | |
310 | }; | |
577eebea | 311 | |
e1dab14c | 312 | int xen_panic_handler_init(void) |
59290362 | 313 | { |
e1dab14c VK |
314 | atomic_notifier_chain_register(&panic_notifier_list, &xen_panic_block); |
315 | return 0; | |
59290362 DV |
316 | } |
317 | ||
e1dab14c | 318 | void xen_pin_vcpu(int cpu) |
5ead97c8 | 319 | { |
e1dab14c VK |
320 | static bool disable_pinning; |
321 | struct sched_pin_override pin_override; | |
322 | int ret; | |
1c32cdc6 | 323 | |
e1dab14c | 324 | if (disable_pinning) |
1c32cdc6 DV |
325 | return; |
326 | ||
e1dab14c VK |
327 | pin_override.pcpu = cpu; |
328 | ret = HYPERVISOR_sched_op(SCHEDOP_pin_override, &pin_override); | |
5ead97c8 | 329 | |
e1dab14c VK |
330 | /* Ignore errors when removing override. */ |
331 | if (cpu < 0) | |
332 | return; | |
5ead97c8 | 333 | |
e1dab14c VK |
334 | switch (ret) { |
335 | case -ENOSYS: | |
336 | pr_warn("Unable to pin on physical cpu %d. In case of problems consider vcpu pinning.\n", | |
337 | cpu); | |
338 | disable_pinning = true; | |
339 | break; | |
340 | case -EPERM: | |
341 | WARN(1, "Trying to pin vcpu without having privilege to do so\n"); | |
342 | disable_pinning = true; | |
343 | break; | |
344 | case -EINVAL: | |
345 | case -EBUSY: | |
346 | pr_warn("Physical cpu %d not available for pinning. Check Xen cpu configuration.\n", | |
347 | cpu); | |
348 | break; | |
349 | case 0: | |
350 | break; | |
351 | default: | |
352 | WARN(1, "rc %d while trying to pin vcpu\n", ret); | |
353 | disable_pinning = true; | |
8a95408e | 354 | } |
5ead97c8 JF |
355 | } |
356 | ||
a314e3eb SS |
357 | #ifdef CONFIG_HOTPLUG_CPU |
358 | void xen_arch_register_cpu(int num) | |
359 | { | |
360 | arch_register_cpu(num); | |
361 | } | |
362 | EXPORT_SYMBOL(xen_arch_register_cpu); | |
363 | ||
364 | void xen_arch_unregister_cpu(int num) | |
365 | { | |
366 | arch_unregister_cpu(num); | |
367 | } | |
368 | EXPORT_SYMBOL(xen_arch_unregister_cpu); | |
369 | #endif |