1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
4 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
5 */
6
7 #include <linux/bug.h>
8 #include <linux/cpu_pm.h>
9 #include <linux/entry-kvm.h>
10 #include <linux/errno.h>
11 #include <linux/err.h>
12 #include <linux/kvm_host.h>
13 #include <linux/list.h>
14 #include <linux/module.h>
15 #include <linux/vmalloc.h>
16 #include <linux/fs.h>
17 #include <linux/mman.h>
18 #include <linux/sched.h>
19 #include <linux/kmemleak.h>
20 #include <linux/kvm.h>
21 #include <linux/kvm_irqfd.h>
22 #include <linux/irqbypass.h>
23 #include <linux/sched/stat.h>
24 #include <linux/psci.h>
25 #include <trace/events/kvm.h>
26
27 #define CREATE_TRACE_POINTS
28 #include "trace_arm.h"
29
30 #include <linux/uaccess.h>
31 #include <asm/ptrace.h>
32 #include <asm/mman.h>
33 #include <asm/tlbflush.h>
34 #include <asm/cacheflush.h>
35 #include <asm/cpufeature.h>
36 #include <asm/virt.h>
37 #include <asm/kvm_arm.h>
38 #include <asm/kvm_asm.h>
39 #include <asm/kvm_mmu.h>
40 #include <asm/kvm_emulate.h>
41 #include <asm/sections.h>
42
43 #include <kvm/arm_hypercalls.h>
44 #include <kvm/arm_pmu.h>
45 #include <kvm/arm_psci.h>
46
47 static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT;
48 DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
49
50 DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
51
52 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
53 unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
54 DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
55
56 static bool vgic_present;
57
58 static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
59 DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
60
kvm_arch_vcpu_should_kick(struct kvm_vcpu * vcpu)61 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
62 {
63 return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
64 }
65
kvm_arch_hardware_setup(void * opaque)66 int kvm_arch_hardware_setup(void *opaque)
67 {
68 return 0;
69 }
70
kvm_arch_check_processor_compat(void * opaque)71 int kvm_arch_check_processor_compat(void *opaque)
72 {
73 return 0;
74 }
75
kvm_vm_ioctl_enable_cap(struct kvm * kvm,struct kvm_enable_cap * cap)76 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
77 struct kvm_enable_cap *cap)
78 {
79 int r;
80
81 if (cap->flags)
82 return -EINVAL;
83
84 switch (cap->cap) {
85 case KVM_CAP_ARM_NISV_TO_USER:
86 r = 0;
87 set_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
88 &kvm->arch.flags);
89 break;
90 case KVM_CAP_ARM_MTE:
91 mutex_lock(&kvm->lock);
92 if (!system_supports_mte() || kvm->created_vcpus) {
93 r = -EINVAL;
94 } else {
95 r = 0;
96 set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags);
97 }
98 mutex_unlock(&kvm->lock);
99 break;
100 case KVM_CAP_ARM_SYSTEM_SUSPEND:
101 r = 0;
102 set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags);
103 break;
104 default:
105 r = -EINVAL;
106 break;
107 }
108
109 return r;
110 }
111
kvm_arm_default_max_vcpus(void)112 static int kvm_arm_default_max_vcpus(void)
113 {
114 return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
115 }
116
set_default_spectre(struct kvm * kvm)117 static void set_default_spectre(struct kvm *kvm)
118 {
119 /*
120 * The default is to expose CSV2 == 1 if the HW isn't affected.
121 * Although this is a per-CPU feature, we make it global because
122 * asymmetric systems are just a nuisance.
123 *
124 * Userspace can override this as long as it doesn't promise
125 * the impossible.
126 */
127 if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED)
128 kvm->arch.pfr0_csv2 = 1;
129 if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED)
130 kvm->arch.pfr0_csv3 = 1;
131 }
132
133 /**
134 * kvm_arch_init_vm - initializes a VM data structure
135 * @kvm: pointer to the KVM struct
136 */
kvm_arch_init_vm(struct kvm * kvm,unsigned long type)137 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
138 {
139 int ret;
140
141 ret = kvm_arm_setup_stage2(kvm, type);
142 if (ret)
143 return ret;
144
145 ret = kvm_init_stage2_mmu(kvm, &kvm->arch.mmu);
146 if (ret)
147 return ret;
148
149 ret = kvm_share_hyp(kvm, kvm + 1);
150 if (ret)
151 goto out_free_stage2_pgd;
152
153 if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL)) {
154 ret = -ENOMEM;
155 goto out_free_stage2_pgd;
156 }
157 cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask);
158
159 kvm_vgic_early_init(kvm);
160
161 /* The maximum number of VCPUs is limited by the host's GIC model */
162 kvm->max_vcpus = kvm_arm_default_max_vcpus();
163
164 set_default_spectre(kvm);
165 kvm_arm_init_hypercalls(kvm);
166
167 return ret;
168 out_free_stage2_pgd:
169 kvm_free_stage2_pgd(&kvm->arch.mmu);
170 return ret;
171 }
172
kvm_arch_vcpu_fault(struct kvm_vcpu * vcpu,struct vm_fault * vmf)173 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
174 {
175 return VM_FAULT_SIGBUS;
176 }
177
178
179 /**
180 * kvm_arch_destroy_vm - destroy the VM data structure
181 * @kvm: pointer to the KVM struct
182 */
kvm_arch_destroy_vm(struct kvm * kvm)183 void kvm_arch_destroy_vm(struct kvm *kvm)
184 {
185 bitmap_free(kvm->arch.pmu_filter);
186 free_cpumask_var(kvm->arch.supported_cpus);
187
188 kvm_vgic_destroy(kvm);
189
190 kvm_destroy_vcpus(kvm);
191
192 kvm_unshare_hyp(kvm, kvm + 1);
193 }
194
kvm_vm_ioctl_check_extension(struct kvm * kvm,long ext)195 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
196 {
197 int r;
198 switch (ext) {
199 case KVM_CAP_IRQCHIP:
200 r = vgic_present;
201 break;
202 case KVM_CAP_IOEVENTFD:
203 case KVM_CAP_DEVICE_CTRL:
204 case KVM_CAP_USER_MEMORY:
205 case KVM_CAP_SYNC_MMU:
206 case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
207 case KVM_CAP_ONE_REG:
208 case KVM_CAP_ARM_PSCI:
209 case KVM_CAP_ARM_PSCI_0_2:
210 case KVM_CAP_READONLY_MEM:
211 case KVM_CAP_MP_STATE:
212 case KVM_CAP_IMMEDIATE_EXIT:
213 case KVM_CAP_VCPU_EVENTS:
214 case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2:
215 case KVM_CAP_ARM_NISV_TO_USER:
216 case KVM_CAP_ARM_INJECT_EXT_DABT:
217 case KVM_CAP_SET_GUEST_DEBUG:
218 case KVM_CAP_VCPU_ATTRIBUTES:
219 case KVM_CAP_PTP_KVM:
220 case KVM_CAP_ARM_SYSTEM_SUSPEND:
221 r = 1;
222 break;
223 case KVM_CAP_SET_GUEST_DEBUG2:
224 return KVM_GUESTDBG_VALID_MASK;
225 case KVM_CAP_ARM_SET_DEVICE_ADDR:
226 r = 1;
227 break;
228 case KVM_CAP_NR_VCPUS:
229 /*
230 * ARM64 treats KVM_CAP_NR_CPUS differently from all other
231 * architectures, as it does not always bound it to
232 * KVM_CAP_MAX_VCPUS. It should not matter much because
233 * this is just an advisory value.
234 */
235 r = min_t(unsigned int, num_online_cpus(),
236 kvm_arm_default_max_vcpus());
237 break;
238 case KVM_CAP_MAX_VCPUS:
239 case KVM_CAP_MAX_VCPU_ID:
240 if (kvm)
241 r = kvm->max_vcpus;
242 else
243 r = kvm_arm_default_max_vcpus();
244 break;
245 case KVM_CAP_MSI_DEVID:
246 if (!kvm)
247 r = -EINVAL;
248 else
249 r = kvm->arch.vgic.msis_require_devid;
250 break;
251 case KVM_CAP_ARM_USER_IRQ:
252 /*
253 * 1: EL1_VTIMER, EL1_PTIMER, and PMU.
254 * (bump this number if adding more devices)
255 */
256 r = 1;
257 break;
258 case KVM_CAP_ARM_MTE:
259 r = system_supports_mte();
260 break;
261 case KVM_CAP_STEAL_TIME:
262 r = kvm_arm_pvtime_supported();
263 break;
264 case KVM_CAP_ARM_EL1_32BIT:
265 r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);
266 break;
267 case KVM_CAP_GUEST_DEBUG_HW_BPS:
268 r = get_num_brps();
269 break;
270 case KVM_CAP_GUEST_DEBUG_HW_WPS:
271 r = get_num_wrps();
272 break;
273 case KVM_CAP_ARM_PMU_V3:
274 r = kvm_arm_support_pmu_v3();
275 break;
276 case KVM_CAP_ARM_INJECT_SERROR_ESR:
277 r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
278 break;
279 case KVM_CAP_ARM_VM_IPA_SIZE:
280 r = get_kvm_ipa_limit();
281 break;
282 case KVM_CAP_ARM_SVE:
283 r = system_supports_sve();
284 break;
285 case KVM_CAP_ARM_PTRAUTH_ADDRESS:
286 case KVM_CAP_ARM_PTRAUTH_GENERIC:
287 r = system_has_full_ptr_auth();
288 break;
289 default:
290 r = 0;
291 }
292
293 return r;
294 }
295
kvm_arch_dev_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)296 long kvm_arch_dev_ioctl(struct file *filp,
297 unsigned int ioctl, unsigned long arg)
298 {
299 return -EINVAL;
300 }
301
kvm_arch_alloc_vm(void)302 struct kvm *kvm_arch_alloc_vm(void)
303 {
304 size_t sz = sizeof(struct kvm);
305
306 if (!has_vhe())
307 return kzalloc(sz, GFP_KERNEL_ACCOUNT);
308
309 return __vmalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM | __GFP_ZERO);
310 }
311
kvm_arch_vcpu_precreate(struct kvm * kvm,unsigned int id)312 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
313 {
314 if (irqchip_in_kernel(kvm) && vgic_initialized(kvm))
315 return -EBUSY;
316
317 if (id >= kvm->max_vcpus)
318 return -EINVAL;
319
320 return 0;
321 }
322
kvm_arch_vcpu_create(struct kvm_vcpu * vcpu)323 int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
324 {
325 int err;
326
327 /* Force users to call KVM_ARM_VCPU_INIT */
328 vcpu->arch.target = -1;
329 bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
330
331 vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
332
333 /* Set up the timer */
334 kvm_timer_vcpu_init(vcpu);
335
336 kvm_pmu_vcpu_init(vcpu);
337
338 kvm_arm_reset_debug_ptr(vcpu);
339
340 kvm_arm_pvtime_vcpu_init(&vcpu->arch);
341
342 vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;
343
344 err = kvm_vgic_vcpu_init(vcpu);
345 if (err)
346 return err;
347
348 return kvm_share_hyp(vcpu, vcpu + 1);
349 }
350
kvm_arch_vcpu_postcreate(struct kvm_vcpu * vcpu)351 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
352 {
353 }
354
kvm_arch_vcpu_destroy(struct kvm_vcpu * vcpu)355 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
356 {
357 if (vcpu_has_run_once(vcpu) && unlikely(!irqchip_in_kernel(vcpu->kvm)))
358 static_branch_dec(&userspace_irqchip_in_use);
359
360 kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
361 kvm_timer_vcpu_terminate(vcpu);
362 kvm_pmu_vcpu_destroy(vcpu);
363
364 kvm_arm_vcpu_destroy(vcpu);
365 }
366
kvm_arch_vcpu_blocking(struct kvm_vcpu * vcpu)367 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
368 {
369
370 }
371
kvm_arch_vcpu_unblocking(struct kvm_vcpu * vcpu)372 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
373 {
374
375 }
376
kvm_arch_vcpu_load(struct kvm_vcpu * vcpu,int cpu)377 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
378 {
379 struct kvm_s2_mmu *mmu;
380 int *last_ran;
381
382 mmu = vcpu->arch.hw_mmu;
383 last_ran = this_cpu_ptr(mmu->last_vcpu_ran);
384
385 /*
386 * We guarantee that both TLBs and I-cache are private to each
387 * vcpu. If detecting that a vcpu from the same VM has
388 * previously run on the same physical CPU, call into the
389 * hypervisor code to nuke the relevant contexts.
390 *
391 * We might get preempted before the vCPU actually runs, but
392 * over-invalidation doesn't affect correctness.
393 */
394 if (*last_ran != vcpu->vcpu_id) {
395 kvm_call_hyp(__kvm_flush_cpu_context, mmu);
396 *last_ran = vcpu->vcpu_id;
397 }
398
399 vcpu->cpu = cpu;
400
401 kvm_vgic_load(vcpu);
402 kvm_timer_vcpu_load(vcpu);
403 if (has_vhe())
404 kvm_vcpu_load_sysregs_vhe(vcpu);
405 kvm_arch_vcpu_load_fp(vcpu);
406 kvm_vcpu_pmu_restore_guest(vcpu);
407 if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
408 kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
409
410 if (single_task_running())
411 vcpu_clear_wfx_traps(vcpu);
412 else
413 vcpu_set_wfx_traps(vcpu);
414
415 if (vcpu_has_ptrauth(vcpu))
416 vcpu_ptrauth_disable(vcpu);
417 kvm_arch_vcpu_load_debug_state_flags(vcpu);
418
419 if (!cpumask_test_cpu(smp_processor_id(), vcpu->kvm->arch.supported_cpus))
420 vcpu_set_on_unsupported_cpu(vcpu);
421 }
422
kvm_arch_vcpu_put(struct kvm_vcpu * vcpu)423 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
424 {
425 kvm_arch_vcpu_put_debug_state_flags(vcpu);
426 kvm_arch_vcpu_put_fp(vcpu);
427 if (has_vhe())
428 kvm_vcpu_put_sysregs_vhe(vcpu);
429 kvm_timer_vcpu_put(vcpu);
430 kvm_vgic_put(vcpu);
431 kvm_vcpu_pmu_restore_host(vcpu);
432 kvm_arm_vmid_clear_active();
433
434 vcpu_clear_on_unsupported_cpu(vcpu);
435 vcpu->cpu = -1;
436 }
437
kvm_arm_vcpu_power_off(struct kvm_vcpu * vcpu)438 void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
439 {
440 vcpu->arch.mp_state.mp_state = KVM_MP_STATE_STOPPED;
441 kvm_make_request(KVM_REQ_SLEEP, vcpu);
442 kvm_vcpu_kick(vcpu);
443 }
444
kvm_arm_vcpu_stopped(struct kvm_vcpu * vcpu)445 bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu)
446 {
447 return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_STOPPED;
448 }
449
kvm_arm_vcpu_suspend(struct kvm_vcpu * vcpu)450 static void kvm_arm_vcpu_suspend(struct kvm_vcpu *vcpu)
451 {
452 vcpu->arch.mp_state.mp_state = KVM_MP_STATE_SUSPENDED;
453 kvm_make_request(KVM_REQ_SUSPEND, vcpu);
454 kvm_vcpu_kick(vcpu);
455 }
456
kvm_arm_vcpu_suspended(struct kvm_vcpu * vcpu)457 static bool kvm_arm_vcpu_suspended(struct kvm_vcpu *vcpu)
458 {
459 return vcpu->arch.mp_state.mp_state == KVM_MP_STATE_SUSPENDED;
460 }
461
kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)462 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
463 struct kvm_mp_state *mp_state)
464 {
465 *mp_state = vcpu->arch.mp_state;
466
467 return 0;
468 }
469
kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)470 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
471 struct kvm_mp_state *mp_state)
472 {
473 int ret = 0;
474
475 switch (mp_state->mp_state) {
476 case KVM_MP_STATE_RUNNABLE:
477 vcpu->arch.mp_state = *mp_state;
478 break;
479 case KVM_MP_STATE_STOPPED:
480 kvm_arm_vcpu_power_off(vcpu);
481 break;
482 case KVM_MP_STATE_SUSPENDED:
483 kvm_arm_vcpu_suspend(vcpu);
484 break;
485 default:
486 ret = -EINVAL;
487 }
488
489 return ret;
490 }
491
492 /**
493 * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
494 * @v: The VCPU pointer
495 *
496 * If the guest CPU is not waiting for interrupts or an interrupt line is
497 * asserted, the CPU is by definition runnable.
498 */
kvm_arch_vcpu_runnable(struct kvm_vcpu * v)499 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
500 {
501 bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
502 return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
503 && !kvm_arm_vcpu_stopped(v) && !v->arch.pause);
504 }
505
kvm_arch_vcpu_in_kernel(struct kvm_vcpu * vcpu)506 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
507 {
508 return vcpu_mode_priv(vcpu);
509 }
510
511 #ifdef CONFIG_GUEST_PERF_EVENTS
kvm_arch_vcpu_get_ip(struct kvm_vcpu * vcpu)512 unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
513 {
514 return *vcpu_pc(vcpu);
515 }
516 #endif
517
kvm_vcpu_initialized(struct kvm_vcpu * vcpu)518 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
519 {
520 return vcpu->arch.target >= 0;
521 }
522
523 /*
524 * Handle both the initialisation that is being done when the vcpu is
525 * run for the first time, as well as the updates that must be
526 * performed each time we get a new thread dealing with this vcpu.
527 */
kvm_arch_vcpu_run_pid_change(struct kvm_vcpu * vcpu)528 int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
529 {
530 struct kvm *kvm = vcpu->kvm;
531 int ret;
532
533 if (!kvm_vcpu_initialized(vcpu))
534 return -ENOEXEC;
535
536 if (!kvm_arm_vcpu_is_finalized(vcpu))
537 return -EPERM;
538
539 ret = kvm_arch_vcpu_run_map_fp(vcpu);
540 if (ret)
541 return ret;
542
543 if (likely(vcpu_has_run_once(vcpu)))
544 return 0;
545
546 kvm_arm_vcpu_init_debug(vcpu);
547
548 if (likely(irqchip_in_kernel(kvm))) {
549 /*
550 * Map the VGIC hardware resources before running a vcpu the
551 * first time on this VM.
552 */
553 ret = kvm_vgic_map_resources(kvm);
554 if (ret)
555 return ret;
556 }
557
558 ret = kvm_timer_enable(vcpu);
559 if (ret)
560 return ret;
561
562 ret = kvm_arm_pmu_v3_enable(vcpu);
563 if (ret)
564 return ret;
565
566 if (!irqchip_in_kernel(kvm)) {
567 /*
568 * Tell the rest of the code that there are userspace irqchip
569 * VMs in the wild.
570 */
571 static_branch_inc(&userspace_irqchip_in_use);
572 }
573
574 /*
575 * Initialize traps for protected VMs.
576 * NOTE: Move to run in EL2 directly, rather than via a hypercall, once
577 * the code is in place for first run initialization at EL2.
578 */
579 if (kvm_vm_is_protected(kvm))
580 kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);
581
582 mutex_lock(&kvm->lock);
583 set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
584 mutex_unlock(&kvm->lock);
585
586 return ret;
587 }
588
kvm_arch_intc_initialized(struct kvm * kvm)589 bool kvm_arch_intc_initialized(struct kvm *kvm)
590 {
591 return vgic_initialized(kvm);
592 }
593
kvm_arm_halt_guest(struct kvm * kvm)594 void kvm_arm_halt_guest(struct kvm *kvm)
595 {
596 unsigned long i;
597 struct kvm_vcpu *vcpu;
598
599 kvm_for_each_vcpu(i, vcpu, kvm)
600 vcpu->arch.pause = true;
601 kvm_make_all_cpus_request(kvm, KVM_REQ_SLEEP);
602 }
603
kvm_arm_resume_guest(struct kvm * kvm)604 void kvm_arm_resume_guest(struct kvm *kvm)
605 {
606 unsigned long i;
607 struct kvm_vcpu *vcpu;
608
609 kvm_for_each_vcpu(i, vcpu, kvm) {
610 vcpu->arch.pause = false;
611 __kvm_vcpu_wake_up(vcpu);
612 }
613 }
614
kvm_vcpu_sleep(struct kvm_vcpu * vcpu)615 static void kvm_vcpu_sleep(struct kvm_vcpu *vcpu)
616 {
617 struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
618
619 rcuwait_wait_event(wait,
620 (!kvm_arm_vcpu_stopped(vcpu)) && (!vcpu->arch.pause),
621 TASK_INTERRUPTIBLE);
622
623 if (kvm_arm_vcpu_stopped(vcpu) || vcpu->arch.pause) {
624 /* Awaken to handle a signal, request we sleep again later. */
625 kvm_make_request(KVM_REQ_SLEEP, vcpu);
626 }
627
628 /*
629 * Make sure we will observe a potential reset request if we've
630 * observed a change to the power state. Pairs with the smp_wmb() in
631 * kvm_psci_vcpu_on().
632 */
633 smp_rmb();
634 }
635
636 /**
637 * kvm_vcpu_wfi - emulate Wait-For-Interrupt behavior
638 * @vcpu: The VCPU pointer
639 *
640 * Suspend execution of a vCPU until a valid wake event is detected, i.e. until
641 * the vCPU is runnable. The vCPU may or may not be scheduled out, depending
642 * on when a wake event arrives, e.g. there may already be a pending wake event.
643 */
kvm_vcpu_wfi(struct kvm_vcpu * vcpu)644 void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
645 {
646 /*
647 * Sync back the state of the GIC CPU interface so that we have
648 * the latest PMR and group enables. This ensures that
649 * kvm_arch_vcpu_runnable has up-to-date data to decide whether
650 * we have pending interrupts, e.g. when determining if the
651 * vCPU should block.
652 *
653 * For the same reason, we want to tell GICv4 that we need
654 * doorbells to be signalled, should an interrupt become pending.
655 */
656 preempt_disable();
657 kvm_vgic_vmcr_sync(vcpu);
658 vgic_v4_put(vcpu, true);
659 preempt_enable();
660
661 kvm_vcpu_halt(vcpu);
662 vcpu->arch.flags &= ~KVM_ARM64_WFIT;
663 kvm_clear_request(KVM_REQ_UNHALT, vcpu);
664
665 preempt_disable();
666 vgic_v4_load(vcpu);
667 preempt_enable();
668 }
669
kvm_vcpu_suspend(struct kvm_vcpu * vcpu)670 static int kvm_vcpu_suspend(struct kvm_vcpu *vcpu)
671 {
672 if (!kvm_arm_vcpu_suspended(vcpu))
673 return 1;
674
675 kvm_vcpu_wfi(vcpu);
676
677 /*
678 * The suspend state is sticky; we do not leave it until userspace
679 * explicitly marks the vCPU as runnable. Request that we suspend again
680 * later.
681 */
682 kvm_make_request(KVM_REQ_SUSPEND, vcpu);
683
684 /*
685 * Check to make sure the vCPU is actually runnable. If so, exit to
686 * userspace informing it of the wakeup condition.
687 */
688 if (kvm_arch_vcpu_runnable(vcpu)) {
689 memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
690 vcpu->run->system_event.type = KVM_SYSTEM_EVENT_WAKEUP;
691 vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
692 return 0;
693 }
694
695 /*
696 * Otherwise, we were unblocked to process a different event, such as a
697 * pending signal. Return 1 and allow kvm_arch_vcpu_ioctl_run() to
698 * process the event.
699 */
700 return 1;
701 }
702
703 /**
704 * check_vcpu_requests - check and handle pending vCPU requests
705 * @vcpu: the VCPU pointer
706 *
707 * Return: 1 if we should enter the guest
708 * 0 if we should exit to userspace
709 * < 0 if we should exit to userspace, where the return value indicates
710 * an error
711 */
check_vcpu_requests(struct kvm_vcpu * vcpu)712 static int check_vcpu_requests(struct kvm_vcpu *vcpu)
713 {
714 if (kvm_request_pending(vcpu)) {
715 if (kvm_check_request(KVM_REQ_SLEEP, vcpu))
716 kvm_vcpu_sleep(vcpu);
717
718 if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
719 kvm_reset_vcpu(vcpu);
720
721 /*
722 * Clear IRQ_PENDING requests that were made to guarantee
723 * that a VCPU sees new virtual interrupts.
724 */
725 kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);
726
727 if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu))
728 kvm_update_stolen_time(vcpu);
729
730 if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) {
731 /* The distributor enable bits were changed */
732 preempt_disable();
733 vgic_v4_put(vcpu, false);
734 vgic_v4_load(vcpu);
735 preempt_enable();
736 }
737
738 if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu))
739 kvm_pmu_handle_pmcr(vcpu,
740 __vcpu_sys_reg(vcpu, PMCR_EL0));
741
742 if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
743 return kvm_vcpu_suspend(vcpu);
744 }
745
746 return 1;
747 }
748
vcpu_mode_is_bad_32bit(struct kvm_vcpu * vcpu)749 static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
750 {
751 if (likely(!vcpu_mode_is_32bit(vcpu)))
752 return false;
753
754 return !kvm_supports_32bit_el0();
755 }
756
757 /**
758 * kvm_vcpu_exit_request - returns true if the VCPU should *not* enter the guest
759 * @vcpu: The VCPU pointer
760 * @ret: Pointer to write optional return code
761 *
762 * Returns: true if the VCPU needs to return to a preemptible + interruptible
763 * and skip guest entry.
764 *
765 * This function disambiguates between two different types of exits: exits to a
766 * preemptible + interruptible kernel context and exits to userspace. For an
767 * exit to userspace, this function will write the return code to ret and return
768 * true. For an exit to preemptible + interruptible kernel context (i.e. check
769 * for pending work and re-enter), return true without writing to ret.
770 */
kvm_vcpu_exit_request(struct kvm_vcpu * vcpu,int * ret)771 static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret)
772 {
773 struct kvm_run *run = vcpu->run;
774
775 /*
776 * If we're using a userspace irqchip, then check if we need
777 * to tell a userspace irqchip about timer or PMU level
778 * changes and if so, exit to userspace (the actual level
779 * state gets updated in kvm_timer_update_run and
780 * kvm_pmu_update_run below).
781 */
782 if (static_branch_unlikely(&userspace_irqchip_in_use)) {
783 if (kvm_timer_should_notify_user(vcpu) ||
784 kvm_pmu_should_notify_user(vcpu)) {
785 *ret = -EINTR;
786 run->exit_reason = KVM_EXIT_INTR;
787 return true;
788 }
789 }
790
791 if (unlikely(vcpu_on_unsupported_cpu(vcpu))) {
792 run->exit_reason = KVM_EXIT_FAIL_ENTRY;
793 run->fail_entry.hardware_entry_failure_reason = KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED;
794 run->fail_entry.cpu = smp_processor_id();
795 *ret = 0;
796 return true;
797 }
798
799 return kvm_request_pending(vcpu) ||
800 xfer_to_guest_mode_work_pending();
801 }
802
803 /*
804 * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while
805 * the vCPU is running.
806 *
807 * This must be noinstr as instrumentation may make use of RCU, and this is not
808 * safe during the EQS.
809 */
kvm_arm_vcpu_enter_exit(struct kvm_vcpu * vcpu)810 static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
811 {
812 int ret;
813
814 guest_state_enter_irqoff();
815 ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
816 guest_state_exit_irqoff();
817
818 return ret;
819 }
820
821 /**
822 * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
823 * @vcpu: The VCPU pointer
824 *
825 * This function is called through the VCPU_RUN ioctl called from user space. It
826 * will execute VM code in a loop until the time slice for the process is used
827 * or some emulation is needed from user space in which case the function will
828 * return with return value 0 and with the kvm_run structure filled in with the
829 * required data for the requested emulation.
830 */
kvm_arch_vcpu_ioctl_run(struct kvm_vcpu * vcpu)831 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
832 {
833 struct kvm_run *run = vcpu->run;
834 int ret;
835
836 if (run->exit_reason == KVM_EXIT_MMIO) {
837 ret = kvm_handle_mmio_return(vcpu);
838 if (ret)
839 return ret;
840 }
841
842 vcpu_load(vcpu);
843
844 if (run->immediate_exit) {
845 ret = -EINTR;
846 goto out;
847 }
848
849 kvm_sigset_activate(vcpu);
850
851 ret = 1;
852 run->exit_reason = KVM_EXIT_UNKNOWN;
853 run->flags = 0;
854 while (ret > 0) {
855 /*
856 * Check conditions before entering the guest
857 */
858 ret = xfer_to_guest_mode_handle_work(vcpu);
859 if (!ret)
860 ret = 1;
861
862 if (ret > 0)
863 ret = check_vcpu_requests(vcpu);
864
865 /*
866 * Preparing the interrupts to be injected also
867 * involves poking the GIC, which must be done in a
868 * non-preemptible context.
869 */
870 preempt_disable();
871
872 /*
873 * The VMID allocator only tracks active VMIDs per
874 * physical CPU, and therefore the VMID allocated may not be
875 * preserved on VMID roll-over if the task was preempted,
876 * making a thread's VMID inactive. So we need to call
877 * kvm_arm_vmid_update() in non-premptible context.
878 */
879 kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid);
880
881 kvm_pmu_flush_hwstate(vcpu);
882
883 local_irq_disable();
884
885 kvm_vgic_flush_hwstate(vcpu);
886
887 kvm_pmu_update_vcpu_events(vcpu);
888
889 /*
890 * Ensure we set mode to IN_GUEST_MODE after we disable
891 * interrupts and before the final VCPU requests check.
892 * See the comment in kvm_vcpu_exiting_guest_mode() and
893 * Documentation/virt/kvm/vcpu-requests.rst
894 */
895 smp_store_mb(vcpu->mode, IN_GUEST_MODE);
896
897 if (ret <= 0 || kvm_vcpu_exit_request(vcpu, &ret)) {
898 vcpu->mode = OUTSIDE_GUEST_MODE;
899 isb(); /* Ensure work in x_flush_hwstate is committed */
900 kvm_pmu_sync_hwstate(vcpu);
901 if (static_branch_unlikely(&userspace_irqchip_in_use))
902 kvm_timer_sync_user(vcpu);
903 kvm_vgic_sync_hwstate(vcpu);
904 local_irq_enable();
905 preempt_enable();
906 continue;
907 }
908
909 kvm_arm_setup_debug(vcpu);
910 kvm_arch_vcpu_ctxflush_fp(vcpu);
911
912 /**************************************************************
913 * Enter the guest
914 */
915 trace_kvm_entry(*vcpu_pc(vcpu));
916 guest_timing_enter_irqoff();
917
918 ret = kvm_arm_vcpu_enter_exit(vcpu);
919
920 vcpu->mode = OUTSIDE_GUEST_MODE;
921 vcpu->stat.exits++;
922 /*
923 * Back from guest
924 *************************************************************/
925
926 kvm_arm_clear_debug(vcpu);
927
928 /*
929 * We must sync the PMU state before the vgic state so
930 * that the vgic can properly sample the updated state of the
931 * interrupt line.
932 */
933 kvm_pmu_sync_hwstate(vcpu);
934
935 /*
936 * Sync the vgic state before syncing the timer state because
937 * the timer code needs to know if the virtual timer
938 * interrupts are active.
939 */
940 kvm_vgic_sync_hwstate(vcpu);
941
942 /*
943 * Sync the timer hardware state before enabling interrupts as
944 * we don't want vtimer interrupts to race with syncing the
945 * timer virtual interrupt state.
946 */
947 if (static_branch_unlikely(&userspace_irqchip_in_use))
948 kvm_timer_sync_user(vcpu);
949
950 kvm_arch_vcpu_ctxsync_fp(vcpu);
951
952 /*
953 * We must ensure that any pending interrupts are taken before
954 * we exit guest timing so that timer ticks are accounted as
955 * guest time. Transiently unmask interrupts so that any
956 * pending interrupts are taken.
957 *
958 * Per ARM DDI 0487G.b section D1.13.4, an ISB (or other
959 * context synchronization event) is necessary to ensure that
960 * pending interrupts are taken.
961 */
962 if (ARM_EXCEPTION_CODE(ret) == ARM_EXCEPTION_IRQ) {
963 local_irq_enable();
964 isb();
965 local_irq_disable();
966 }
967
968 guest_timing_exit_irqoff();
969
970 local_irq_enable();
971
972 trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
973
974 /* Exit types that need handling before we can be preempted */
975 handle_exit_early(vcpu, ret);
976
977 preempt_enable();
978
979 /*
980 * The ARMv8 architecture doesn't give the hypervisor
981 * a mechanism to prevent a guest from dropping to AArch32 EL0
982 * if implemented by the CPU. If we spot the guest in such
983 * state and that we decided it wasn't supposed to do so (like
984 * with the asymmetric AArch32 case), return to userspace with
985 * a fatal error.
986 */
987 if (vcpu_mode_is_bad_32bit(vcpu)) {
988 /*
989 * As we have caught the guest red-handed, decide that
990 * it isn't fit for purpose anymore by making the vcpu
991 * invalid. The VMM can try and fix it by issuing a
992 * KVM_ARM_VCPU_INIT if it really wants to.
993 */
994 vcpu->arch.target = -1;
995 ret = ARM_EXCEPTION_IL;
996 }
997
998 ret = handle_exit(vcpu, ret);
999 }
1000
1001 /* Tell userspace about in-kernel device output levels */
1002 if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
1003 kvm_timer_update_run(vcpu);
1004 kvm_pmu_update_run(vcpu);
1005 }
1006
1007 kvm_sigset_deactivate(vcpu);
1008
1009 out:
1010 /*
1011 * In the unlikely event that we are returning to userspace
1012 * with pending exceptions or PC adjustment, commit these
1013 * adjustments in order to give userspace a consistent view of
1014 * the vcpu state. Note that this relies on __kvm_adjust_pc()
1015 * being preempt-safe on VHE.
1016 */
1017 if (unlikely(vcpu->arch.flags & (KVM_ARM64_PENDING_EXCEPTION |
1018 KVM_ARM64_INCREMENT_PC)))
1019 kvm_call_hyp(__kvm_adjust_pc, vcpu);
1020
1021 vcpu_put(vcpu);
1022 return ret;
1023 }
1024
vcpu_interrupt_line(struct kvm_vcpu * vcpu,int number,bool level)1025 static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
1026 {
1027 int bit_index;
1028 bool set;
1029 unsigned long *hcr;
1030
1031 if (number == KVM_ARM_IRQ_CPU_IRQ)
1032 bit_index = __ffs(HCR_VI);
1033 else /* KVM_ARM_IRQ_CPU_FIQ */
1034 bit_index = __ffs(HCR_VF);
1035
1036 hcr = vcpu_hcr(vcpu);
1037 if (level)
1038 set = test_and_set_bit(bit_index, hcr);
1039 else
1040 set = test_and_clear_bit(bit_index, hcr);
1041
1042 /*
1043 * If we didn't change anything, no need to wake up or kick other CPUs
1044 */
1045 if (set == level)
1046 return 0;
1047
1048 /*
1049 * The vcpu irq_lines field was updated, wake up sleeping VCPUs and
1050 * trigger a world-switch round on the running physical CPU to set the
1051 * virtual IRQ/FIQ fields in the HCR appropriately.
1052 */
1053 kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
1054 kvm_vcpu_kick(vcpu);
1055
1056 return 0;
1057 }
1058
kvm_vm_ioctl_irq_line(struct kvm * kvm,struct kvm_irq_level * irq_level,bool line_status)1059 int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
1060 bool line_status)
1061 {
1062 u32 irq = irq_level->irq;
1063 unsigned int irq_type, vcpu_idx, irq_num;
1064 int nrcpus = atomic_read(&kvm->online_vcpus);
1065 struct kvm_vcpu *vcpu = NULL;
1066 bool level = irq_level->level;
1067
1068 irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
1069 vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
1070 vcpu_idx += ((irq >> KVM_ARM_IRQ_VCPU2_SHIFT) & KVM_ARM_IRQ_VCPU2_MASK) * (KVM_ARM_IRQ_VCPU_MASK + 1);
1071 irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;
1072
1073 trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level);
1074
1075 switch (irq_type) {
1076 case KVM_ARM_IRQ_TYPE_CPU:
1077 if (irqchip_in_kernel(kvm))
1078 return -ENXIO;
1079
1080 if (vcpu_idx >= nrcpus)
1081 return -EINVAL;
1082
1083 vcpu = kvm_get_vcpu(kvm, vcpu_idx);
1084 if (!vcpu)
1085 return -EINVAL;
1086
1087 if (irq_num > KVM_ARM_IRQ_CPU_FIQ)
1088 return -EINVAL;
1089
1090 return vcpu_interrupt_line(vcpu, irq_num, level);
1091 case KVM_ARM_IRQ_TYPE_PPI:
1092 if (!irqchip_in_kernel(kvm))
1093 return -ENXIO;
1094
1095 if (vcpu_idx >= nrcpus)
1096 return -EINVAL;
1097
1098 vcpu = kvm_get_vcpu(kvm, vcpu_idx);
1099 if (!vcpu)
1100 return -EINVAL;
1101
1102 if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
1103 return -EINVAL;
1104
1105 return kvm_vgic_inject_irq(kvm, vcpu->vcpu_id, irq_num, level, NULL);
1106 case KVM_ARM_IRQ_TYPE_SPI:
1107 if (!irqchip_in_kernel(kvm))
1108 return -ENXIO;
1109
1110 if (irq_num < VGIC_NR_PRIVATE_IRQS)
1111 return -EINVAL;
1112
1113 return kvm_vgic_inject_irq(kvm, 0, irq_num, level, NULL);
1114 }
1115
1116 return -EINVAL;
1117 }
1118
kvm_vcpu_set_target(struct kvm_vcpu * vcpu,const struct kvm_vcpu_init * init)1119 static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
1120 const struct kvm_vcpu_init *init)
1121 {
1122 unsigned int i, ret;
1123 u32 phys_target = kvm_target_cpu();
1124
1125 if (init->target != phys_target)
1126 return -EINVAL;
1127
1128 /*
1129 * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
1130 * use the same target.
1131 */
1132 if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
1133 return -EINVAL;
1134
1135 /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
1136 for (i = 0; i < sizeof(init->features) * 8; i++) {
1137 bool set = (init->features[i / 32] & (1 << (i % 32)));
1138
1139 if (set && i >= KVM_VCPU_MAX_FEATURES)
1140 return -ENOENT;
1141
1142 /*
1143 * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
1144 * use the same feature set.
1145 */
1146 if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
1147 test_bit(i, vcpu->arch.features) != set)
1148 return -EINVAL;
1149
1150 if (set)
1151 set_bit(i, vcpu->arch.features);
1152 }
1153
1154 vcpu->arch.target = phys_target;
1155
1156 /* Now we know what it is, we can reset it. */
1157 ret = kvm_reset_vcpu(vcpu);
1158 if (ret) {
1159 vcpu->arch.target = -1;
1160 bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
1161 }
1162
1163 return ret;
1164 }
1165
kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu * vcpu,struct kvm_vcpu_init * init)1166 static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
1167 struct kvm_vcpu_init *init)
1168 {
1169 int ret;
1170
1171 ret = kvm_vcpu_set_target(vcpu, init);
1172 if (ret)
1173 return ret;
1174
1175 /*
1176 * Ensure a rebooted VM will fault in RAM pages and detect if the
1177 * guest MMU is turned off and flush the caches as needed.
1178 *
1179 * S2FWB enforces all memory accesses to RAM being cacheable,
1180 * ensuring that the data side is always coherent. We still
1181 * need to invalidate the I-cache though, as FWB does *not*
1182 * imply CTR_EL0.DIC.
1183 */
1184 if (vcpu_has_run_once(vcpu)) {
1185 if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
1186 stage2_unmap_vm(vcpu->kvm);
1187 else
1188 icache_inval_all_pou();
1189 }
1190
1191 vcpu_reset_hcr(vcpu);
1192 vcpu->arch.cptr_el2 = CPTR_EL2_DEFAULT;
1193
1194 /*
1195 * Handle the "start in power-off" case.
1196 */
1197 if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
1198 kvm_arm_vcpu_power_off(vcpu);
1199 else
1200 vcpu->arch.mp_state.mp_state = KVM_MP_STATE_RUNNABLE;
1201
1202 return 0;
1203 }
1204
kvm_arm_vcpu_set_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1205 static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
1206 struct kvm_device_attr *attr)
1207 {
1208 int ret = -ENXIO;
1209
1210 switch (attr->group) {
1211 default:
1212 ret = kvm_arm_vcpu_arch_set_attr(vcpu, attr);
1213 break;
1214 }
1215
1216 return ret;
1217 }
1218
kvm_arm_vcpu_get_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1219 static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
1220 struct kvm_device_attr *attr)
1221 {
1222 int ret = -ENXIO;
1223
1224 switch (attr->group) {
1225 default:
1226 ret = kvm_arm_vcpu_arch_get_attr(vcpu, attr);
1227 break;
1228 }
1229
1230 return ret;
1231 }
1232
kvm_arm_vcpu_has_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1233 static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
1234 struct kvm_device_attr *attr)
1235 {
1236 int ret = -ENXIO;
1237
1238 switch (attr->group) {
1239 default:
1240 ret = kvm_arm_vcpu_arch_has_attr(vcpu, attr);
1241 break;
1242 }
1243
1244 return ret;
1245 }
1246
kvm_arm_vcpu_get_events(struct kvm_vcpu * vcpu,struct kvm_vcpu_events * events)1247 static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
1248 struct kvm_vcpu_events *events)
1249 {
1250 memset(events, 0, sizeof(*events));
1251
1252 return __kvm_arm_vcpu_get_events(vcpu, events);
1253 }
1254
kvm_arm_vcpu_set_events(struct kvm_vcpu * vcpu,struct kvm_vcpu_events * events)1255 static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
1256 struct kvm_vcpu_events *events)
1257 {
1258 int i;
1259
1260 /* check whether the reserved field is zero */
1261 for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
1262 if (events->reserved[i])
1263 return -EINVAL;
1264
1265 /* check whether the pad field is zero */
1266 for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
1267 if (events->exception.pad[i])
1268 return -EINVAL;
1269
1270 return __kvm_arm_vcpu_set_events(vcpu, events);
1271 }
1272
kvm_arch_vcpu_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)1273 long kvm_arch_vcpu_ioctl(struct file *filp,
1274 unsigned int ioctl, unsigned long arg)
1275 {
1276 struct kvm_vcpu *vcpu = filp->private_data;
1277 void __user *argp = (void __user *)arg;
1278 struct kvm_device_attr attr;
1279 long r;
1280
1281 switch (ioctl) {
1282 case KVM_ARM_VCPU_INIT: {
1283 struct kvm_vcpu_init init;
1284
1285 r = -EFAULT;
1286 if (copy_from_user(&init, argp, sizeof(init)))
1287 break;
1288
1289 r = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init);
1290 break;
1291 }
1292 case KVM_SET_ONE_REG:
1293 case KVM_GET_ONE_REG: {
1294 struct kvm_one_reg reg;
1295
1296 r = -ENOEXEC;
1297 if (unlikely(!kvm_vcpu_initialized(vcpu)))
1298 break;
1299
1300 r = -EFAULT;
1301 if (copy_from_user(®, argp, sizeof(reg)))
1302 break;
1303
1304 /*
1305 * We could owe a reset due to PSCI. Handle the pending reset
1306 * here to ensure userspace register accesses are ordered after
1307 * the reset.
1308 */
1309 if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
1310 kvm_reset_vcpu(vcpu);
1311
1312 if (ioctl == KVM_SET_ONE_REG)
1313 r = kvm_arm_set_reg(vcpu, ®);
1314 else
1315 r = kvm_arm_get_reg(vcpu, ®);
1316 break;
1317 }
1318 case KVM_GET_REG_LIST: {
1319 struct kvm_reg_list __user *user_list = argp;
1320 struct kvm_reg_list reg_list;
1321 unsigned n;
1322
1323 r = -ENOEXEC;
1324 if (unlikely(!kvm_vcpu_initialized(vcpu)))
1325 break;
1326
1327 r = -EPERM;
1328 if (!kvm_arm_vcpu_is_finalized(vcpu))
1329 break;
1330
1331 r = -EFAULT;
1332 if (copy_from_user(®_list, user_list, sizeof(reg_list)))
1333 break;
1334 n = reg_list.n;
1335 reg_list.n = kvm_arm_num_regs(vcpu);
1336 if (copy_to_user(user_list, ®_list, sizeof(reg_list)))
1337 break;
1338 r = -E2BIG;
1339 if (n < reg_list.n)
1340 break;
1341 r = kvm_arm_copy_reg_indices(vcpu, user_list->reg);
1342 break;
1343 }
1344 case KVM_SET_DEVICE_ATTR: {
1345 r = -EFAULT;
1346 if (copy_from_user(&attr, argp, sizeof(attr)))
1347 break;
1348 r = kvm_arm_vcpu_set_attr(vcpu, &attr);
1349 break;
1350 }
1351 case KVM_GET_DEVICE_ATTR: {
1352 r = -EFAULT;
1353 if (copy_from_user(&attr, argp, sizeof(attr)))
1354 break;
1355 r = kvm_arm_vcpu_get_attr(vcpu, &attr);
1356 break;
1357 }
1358 case KVM_HAS_DEVICE_ATTR: {
1359 r = -EFAULT;
1360 if (copy_from_user(&attr, argp, sizeof(attr)))
1361 break;
1362 r = kvm_arm_vcpu_has_attr(vcpu, &attr);
1363 break;
1364 }
1365 case KVM_GET_VCPU_EVENTS: {
1366 struct kvm_vcpu_events events;
1367
1368 if (kvm_arm_vcpu_get_events(vcpu, &events))
1369 return -EINVAL;
1370
1371 if (copy_to_user(argp, &events, sizeof(events)))
1372 return -EFAULT;
1373
1374 return 0;
1375 }
1376 case KVM_SET_VCPU_EVENTS: {
1377 struct kvm_vcpu_events events;
1378
1379 if (copy_from_user(&events, argp, sizeof(events)))
1380 return -EFAULT;
1381
1382 return kvm_arm_vcpu_set_events(vcpu, &events);
1383 }
1384 case KVM_ARM_VCPU_FINALIZE: {
1385 int what;
1386
1387 if (!kvm_vcpu_initialized(vcpu))
1388 return -ENOEXEC;
1389
1390 if (get_user(what, (const int __user *)argp))
1391 return -EFAULT;
1392
1393 return kvm_arm_vcpu_finalize(vcpu, what);
1394 }
1395 default:
1396 r = -EINVAL;
1397 }
1398
1399 return r;
1400 }
1401
kvm_arch_sync_dirty_log(struct kvm * kvm,struct kvm_memory_slot * memslot)1402 void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
1403 {
1404
1405 }
1406
kvm_arch_flush_remote_tlbs_memslot(struct kvm * kvm,const struct kvm_memory_slot * memslot)1407 void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
1408 const struct kvm_memory_slot *memslot)
1409 {
1410 kvm_flush_remote_tlbs(kvm);
1411 }
1412
kvm_vm_ioctl_set_device_addr(struct kvm * kvm,struct kvm_arm_device_addr * dev_addr)1413 static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
1414 struct kvm_arm_device_addr *dev_addr)
1415 {
1416 unsigned long dev_id, type;
1417
1418 dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >>
1419 KVM_ARM_DEVICE_ID_SHIFT;
1420 type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >>
1421 KVM_ARM_DEVICE_TYPE_SHIFT;
1422
1423 switch (dev_id) {
1424 case KVM_ARM_DEVICE_VGIC_V2:
1425 if (!vgic_present)
1426 return -ENXIO;
1427 return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
1428 default:
1429 return -ENODEV;
1430 }
1431 }
1432
kvm_arch_vm_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)1433 long kvm_arch_vm_ioctl(struct file *filp,
1434 unsigned int ioctl, unsigned long arg)
1435 {
1436 struct kvm *kvm = filp->private_data;
1437 void __user *argp = (void __user *)arg;
1438
1439 switch (ioctl) {
1440 case KVM_CREATE_IRQCHIP: {
1441 int ret;
1442 if (!vgic_present)
1443 return -ENXIO;
1444 mutex_lock(&kvm->lock);
1445 ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
1446 mutex_unlock(&kvm->lock);
1447 return ret;
1448 }
1449 case KVM_ARM_SET_DEVICE_ADDR: {
1450 struct kvm_arm_device_addr dev_addr;
1451
1452 if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
1453 return -EFAULT;
1454 return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
1455 }
1456 case KVM_ARM_PREFERRED_TARGET: {
1457 struct kvm_vcpu_init init;
1458
1459 kvm_vcpu_preferred_target(&init);
1460
1461 if (copy_to_user(argp, &init, sizeof(init)))
1462 return -EFAULT;
1463
1464 return 0;
1465 }
1466 case KVM_ARM_MTE_COPY_TAGS: {
1467 struct kvm_arm_copy_mte_tags copy_tags;
1468
1469 if (copy_from_user(©_tags, argp, sizeof(copy_tags)))
1470 return -EFAULT;
1471 return kvm_vm_ioctl_mte_copy_tags(kvm, ©_tags);
1472 }
1473 default:
1474 return -EINVAL;
1475 }
1476 }
1477
nvhe_percpu_size(void)1478 static unsigned long nvhe_percpu_size(void)
1479 {
1480 return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) -
1481 (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_start);
1482 }
1483
nvhe_percpu_order(void)1484 static unsigned long nvhe_percpu_order(void)
1485 {
1486 unsigned long size = nvhe_percpu_size();
1487
1488 return size ? get_order(size) : 0;
1489 }
1490
1491 /* A lookup table holding the hypervisor VA for each vector slot */
1492 static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS];
1493
kvm_init_vector_slot(void * base,enum arm64_hyp_spectre_vector slot)1494 static void kvm_init_vector_slot(void *base, enum arm64_hyp_spectre_vector slot)
1495 {
1496 hyp_spectre_vector_selector[slot] = __kvm_vector_slot2addr(base, slot);
1497 }
1498
kvm_init_vector_slots(void)1499 static int kvm_init_vector_slots(void)
1500 {
1501 int err;
1502 void *base;
1503
1504 base = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
1505 kvm_init_vector_slot(base, HYP_VECTOR_DIRECT);
1506
1507 base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
1508 kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT);
1509
1510 if (kvm_system_needs_idmapped_vectors() &&
1511 !is_protected_kvm_enabled()) {
1512 err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs),
1513 __BP_HARDEN_HYP_VECS_SZ, &base);
1514 if (err)
1515 return err;
1516 }
1517
1518 kvm_init_vector_slot(base, HYP_VECTOR_INDIRECT);
1519 kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_INDIRECT);
1520 return 0;
1521 }
1522
cpu_prepare_hyp_mode(int cpu)1523 static void cpu_prepare_hyp_mode(int cpu)
1524 {
1525 struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
1526 unsigned long tcr;
1527
1528 /*
1529 * Calculate the raw per-cpu offset without a translation from the
1530 * kernel's mapping to the linear mapping, and store it in tpidr_el2
1531 * so that we can use adr_l to access per-cpu variables in EL2.
1532 * Also drop the KASAN tag which gets in the way...
1533 */
1534 params->tpidr_el2 = (unsigned long)kasan_reset_tag(per_cpu_ptr_nvhe_sym(__per_cpu_start, cpu)) -
1535 (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
1536
1537 params->mair_el2 = read_sysreg(mair_el1);
1538
1539 /*
1540 * The ID map may be configured to use an extended virtual address
1541 * range. This is only the case if system RAM is out of range for the
1542 * currently configured page size and VA_BITS, in which case we will
1543 * also need the extended virtual range for the HYP ID map, or we won't
1544 * be able to enable the EL2 MMU.
1545 *
1546 * However, at EL2, there is only one TTBR register, and we can't switch
1547 * between translation tables *and* update TCR_EL2.T0SZ at the same
1548 * time. Bottom line: we need to use the extended range with *both* our
1549 * translation tables.
1550 *
1551 * So use the same T0SZ value we use for the ID map.
1552 */
1553 tcr = (read_sysreg(tcr_el1) & TCR_EL2_MASK) | TCR_EL2_RES1;
1554 tcr &= ~TCR_T0SZ_MASK;
1555 tcr |= (idmap_t0sz & GENMASK(TCR_TxSZ_WIDTH - 1, 0)) << TCR_T0SZ_OFFSET;
1556 params->tcr_el2 = tcr;
1557
1558 params->pgd_pa = kvm_mmu_get_httbr();
1559 if (is_protected_kvm_enabled())
1560 params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
1561 else
1562 params->hcr_el2 = HCR_HOST_NVHE_FLAGS;
1563 params->vttbr = params->vtcr = 0;
1564
1565 /*
1566 * Flush the init params from the data cache because the struct will
1567 * be read while the MMU is off.
1568 */
1569 kvm_flush_dcache_to_poc(params, sizeof(*params));
1570 }
1571
hyp_install_host_vector(void)1572 static void hyp_install_host_vector(void)
1573 {
1574 struct kvm_nvhe_init_params *params;
1575 struct arm_smccc_res res;
1576
1577 /* Switch from the HYP stub to our own HYP init vector */
1578 __hyp_set_vectors(kvm_get_idmap_vector());
1579
1580 /*
1581 * Call initialization code, and switch to the full blown HYP code.
1582 * If the cpucaps haven't been finalized yet, something has gone very
1583 * wrong, and hyp will crash and burn when it uses any
1584 * cpus_have_const_cap() wrapper.
1585 */
1586 BUG_ON(!system_capabilities_finalized());
1587 params = this_cpu_ptr_nvhe_sym(kvm_init_params);
1588 arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
1589 WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
1590 }
1591
cpu_init_hyp_mode(void)1592 static void cpu_init_hyp_mode(void)
1593 {
1594 hyp_install_host_vector();
1595
1596 /*
1597 * Disabling SSBD on a non-VHE system requires us to enable SSBS
1598 * at EL2.
1599 */
1600 if (this_cpu_has_cap(ARM64_SSBS) &&
1601 arm64_get_spectre_v4_state() == SPECTRE_VULNERABLE) {
1602 kvm_call_hyp_nvhe(__kvm_enable_ssbs);
1603 }
1604 }
1605
cpu_hyp_reset(void)1606 static void cpu_hyp_reset(void)
1607 {
1608 if (!is_kernel_in_hyp_mode())
1609 __hyp_reset_vectors();
1610 }
1611
1612 /*
1613 * EL2 vectors can be mapped and rerouted in a number of ways,
1614 * depending on the kernel configuration and CPU present:
1615 *
1616 * - If the CPU is affected by Spectre-v2, the hardening sequence is
1617 * placed in one of the vector slots, which is executed before jumping
1618 * to the real vectors.
1619 *
1620 * - If the CPU also has the ARM64_SPECTRE_V3A cap, the slot
1621 * containing the hardening sequence is mapped next to the idmap page,
1622 * and executed before jumping to the real vectors.
1623 *
1624 * - If the CPU only has the ARM64_SPECTRE_V3A cap, then an
1625 * empty slot is selected, mapped next to the idmap page, and
1626 * executed before jumping to the real vectors.
1627 *
1628 * Note that ARM64_SPECTRE_V3A is somewhat incompatible with
1629 * VHE, as we don't have hypervisor-specific mappings. If the system
1630 * is VHE and yet selects this capability, it will be ignored.
1631 */
cpu_set_hyp_vector(void)1632 static void cpu_set_hyp_vector(void)
1633 {
1634 struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
1635 void *vector = hyp_spectre_vector_selector[data->slot];
1636
1637 if (!is_protected_kvm_enabled())
1638 *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector;
1639 else
1640 kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot);
1641 }
1642
cpu_hyp_init_context(void)1643 static void cpu_hyp_init_context(void)
1644 {
1645 kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);
1646
1647 if (!is_kernel_in_hyp_mode())
1648 cpu_init_hyp_mode();
1649 }
1650
cpu_hyp_init_features(void)1651 static void cpu_hyp_init_features(void)
1652 {
1653 cpu_set_hyp_vector();
1654 kvm_arm_init_debug();
1655
1656 if (is_kernel_in_hyp_mode())
1657 kvm_timer_init_vhe();
1658
1659 if (vgic_present)
1660 kvm_vgic_init_cpu_hardware();
1661 }
1662
cpu_hyp_reinit(void)1663 static void cpu_hyp_reinit(void)
1664 {
1665 cpu_hyp_reset();
1666 cpu_hyp_init_context();
1667 cpu_hyp_init_features();
1668 }
1669
_kvm_arch_hardware_enable(void * discard)1670 static void _kvm_arch_hardware_enable(void *discard)
1671 {
1672 if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
1673 cpu_hyp_reinit();
1674 __this_cpu_write(kvm_arm_hardware_enabled, 1);
1675 }
1676 }
1677
kvm_arch_hardware_enable(void)1678 int kvm_arch_hardware_enable(void)
1679 {
1680 _kvm_arch_hardware_enable(NULL);
1681 return 0;
1682 }
1683
_kvm_arch_hardware_disable(void * discard)1684 static void _kvm_arch_hardware_disable(void *discard)
1685 {
1686 if (__this_cpu_read(kvm_arm_hardware_enabled)) {
1687 cpu_hyp_reset();
1688 __this_cpu_write(kvm_arm_hardware_enabled, 0);
1689 }
1690 }
1691
kvm_arch_hardware_disable(void)1692 void kvm_arch_hardware_disable(void)
1693 {
1694 if (!is_protected_kvm_enabled())
1695 _kvm_arch_hardware_disable(NULL);
1696 }
1697
1698 #ifdef CONFIG_CPU_PM
hyp_init_cpu_pm_notifier(struct notifier_block * self,unsigned long cmd,void * v)1699 static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
1700 unsigned long cmd,
1701 void *v)
1702 {
1703 /*
1704 * kvm_arm_hardware_enabled is left with its old value over
1705 * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
1706 * re-enable hyp.
1707 */
1708 switch (cmd) {
1709 case CPU_PM_ENTER:
1710 if (__this_cpu_read(kvm_arm_hardware_enabled))
1711 /*
1712 * don't update kvm_arm_hardware_enabled here
1713 * so that the hardware will be re-enabled
1714 * when we resume. See below.
1715 */
1716 cpu_hyp_reset();
1717
1718 return NOTIFY_OK;
1719 case CPU_PM_ENTER_FAILED:
1720 case CPU_PM_EXIT:
1721 if (__this_cpu_read(kvm_arm_hardware_enabled))
1722 /* The hardware was enabled before suspend. */
1723 cpu_hyp_reinit();
1724
1725 return NOTIFY_OK;
1726
1727 default:
1728 return NOTIFY_DONE;
1729 }
1730 }
1731
1732 static struct notifier_block hyp_init_cpu_pm_nb = {
1733 .notifier_call = hyp_init_cpu_pm_notifier,
1734 };
1735
hyp_cpu_pm_init(void)1736 static void hyp_cpu_pm_init(void)
1737 {
1738 if (!is_protected_kvm_enabled())
1739 cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
1740 }
hyp_cpu_pm_exit(void)1741 static void hyp_cpu_pm_exit(void)
1742 {
1743 if (!is_protected_kvm_enabled())
1744 cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
1745 }
1746 #else
hyp_cpu_pm_init(void)1747 static inline void hyp_cpu_pm_init(void)
1748 {
1749 }
hyp_cpu_pm_exit(void)1750 static inline void hyp_cpu_pm_exit(void)
1751 {
1752 }
1753 #endif
1754
init_cpu_logical_map(void)1755 static void init_cpu_logical_map(void)
1756 {
1757 unsigned int cpu;
1758
1759 /*
1760 * Copy the MPIDR <-> logical CPU ID mapping to hyp.
1761 * Only copy the set of online CPUs whose features have been checked
1762 * against the finalized system capabilities. The hypervisor will not
1763 * allow any other CPUs from the `possible` set to boot.
1764 */
1765 for_each_online_cpu(cpu)
1766 hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu);
1767 }
1768
1769 #define init_psci_0_1_impl_state(config, what) \
1770 config.psci_0_1_ ## what ## _implemented = psci_ops.what
1771
init_psci_relay(void)1772 static bool init_psci_relay(void)
1773 {
1774 /*
1775 * If PSCI has not been initialized, protected KVM cannot install
1776 * itself on newly booted CPUs.
1777 */
1778 if (!psci_ops.get_version) {
1779 kvm_err("Cannot initialize protected mode without PSCI\n");
1780 return false;
1781 }
1782
1783 kvm_host_psci_config.version = psci_ops.get_version();
1784
1785 if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
1786 kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
1787 init_psci_0_1_impl_state(kvm_host_psci_config, cpu_suspend);
1788 init_psci_0_1_impl_state(kvm_host_psci_config, cpu_on);
1789 init_psci_0_1_impl_state(kvm_host_psci_config, cpu_off);
1790 init_psci_0_1_impl_state(kvm_host_psci_config, migrate);
1791 }
1792 return true;
1793 }
1794
init_subsystems(void)1795 static int init_subsystems(void)
1796 {
1797 int err = 0;
1798
1799 /*
1800 * Enable hardware so that subsystem initialisation can access EL2.
1801 */
1802 on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);
1803
1804 /*
1805 * Register CPU lower-power notifier
1806 */
1807 hyp_cpu_pm_init();
1808
1809 /*
1810 * Init HYP view of VGIC
1811 */
1812 err = kvm_vgic_hyp_init();
1813 switch (err) {
1814 case 0:
1815 vgic_present = true;
1816 break;
1817 case -ENODEV:
1818 case -ENXIO:
1819 vgic_present = false;
1820 err = 0;
1821 break;
1822 default:
1823 goto out;
1824 }
1825
1826 /*
1827 * Init HYP architected timer support
1828 */
1829 err = kvm_timer_hyp_init(vgic_present);
1830 if (err)
1831 goto out;
1832
1833 kvm_register_perf_callbacks(NULL);
1834
1835 out:
1836 if (err || !is_protected_kvm_enabled())
1837 on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
1838
1839 return err;
1840 }
1841
teardown_hyp_mode(void)1842 static void teardown_hyp_mode(void)
1843 {
1844 int cpu;
1845
1846 free_hyp_pgds();
1847 for_each_possible_cpu(cpu) {
1848 free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
1849 free_pages(kvm_arm_hyp_percpu_base[cpu], nvhe_percpu_order());
1850 }
1851 }
1852
do_pkvm_init(u32 hyp_va_bits)1853 static int do_pkvm_init(u32 hyp_va_bits)
1854 {
1855 void *per_cpu_base = kvm_ksym_ref(kvm_arm_hyp_percpu_base);
1856 int ret;
1857
1858 preempt_disable();
1859 cpu_hyp_init_context();
1860 ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size,
1861 num_possible_cpus(), kern_hyp_va(per_cpu_base),
1862 hyp_va_bits);
1863 cpu_hyp_init_features();
1864
1865 /*
1866 * The stub hypercalls are now disabled, so set our local flag to
1867 * prevent a later re-init attempt in kvm_arch_hardware_enable().
1868 */
1869 __this_cpu_write(kvm_arm_hardware_enabled, 1);
1870 preempt_enable();
1871
1872 return ret;
1873 }
1874
kvm_hyp_init_protection(u32 hyp_va_bits)1875 static int kvm_hyp_init_protection(u32 hyp_va_bits)
1876 {
1877 void *addr = phys_to_virt(hyp_mem_base);
1878 int ret;
1879
1880 kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
1881 kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
1882 kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
1883 kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
1884 kvm_nvhe_sym(id_aa64isar2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
1885 kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
1886 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
1887 kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1);
1888
1889 ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
1890 if (ret)
1891 return ret;
1892
1893 ret = do_pkvm_init(hyp_va_bits);
1894 if (ret)
1895 return ret;
1896
1897 free_hyp_pgds();
1898
1899 return 0;
1900 }
1901
1902 /**
1903 * Inits Hyp-mode on all online CPUs
1904 */
init_hyp_mode(void)1905 static int init_hyp_mode(void)
1906 {
1907 u32 hyp_va_bits;
1908 int cpu;
1909 int err = -ENOMEM;
1910
1911 /*
1912 * The protected Hyp-mode cannot be initialized if the memory pool
1913 * allocation has failed.
1914 */
1915 if (is_protected_kvm_enabled() && !hyp_mem_base)
1916 goto out_err;
1917
1918 /*
1919 * Allocate Hyp PGD and setup Hyp identity mapping
1920 */
1921 err = kvm_mmu_init(&hyp_va_bits);
1922 if (err)
1923 goto out_err;
1924
1925 /*
1926 * Allocate stack pages for Hypervisor-mode
1927 */
1928 for_each_possible_cpu(cpu) {
1929 unsigned long stack_page;
1930
1931 stack_page = __get_free_page(GFP_KERNEL);
1932 if (!stack_page) {
1933 err = -ENOMEM;
1934 goto out_err;
1935 }
1936
1937 per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
1938 }
1939
1940 /*
1941 * Allocate and initialize pages for Hypervisor-mode percpu regions.
1942 */
1943 for_each_possible_cpu(cpu) {
1944 struct page *page;
1945 void *page_addr;
1946
1947 page = alloc_pages(GFP_KERNEL, nvhe_percpu_order());
1948 if (!page) {
1949 err = -ENOMEM;
1950 goto out_err;
1951 }
1952
1953 page_addr = page_address(page);
1954 memcpy(page_addr, CHOOSE_NVHE_SYM(__per_cpu_start), nvhe_percpu_size());
1955 kvm_arm_hyp_percpu_base[cpu] = (unsigned long)page_addr;
1956 }
1957
1958 /*
1959 * Map the Hyp-code called directly from the host
1960 */
1961 err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start),
1962 kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC);
1963 if (err) {
1964 kvm_err("Cannot map world-switch code\n");
1965 goto out_err;
1966 }
1967
1968 err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
1969 kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
1970 if (err) {
1971 kvm_err("Cannot map .hyp.rodata section\n");
1972 goto out_err;
1973 }
1974
1975 err = create_hyp_mappings(kvm_ksym_ref(__start_rodata),
1976 kvm_ksym_ref(__end_rodata), PAGE_HYP_RO);
1977 if (err) {
1978 kvm_err("Cannot map rodata section\n");
1979 goto out_err;
1980 }
1981
1982 /*
1983 * .hyp.bss is guaranteed to be placed at the beginning of the .bss
1984 * section thanks to an assertion in the linker script. Map it RW and
1985 * the rest of .bss RO.
1986 */
1987 err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_start),
1988 kvm_ksym_ref(__hyp_bss_end), PAGE_HYP);
1989 if (err) {
1990 kvm_err("Cannot map hyp bss section: %d\n", err);
1991 goto out_err;
1992 }
1993
1994 err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_end),
1995 kvm_ksym_ref(__bss_stop), PAGE_HYP_RO);
1996 if (err) {
1997 kvm_err("Cannot map bss section\n");
1998 goto out_err;
1999 }
2000
2001 /*
2002 * Map the Hyp stack pages
2003 */
2004 for_each_possible_cpu(cpu) {
2005 struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
2006 char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
2007 unsigned long hyp_addr;
2008
2009 /*
2010 * Allocate a contiguous HYP private VA range for the stack
2011 * and guard page. The allocation is also aligned based on
2012 * the order of its size.
2013 */
2014 err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
2015 if (err) {
2016 kvm_err("Cannot allocate hyp stack guard page\n");
2017 goto out_err;
2018 }
2019
2020 /*
2021 * Since the stack grows downwards, map the stack to the page
2022 * at the higher address and leave the lower guard page
2023 * unbacked.
2024 *
2025 * Any valid stack address now has the PAGE_SHIFT bit as 1
2026 * and addresses corresponding to the guard page have the
2027 * PAGE_SHIFT bit as 0 - this is used for overflow detection.
2028 */
2029 err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE,
2030 __pa(stack_page), PAGE_HYP);
2031 if (err) {
2032 kvm_err("Cannot map hyp stack\n");
2033 goto out_err;
2034 }
2035
2036 /*
2037 * Save the stack PA in nvhe_init_params. This will be needed
2038 * to recreate the stack mapping in protected nVHE mode.
2039 * __hyp_pa() won't do the right thing there, since the stack
2040 * has been mapped in the flexible private VA space.
2041 */
2042 params->stack_pa = __pa(stack_page);
2043
2044 params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
2045 }
2046
2047 for_each_possible_cpu(cpu) {
2048 char *percpu_begin = (char *)kvm_arm_hyp_percpu_base[cpu];
2049 char *percpu_end = percpu_begin + nvhe_percpu_size();
2050
2051 /* Map Hyp percpu pages */
2052 err = create_hyp_mappings(percpu_begin, percpu_end, PAGE_HYP);
2053 if (err) {
2054 kvm_err("Cannot map hyp percpu region\n");
2055 goto out_err;
2056 }
2057
2058 /* Prepare the CPU initialization parameters */
2059 cpu_prepare_hyp_mode(cpu);
2060 }
2061
2062 if (is_protected_kvm_enabled()) {
2063 init_cpu_logical_map();
2064
2065 if (!init_psci_relay()) {
2066 err = -ENODEV;
2067 goto out_err;
2068 }
2069 }
2070
2071 if (is_protected_kvm_enabled()) {
2072 err = kvm_hyp_init_protection(hyp_va_bits);
2073 if (err) {
2074 kvm_err("Failed to init hyp memory protection\n");
2075 goto out_err;
2076 }
2077 }
2078
2079 return 0;
2080
2081 out_err:
2082 teardown_hyp_mode();
2083 kvm_err("error initializing Hyp mode: %d\n", err);
2084 return err;
2085 }
2086
_kvm_host_prot_finalize(void * arg)2087 static void _kvm_host_prot_finalize(void *arg)
2088 {
2089 int *err = arg;
2090
2091 if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))
2092 WRITE_ONCE(*err, -EINVAL);
2093 }
2094
pkvm_drop_host_privileges(void)2095 static int pkvm_drop_host_privileges(void)
2096 {
2097 int ret = 0;
2098
2099 /*
2100 * Flip the static key upfront as that may no longer be possible
2101 * once the host stage 2 is installed.
2102 */
2103 static_branch_enable(&kvm_protected_mode_initialized);
2104 on_each_cpu(_kvm_host_prot_finalize, &ret, 1);
2105 return ret;
2106 }
2107
finalize_hyp_mode(void)2108 static int finalize_hyp_mode(void)
2109 {
2110 if (!is_protected_kvm_enabled())
2111 return 0;
2112
2113 /*
2114 * Exclude HYP sections from kmemleak so that they don't get peeked
2115 * at, which would end badly once inaccessible.
2116 */
2117 kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
2118 kmemleak_free_part(__va(hyp_mem_base), hyp_mem_size);
2119 return pkvm_drop_host_privileges();
2120 }
2121
kvm_mpidr_to_vcpu(struct kvm * kvm,unsigned long mpidr)2122 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
2123 {
2124 struct kvm_vcpu *vcpu;
2125 unsigned long i;
2126
2127 mpidr &= MPIDR_HWID_BITMASK;
2128 kvm_for_each_vcpu(i, vcpu, kvm) {
2129 if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
2130 return vcpu;
2131 }
2132 return NULL;
2133 }
2134
kvm_arch_has_irq_bypass(void)2135 bool kvm_arch_has_irq_bypass(void)
2136 {
2137 return true;
2138 }
2139
kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer * cons,struct irq_bypass_producer * prod)2140 int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
2141 struct irq_bypass_producer *prod)
2142 {
2143 struct kvm_kernel_irqfd *irqfd =
2144 container_of(cons, struct kvm_kernel_irqfd, consumer);
2145
2146 return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
2147 &irqfd->irq_entry);
2148 }
kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer * cons,struct irq_bypass_producer * prod)2149 void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
2150 struct irq_bypass_producer *prod)
2151 {
2152 struct kvm_kernel_irqfd *irqfd =
2153 container_of(cons, struct kvm_kernel_irqfd, consumer);
2154
2155 kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
2156 &irqfd->irq_entry);
2157 }
2158
kvm_arch_irq_bypass_stop(struct irq_bypass_consumer * cons)2159 void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
2160 {
2161 struct kvm_kernel_irqfd *irqfd =
2162 container_of(cons, struct kvm_kernel_irqfd, consumer);
2163
2164 kvm_arm_halt_guest(irqfd->kvm);
2165 }
2166
kvm_arch_irq_bypass_start(struct irq_bypass_consumer * cons)2167 void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
2168 {
2169 struct kvm_kernel_irqfd *irqfd =
2170 container_of(cons, struct kvm_kernel_irqfd, consumer);
2171
2172 kvm_arm_resume_guest(irqfd->kvm);
2173 }
2174
2175 /**
2176 * Initialize Hyp-mode and memory mappings on all CPUs.
2177 */
kvm_arch_init(void * opaque)2178 int kvm_arch_init(void *opaque)
2179 {
2180 int err;
2181 bool in_hyp_mode;
2182
2183 if (!is_hyp_mode_available()) {
2184 kvm_info("HYP mode not available\n");
2185 return -ENODEV;
2186 }
2187
2188 if (kvm_get_mode() == KVM_MODE_NONE) {
2189 kvm_info("KVM disabled from command line\n");
2190 return -ENODEV;
2191 }
2192
2193 err = kvm_sys_reg_table_init();
2194 if (err) {
2195 kvm_info("Error initializing system register tables");
2196 return err;
2197 }
2198
2199 in_hyp_mode = is_kernel_in_hyp_mode();
2200
2201 if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
2202 cpus_have_final_cap(ARM64_WORKAROUND_1508412))
2203 kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
2204 "Only trusted guests should be used on this system.\n");
2205
2206 err = kvm_set_ipa_limit();
2207 if (err)
2208 return err;
2209
2210 err = kvm_arm_init_sve();
2211 if (err)
2212 return err;
2213
2214 err = kvm_arm_vmid_alloc_init();
2215 if (err) {
2216 kvm_err("Failed to initialize VMID allocator.\n");
2217 return err;
2218 }
2219
2220 if (!in_hyp_mode) {
2221 err = init_hyp_mode();
2222 if (err)
2223 goto out_err;
2224 }
2225
2226 err = kvm_init_vector_slots();
2227 if (err) {
2228 kvm_err("Cannot initialise vector slots\n");
2229 goto out_err;
2230 }
2231
2232 err = init_subsystems();
2233 if (err)
2234 goto out_hyp;
2235
2236 if (!in_hyp_mode) {
2237 err = finalize_hyp_mode();
2238 if (err) {
2239 kvm_err("Failed to finalize Hyp protection\n");
2240 goto out_hyp;
2241 }
2242 }
2243
2244 if (is_protected_kvm_enabled()) {
2245 kvm_info("Protected nVHE mode initialized successfully\n");
2246 } else if (in_hyp_mode) {
2247 kvm_info("VHE mode initialized successfully\n");
2248 } else {
2249 kvm_info("Hyp mode initialized successfully\n");
2250 }
2251
2252 return 0;
2253
2254 out_hyp:
2255 hyp_cpu_pm_exit();
2256 if (!in_hyp_mode)
2257 teardown_hyp_mode();
2258 out_err:
2259 kvm_arm_vmid_alloc_free();
2260 return err;
2261 }
2262
2263 /* NOP: Compiling as a module not supported */
kvm_arch_exit(void)2264 void kvm_arch_exit(void)
2265 {
2266 kvm_unregister_perf_callbacks();
2267 }
2268
early_kvm_mode_cfg(char * arg)2269 static int __init early_kvm_mode_cfg(char *arg)
2270 {
2271 if (!arg)
2272 return -EINVAL;
2273
2274 if (strcmp(arg, "protected") == 0) {
2275 if (!is_kernel_in_hyp_mode())
2276 kvm_mode = KVM_MODE_PROTECTED;
2277 else
2278 pr_warn_once("Protected KVM not available with VHE\n");
2279
2280 return 0;
2281 }
2282
2283 if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode())) {
2284 kvm_mode = KVM_MODE_DEFAULT;
2285 return 0;
2286 }
2287
2288 if (strcmp(arg, "none") == 0) {
2289 kvm_mode = KVM_MODE_NONE;
2290 return 0;
2291 }
2292
2293 return -EINVAL;
2294 }
2295 early_param("kvm-arm.mode", early_kvm_mode_cfg);
2296
kvm_get_mode(void)2297 enum kvm_mode kvm_get_mode(void)
2298 {
2299 return kvm_mode;
2300 }
2301
arm_init(void)2302 static int arm_init(void)
2303 {
2304 int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
2305 return rc;
2306 }
2307
2308 module_init(arm_init);
2309