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