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1 /*
2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License, version 2, as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17  */
18 
19 #include <linux/bug.h>
20 #include <linux/cpu_pm.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/kvm_host.h>
24 #include <linux/list.h>
25 #include <linux/module.h>
26 #include <linux/vmalloc.h>
27 #include <linux/fs.h>
28 #include <linux/mman.h>
29 #include <linux/sched.h>
30 #include <linux/kvm.h>
31 #include <linux/kvm_irqfd.h>
32 #include <linux/irqbypass.h>
33 #include <linux/sched/stat.h>
34 #include <trace/events/kvm.h>
35 #include <kvm/arm_pmu.h>
36 #include <kvm/arm_psci.h>
37 
38 #define CREATE_TRACE_POINTS
39 #include "trace.h"
40 
41 #include <linux/uaccess.h>
42 #include <asm/ptrace.h>
43 #include <asm/mman.h>
44 #include <asm/tlbflush.h>
45 #include <asm/cacheflush.h>
46 #include <asm/cpufeature.h>
47 #include <asm/virt.h>
48 #include <asm/kvm_arm.h>
49 #include <asm/kvm_asm.h>
50 #include <asm/kvm_mmu.h>
51 #include <asm/kvm_emulate.h>
52 #include <asm/kvm_coproc.h>
53 #include <asm/sections.h>
54 
55 #ifdef REQUIRES_VIRT
56 __asm__(".arch_extension	virt");
57 #endif
58 
59 DEFINE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state);
60 static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
61 
62 /* Per-CPU variable containing the currently running vcpu. */
63 static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_arm_running_vcpu);
64 
65 /* The VMID used in the VTTBR */
66 static atomic64_t kvm_vmid_gen = ATOMIC64_INIT(1);
67 static u32 kvm_next_vmid;
68 static unsigned int kvm_vmid_bits __read_mostly;
69 static DEFINE_SPINLOCK(kvm_vmid_lock);
70 
71 static bool vgic_present;
72 
73 static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
74 
kvm_arm_set_running_vcpu(struct kvm_vcpu * vcpu)75 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
76 {
77 	__this_cpu_write(kvm_arm_running_vcpu, vcpu);
78 }
79 
80 DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
81 
82 /**
83  * kvm_arm_get_running_vcpu - get the vcpu running on the current CPU.
84  * Must be called from non-preemptible context
85  */
kvm_arm_get_running_vcpu(void)86 struct kvm_vcpu *kvm_arm_get_running_vcpu(void)
87 {
88 	return __this_cpu_read(kvm_arm_running_vcpu);
89 }
90 
91 /**
92  * kvm_arm_get_running_vcpus - get the per-CPU array of currently running vcpus.
93  */
kvm_get_running_vcpus(void)94 struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
95 {
96 	return &kvm_arm_running_vcpu;
97 }
98 
kvm_arch_vcpu_should_kick(struct kvm_vcpu * vcpu)99 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
100 {
101 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
102 }
103 
kvm_arch_hardware_setup(void)104 int kvm_arch_hardware_setup(void)
105 {
106 	return 0;
107 }
108 
kvm_arch_check_processor_compat(void * rtn)109 void kvm_arch_check_processor_compat(void *rtn)
110 {
111 	*(int *)rtn = 0;
112 }
113 
114 
115 /**
116  * kvm_arch_init_vm - initializes a VM data structure
117  * @kvm:	pointer to the KVM struct
118  */
kvm_arch_init_vm(struct kvm * kvm,unsigned long type)119 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
120 {
121 	int ret, cpu;
122 
123 	if (type)
124 		return -EINVAL;
125 
126 	kvm->arch.last_vcpu_ran = alloc_percpu(typeof(*kvm->arch.last_vcpu_ran));
127 	if (!kvm->arch.last_vcpu_ran)
128 		return -ENOMEM;
129 
130 	for_each_possible_cpu(cpu)
131 		*per_cpu_ptr(kvm->arch.last_vcpu_ran, cpu) = -1;
132 
133 	ret = kvm_alloc_stage2_pgd(kvm);
134 	if (ret)
135 		goto out_fail_alloc;
136 
137 	ret = create_hyp_mappings(kvm, kvm + 1, PAGE_HYP);
138 	if (ret)
139 		goto out_free_stage2_pgd;
140 
141 	kvm_vgic_early_init(kvm);
142 
143 	/* Mark the initial VMID generation invalid */
144 	kvm->arch.vmid_gen = 0;
145 
146 	/* The maximum number of VCPUs is limited by the host's GIC model */
147 	kvm->arch.max_vcpus = vgic_present ?
148 				kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
149 
150 	return ret;
151 out_free_stage2_pgd:
152 	kvm_free_stage2_pgd(kvm);
153 out_fail_alloc:
154 	free_percpu(kvm->arch.last_vcpu_ran);
155 	kvm->arch.last_vcpu_ran = NULL;
156 	return ret;
157 }
158 
kvm_arch_has_vcpu_debugfs(void)159 bool kvm_arch_has_vcpu_debugfs(void)
160 {
161 	return false;
162 }
163 
kvm_arch_create_vcpu_debugfs(struct kvm_vcpu * vcpu)164 int kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
165 {
166 	return 0;
167 }
168 
kvm_arch_vcpu_fault(struct kvm_vcpu * vcpu,struct vm_fault * vmf)169 vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
170 {
171 	return VM_FAULT_SIGBUS;
172 }
173 
174 
175 /**
176  * kvm_arch_destroy_vm - destroy the VM data structure
177  * @kvm:	pointer to the KVM struct
178  */
kvm_arch_destroy_vm(struct kvm * kvm)179 void kvm_arch_destroy_vm(struct kvm *kvm)
180 {
181 	int i;
182 
183 	kvm_vgic_destroy(kvm);
184 
185 	free_percpu(kvm->arch.last_vcpu_ran);
186 	kvm->arch.last_vcpu_ran = NULL;
187 
188 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
189 		if (kvm->vcpus[i]) {
190 			kvm_arch_vcpu_free(kvm->vcpus[i]);
191 			kvm->vcpus[i] = NULL;
192 		}
193 	}
194 	atomic_set(&kvm->online_vcpus, 0);
195 }
196 
kvm_vm_ioctl_check_extension(struct kvm * kvm,long ext)197 int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
198 {
199 	int r;
200 	switch (ext) {
201 	case KVM_CAP_IRQCHIP:
202 		r = vgic_present;
203 		break;
204 	case KVM_CAP_IOEVENTFD:
205 	case KVM_CAP_DEVICE_CTRL:
206 	case KVM_CAP_USER_MEMORY:
207 	case KVM_CAP_SYNC_MMU:
208 	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
209 	case KVM_CAP_ONE_REG:
210 	case KVM_CAP_ARM_PSCI:
211 	case KVM_CAP_ARM_PSCI_0_2:
212 	case KVM_CAP_READONLY_MEM:
213 	case KVM_CAP_MP_STATE:
214 	case KVM_CAP_IMMEDIATE_EXIT:
215 		r = 1;
216 		break;
217 	case KVM_CAP_ARM_SET_DEVICE_ADDR:
218 		r = 1;
219 		break;
220 	case KVM_CAP_NR_VCPUS:
221 		r = num_online_cpus();
222 		break;
223 	case KVM_CAP_MAX_VCPUS:
224 		r = KVM_MAX_VCPUS;
225 		break;
226 	case KVM_CAP_MAX_VCPU_ID:
227 		r = KVM_MAX_VCPU_ID;
228 		break;
229 	case KVM_CAP_NR_MEMSLOTS:
230 		r = KVM_USER_MEM_SLOTS;
231 		break;
232 	case KVM_CAP_MSI_DEVID:
233 		if (!kvm)
234 			r = -EINVAL;
235 		else
236 			r = kvm->arch.vgic.msis_require_devid;
237 		break;
238 	case KVM_CAP_ARM_USER_IRQ:
239 		/*
240 		 * 1: EL1_VTIMER, EL1_PTIMER, and PMU.
241 		 * (bump this number if adding more devices)
242 		 */
243 		r = 1;
244 		break;
245 	default:
246 		r = kvm_arch_dev_ioctl_check_extension(kvm, ext);
247 		break;
248 	}
249 	return r;
250 }
251 
kvm_arch_dev_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)252 long kvm_arch_dev_ioctl(struct file *filp,
253 			unsigned int ioctl, unsigned long arg)
254 {
255 	return -EINVAL;
256 }
257 
kvm_arch_alloc_vm(void)258 struct kvm *kvm_arch_alloc_vm(void)
259 {
260 	if (!has_vhe())
261 		return kzalloc(sizeof(struct kvm), GFP_KERNEL);
262 
263 	return vzalloc(sizeof(struct kvm));
264 }
265 
kvm_arch_free_vm(struct kvm * kvm)266 void kvm_arch_free_vm(struct kvm *kvm)
267 {
268 	if (!has_vhe())
269 		kfree(kvm);
270 	else
271 		vfree(kvm);
272 }
273 
kvm_arch_vcpu_create(struct kvm * kvm,unsigned int id)274 struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
275 {
276 	int err;
277 	struct kvm_vcpu *vcpu;
278 
279 	if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) {
280 		err = -EBUSY;
281 		goto out;
282 	}
283 
284 	if (id >= kvm->arch.max_vcpus) {
285 		err = -EINVAL;
286 		goto out;
287 	}
288 
289 	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
290 	if (!vcpu) {
291 		err = -ENOMEM;
292 		goto out;
293 	}
294 
295 	err = kvm_vcpu_init(vcpu, kvm, id);
296 	if (err)
297 		goto free_vcpu;
298 
299 	err = create_hyp_mappings(vcpu, vcpu + 1, PAGE_HYP);
300 	if (err)
301 		goto vcpu_uninit;
302 
303 	return vcpu;
304 vcpu_uninit:
305 	kvm_vcpu_uninit(vcpu);
306 free_vcpu:
307 	kmem_cache_free(kvm_vcpu_cache, vcpu);
308 out:
309 	return ERR_PTR(err);
310 }
311 
kvm_arch_vcpu_postcreate(struct kvm_vcpu * vcpu)312 void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
313 {
314 }
315 
kvm_arch_vcpu_free(struct kvm_vcpu * vcpu)316 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
317 {
318 	if (vcpu->arch.has_run_once && unlikely(!irqchip_in_kernel(vcpu->kvm)))
319 		static_branch_dec(&userspace_irqchip_in_use);
320 
321 	kvm_mmu_free_memory_caches(vcpu);
322 	kvm_timer_vcpu_terminate(vcpu);
323 	kvm_pmu_vcpu_destroy(vcpu);
324 	kvm_vcpu_uninit(vcpu);
325 	kmem_cache_free(kvm_vcpu_cache, vcpu);
326 }
327 
kvm_arch_vcpu_destroy(struct kvm_vcpu * vcpu)328 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
329 {
330 	kvm_arch_vcpu_free(vcpu);
331 }
332 
kvm_cpu_has_pending_timer(struct kvm_vcpu * vcpu)333 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
334 {
335 	return kvm_timer_is_pending(vcpu);
336 }
337 
kvm_arch_vcpu_blocking(struct kvm_vcpu * vcpu)338 void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
339 {
340 	kvm_timer_schedule(vcpu);
341 	/*
342 	 * If we're about to block (most likely because we've just hit a
343 	 * WFI), we need to sync back the state of the GIC CPU interface
344 	 * so that we have the lastest PMR and group enables. This ensures
345 	 * that kvm_arch_vcpu_runnable has up-to-date data to decide
346 	 * whether we have pending interrupts.
347 	 */
348 	preempt_disable();
349 	kvm_vgic_vmcr_sync(vcpu);
350 	preempt_enable();
351 
352 	kvm_vgic_v4_enable_doorbell(vcpu);
353 }
354 
kvm_arch_vcpu_unblocking(struct kvm_vcpu * vcpu)355 void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
356 {
357 	kvm_timer_unschedule(vcpu);
358 	kvm_vgic_v4_disable_doorbell(vcpu);
359 }
360 
kvm_arch_vcpu_init(struct kvm_vcpu * vcpu)361 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
362 {
363 	/* Force users to call KVM_ARM_VCPU_INIT */
364 	vcpu->arch.target = -1;
365 	bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
366 
367 	/* Set up the timer */
368 	kvm_timer_vcpu_init(vcpu);
369 
370 	kvm_arm_reset_debug_ptr(vcpu);
371 
372 	return kvm_vgic_vcpu_init(vcpu);
373 }
374 
kvm_arch_vcpu_load(struct kvm_vcpu * vcpu,int cpu)375 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
376 {
377 	int *last_ran;
378 
379 	last_ran = this_cpu_ptr(vcpu->kvm->arch.last_vcpu_ran);
380 
381 	/*
382 	 * We might get preempted before the vCPU actually runs, but
383 	 * over-invalidation doesn't affect correctness.
384 	 */
385 	if (*last_ran != vcpu->vcpu_id) {
386 		kvm_call_hyp(__kvm_tlb_flush_local_vmid, vcpu);
387 		*last_ran = vcpu->vcpu_id;
388 	}
389 
390 	vcpu->cpu = cpu;
391 	vcpu->arch.host_cpu_context = this_cpu_ptr(&kvm_host_cpu_state);
392 
393 	kvm_arm_set_running_vcpu(vcpu);
394 	kvm_vgic_load(vcpu);
395 	kvm_timer_vcpu_load(vcpu);
396 	kvm_vcpu_load_sysregs(vcpu);
397 	kvm_arch_vcpu_load_fp(vcpu);
398 
399 	if (single_task_running())
400 		vcpu_clear_wfe_traps(vcpu);
401 	else
402 		vcpu_set_wfe_traps(vcpu);
403 }
404 
kvm_arch_vcpu_put(struct kvm_vcpu * vcpu)405 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
406 {
407 	kvm_arch_vcpu_put_fp(vcpu);
408 	kvm_vcpu_put_sysregs(vcpu);
409 	kvm_timer_vcpu_put(vcpu);
410 	kvm_vgic_put(vcpu);
411 
412 	vcpu->cpu = -1;
413 
414 	kvm_arm_set_running_vcpu(NULL);
415 }
416 
vcpu_power_off(struct kvm_vcpu * vcpu)417 static void vcpu_power_off(struct kvm_vcpu *vcpu)
418 {
419 	vcpu->arch.power_off = true;
420 	kvm_make_request(KVM_REQ_SLEEP, vcpu);
421 	kvm_vcpu_kick(vcpu);
422 }
423 
kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)424 int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
425 				    struct kvm_mp_state *mp_state)
426 {
427 	if (vcpu->arch.power_off)
428 		mp_state->mp_state = KVM_MP_STATE_STOPPED;
429 	else
430 		mp_state->mp_state = KVM_MP_STATE_RUNNABLE;
431 
432 	return 0;
433 }
434 
kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu * vcpu,struct kvm_mp_state * mp_state)435 int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
436 				    struct kvm_mp_state *mp_state)
437 {
438 	int ret = 0;
439 
440 	switch (mp_state->mp_state) {
441 	case KVM_MP_STATE_RUNNABLE:
442 		vcpu->arch.power_off = false;
443 		break;
444 	case KVM_MP_STATE_STOPPED:
445 		vcpu_power_off(vcpu);
446 		break;
447 	default:
448 		ret = -EINVAL;
449 	}
450 
451 	return ret;
452 }
453 
454 /**
455  * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
456  * @v:		The VCPU pointer
457  *
458  * If the guest CPU is not waiting for interrupts or an interrupt line is
459  * asserted, the CPU is by definition runnable.
460  */
kvm_arch_vcpu_runnable(struct kvm_vcpu * v)461 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
462 {
463 	bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
464 	return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
465 		&& !v->arch.power_off && !v->arch.pause);
466 }
467 
kvm_arch_vcpu_in_kernel(struct kvm_vcpu * vcpu)468 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
469 {
470 	return vcpu_mode_priv(vcpu);
471 }
472 
473 /* Just ensure a guest exit from a particular CPU */
exit_vm_noop(void * info)474 static void exit_vm_noop(void *info)
475 {
476 }
477 
force_vm_exit(const cpumask_t * mask)478 void force_vm_exit(const cpumask_t *mask)
479 {
480 	preempt_disable();
481 	smp_call_function_many(mask, exit_vm_noop, NULL, true);
482 	preempt_enable();
483 }
484 
485 /**
486  * need_new_vmid_gen - check that the VMID is still valid
487  * @kvm: The VM's VMID to check
488  *
489  * return true if there is a new generation of VMIDs being used
490  *
491  * The hardware supports only 256 values with the value zero reserved for the
492  * host, so we check if an assigned value belongs to a previous generation,
493  * which which requires us to assign a new value. If we're the first to use a
494  * VMID for the new generation, we must flush necessary caches and TLBs on all
495  * CPUs.
496  */
need_new_vmid_gen(struct kvm * kvm)497 static bool need_new_vmid_gen(struct kvm *kvm)
498 {
499 	u64 current_vmid_gen = atomic64_read(&kvm_vmid_gen);
500 	smp_rmb(); /* Orders read of kvm_vmid_gen and kvm->arch.vmid */
501 	return unlikely(READ_ONCE(kvm->arch.vmid_gen) != current_vmid_gen);
502 }
503 
504 /**
505  * update_vttbr - Update the VTTBR with a valid VMID before the guest runs
506  * @kvm	The guest that we are about to run
507  *
508  * Called from kvm_arch_vcpu_ioctl_run before entering the guest to ensure the
509  * VM has a valid VMID, otherwise assigns a new one and flushes corresponding
510  * caches and TLBs.
511  */
update_vttbr(struct kvm * kvm)512 static void update_vttbr(struct kvm *kvm)
513 {
514 	phys_addr_t pgd_phys;
515 	u64 vmid;
516 
517 	if (!need_new_vmid_gen(kvm))
518 		return;
519 
520 	spin_lock(&kvm_vmid_lock);
521 
522 	/*
523 	 * We need to re-check the vmid_gen here to ensure that if another vcpu
524 	 * already allocated a valid vmid for this vm, then this vcpu should
525 	 * use the same vmid.
526 	 */
527 	if (!need_new_vmid_gen(kvm)) {
528 		spin_unlock(&kvm_vmid_lock);
529 		return;
530 	}
531 
532 	/* First user of a new VMID generation? */
533 	if (unlikely(kvm_next_vmid == 0)) {
534 		atomic64_inc(&kvm_vmid_gen);
535 		kvm_next_vmid = 1;
536 
537 		/*
538 		 * On SMP we know no other CPUs can use this CPU's or each
539 		 * other's VMID after force_vm_exit returns since the
540 		 * kvm_vmid_lock blocks them from reentry to the guest.
541 		 */
542 		force_vm_exit(cpu_all_mask);
543 		/*
544 		 * Now broadcast TLB + ICACHE invalidation over the inner
545 		 * shareable domain to make sure all data structures are
546 		 * clean.
547 		 */
548 		kvm_call_hyp(__kvm_flush_vm_context);
549 	}
550 
551 	kvm->arch.vmid = kvm_next_vmid;
552 	kvm_next_vmid++;
553 	kvm_next_vmid &= (1 << kvm_vmid_bits) - 1;
554 
555 	/* update vttbr to be used with the new vmid */
556 	pgd_phys = virt_to_phys(kvm->arch.pgd);
557 	BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK);
558 	vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK(kvm_vmid_bits);
559 	kvm->arch.vttbr = kvm_phys_to_vttbr(pgd_phys) | vmid;
560 
561 	smp_wmb();
562 	WRITE_ONCE(kvm->arch.vmid_gen, atomic64_read(&kvm_vmid_gen));
563 
564 	spin_unlock(&kvm_vmid_lock);
565 }
566 
kvm_vcpu_first_run_init(struct kvm_vcpu * vcpu)567 static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
568 {
569 	struct kvm *kvm = vcpu->kvm;
570 	int ret = 0;
571 
572 	if (likely(vcpu->arch.has_run_once))
573 		return 0;
574 
575 	vcpu->arch.has_run_once = true;
576 
577 	if (likely(irqchip_in_kernel(kvm))) {
578 		/*
579 		 * Map the VGIC hardware resources before running a vcpu the
580 		 * first time on this VM.
581 		 */
582 		if (unlikely(!vgic_ready(kvm))) {
583 			ret = kvm_vgic_map_resources(kvm);
584 			if (ret)
585 				return ret;
586 		}
587 	} else {
588 		/*
589 		 * Tell the rest of the code that there are userspace irqchip
590 		 * VMs in the wild.
591 		 */
592 		static_branch_inc(&userspace_irqchip_in_use);
593 	}
594 
595 	ret = kvm_timer_enable(vcpu);
596 	if (ret)
597 		return ret;
598 
599 	ret = kvm_arm_pmu_v3_enable(vcpu);
600 
601 	return ret;
602 }
603 
kvm_arch_intc_initialized(struct kvm * kvm)604 bool kvm_arch_intc_initialized(struct kvm *kvm)
605 {
606 	return vgic_initialized(kvm);
607 }
608 
kvm_arm_halt_guest(struct kvm * kvm)609 void kvm_arm_halt_guest(struct kvm *kvm)
610 {
611 	int i;
612 	struct kvm_vcpu *vcpu;
613 
614 	kvm_for_each_vcpu(i, vcpu, kvm)
615 		vcpu->arch.pause = true;
616 	kvm_make_all_cpus_request(kvm, KVM_REQ_SLEEP);
617 }
618 
kvm_arm_resume_guest(struct kvm * kvm)619 void kvm_arm_resume_guest(struct kvm *kvm)
620 {
621 	int i;
622 	struct kvm_vcpu *vcpu;
623 
624 	kvm_for_each_vcpu(i, vcpu, kvm) {
625 		vcpu->arch.pause = false;
626 		swake_up_one(kvm_arch_vcpu_wq(vcpu));
627 	}
628 }
629 
vcpu_req_sleep(struct kvm_vcpu * vcpu)630 static void vcpu_req_sleep(struct kvm_vcpu *vcpu)
631 {
632 	struct swait_queue_head *wq = kvm_arch_vcpu_wq(vcpu);
633 
634 	swait_event_interruptible_exclusive(*wq, ((!vcpu->arch.power_off) &&
635 				       (!vcpu->arch.pause)));
636 
637 	if (vcpu->arch.power_off || vcpu->arch.pause) {
638 		/* Awaken to handle a signal, request we sleep again later. */
639 		kvm_make_request(KVM_REQ_SLEEP, vcpu);
640 	}
641 
642 	/*
643 	 * Make sure we will observe a potential reset request if we've
644 	 * observed a change to the power state. Pairs with the smp_wmb() in
645 	 * kvm_psci_vcpu_on().
646 	 */
647 	smp_rmb();
648 }
649 
kvm_vcpu_initialized(struct kvm_vcpu * vcpu)650 static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
651 {
652 	return vcpu->arch.target >= 0;
653 }
654 
check_vcpu_requests(struct kvm_vcpu * vcpu)655 static void check_vcpu_requests(struct kvm_vcpu *vcpu)
656 {
657 	if (kvm_request_pending(vcpu)) {
658 		if (kvm_check_request(KVM_REQ_SLEEP, vcpu))
659 			vcpu_req_sleep(vcpu);
660 
661 		if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
662 			kvm_reset_vcpu(vcpu);
663 
664 		/*
665 		 * Clear IRQ_PENDING requests that were made to guarantee
666 		 * that a VCPU sees new virtual interrupts.
667 		 */
668 		kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);
669 	}
670 }
671 
672 /**
673  * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
674  * @vcpu:	The VCPU pointer
675  * @run:	The kvm_run structure pointer used for userspace state exchange
676  *
677  * This function is called through the VCPU_RUN ioctl called from user space. It
678  * will execute VM code in a loop until the time slice for the process is used
679  * or some emulation is needed from user space in which case the function will
680  * return with return value 0 and with the kvm_run structure filled in with the
681  * required data for the requested emulation.
682  */
kvm_arch_vcpu_ioctl_run(struct kvm_vcpu * vcpu,struct kvm_run * run)683 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
684 {
685 	int ret;
686 
687 	if (unlikely(!kvm_vcpu_initialized(vcpu)))
688 		return -ENOEXEC;
689 
690 	ret = kvm_vcpu_first_run_init(vcpu);
691 	if (ret)
692 		return ret;
693 
694 	if (run->exit_reason == KVM_EXIT_MMIO) {
695 		ret = kvm_handle_mmio_return(vcpu, vcpu->run);
696 		if (ret)
697 			return ret;
698 		if (kvm_arm_handle_step_debug(vcpu, vcpu->run))
699 			return 0;
700 	}
701 
702 	if (run->immediate_exit)
703 		return -EINTR;
704 
705 	vcpu_load(vcpu);
706 
707 	kvm_sigset_activate(vcpu);
708 
709 	ret = 1;
710 	run->exit_reason = KVM_EXIT_UNKNOWN;
711 	while (ret > 0) {
712 		/*
713 		 * Check conditions before entering the guest
714 		 */
715 		cond_resched();
716 
717 		update_vttbr(vcpu->kvm);
718 
719 		check_vcpu_requests(vcpu);
720 
721 		/*
722 		 * Preparing the interrupts to be injected also
723 		 * involves poking the GIC, which must be done in a
724 		 * non-preemptible context.
725 		 */
726 		preempt_disable();
727 
728 		kvm_pmu_flush_hwstate(vcpu);
729 
730 		local_irq_disable();
731 
732 		kvm_vgic_flush_hwstate(vcpu);
733 
734 		/*
735 		 * Exit if we have a signal pending so that we can deliver the
736 		 * signal to user space.
737 		 */
738 		if (signal_pending(current)) {
739 			ret = -EINTR;
740 			run->exit_reason = KVM_EXIT_INTR;
741 		}
742 
743 		/*
744 		 * If we're using a userspace irqchip, then check if we need
745 		 * to tell a userspace irqchip about timer or PMU level
746 		 * changes and if so, exit to userspace (the actual level
747 		 * state gets updated in kvm_timer_update_run and
748 		 * kvm_pmu_update_run below).
749 		 */
750 		if (static_branch_unlikely(&userspace_irqchip_in_use)) {
751 			if (kvm_timer_should_notify_user(vcpu) ||
752 			    kvm_pmu_should_notify_user(vcpu)) {
753 				ret = -EINTR;
754 				run->exit_reason = KVM_EXIT_INTR;
755 			}
756 		}
757 
758 		/*
759 		 * Ensure we set mode to IN_GUEST_MODE after we disable
760 		 * interrupts and before the final VCPU requests check.
761 		 * See the comment in kvm_vcpu_exiting_guest_mode() and
762 		 * Documentation/virtual/kvm/vcpu-requests.rst
763 		 */
764 		smp_store_mb(vcpu->mode, IN_GUEST_MODE);
765 
766 		if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) ||
767 		    kvm_request_pending(vcpu)) {
768 			vcpu->mode = OUTSIDE_GUEST_MODE;
769 			isb(); /* Ensure work in x_flush_hwstate is committed */
770 			kvm_pmu_sync_hwstate(vcpu);
771 			if (static_branch_unlikely(&userspace_irqchip_in_use))
772 				kvm_timer_sync_hwstate(vcpu);
773 			kvm_vgic_sync_hwstate(vcpu);
774 			local_irq_enable();
775 			preempt_enable();
776 			continue;
777 		}
778 
779 		kvm_arm_setup_debug(vcpu);
780 
781 		/**************************************************************
782 		 * Enter the guest
783 		 */
784 		trace_kvm_entry(*vcpu_pc(vcpu));
785 		guest_enter_irqoff();
786 
787 		if (has_vhe()) {
788 			kvm_arm_vhe_guest_enter();
789 			ret = kvm_vcpu_run_vhe(vcpu);
790 			kvm_arm_vhe_guest_exit();
791 		} else {
792 			ret = kvm_call_hyp(__kvm_vcpu_run_nvhe, vcpu);
793 		}
794 
795 		vcpu->mode = OUTSIDE_GUEST_MODE;
796 		vcpu->stat.exits++;
797 		/*
798 		 * Back from guest
799 		 *************************************************************/
800 
801 		kvm_arm_clear_debug(vcpu);
802 
803 		/*
804 		 * We must sync the PMU state before the vgic state so
805 		 * that the vgic can properly sample the updated state of the
806 		 * interrupt line.
807 		 */
808 		kvm_pmu_sync_hwstate(vcpu);
809 
810 		/*
811 		 * Sync the vgic state before syncing the timer state because
812 		 * the timer code needs to know if the virtual timer
813 		 * interrupts are active.
814 		 */
815 		kvm_vgic_sync_hwstate(vcpu);
816 
817 		/*
818 		 * Sync the timer hardware state before enabling interrupts as
819 		 * we don't want vtimer interrupts to race with syncing the
820 		 * timer virtual interrupt state.
821 		 */
822 		if (static_branch_unlikely(&userspace_irqchip_in_use))
823 			kvm_timer_sync_hwstate(vcpu);
824 
825 		kvm_arch_vcpu_ctxsync_fp(vcpu);
826 
827 		/*
828 		 * We may have taken a host interrupt in HYP mode (ie
829 		 * while executing the guest). This interrupt is still
830 		 * pending, as we haven't serviced it yet!
831 		 *
832 		 * We're now back in SVC mode, with interrupts
833 		 * disabled.  Enabling the interrupts now will have
834 		 * the effect of taking the interrupt again, in SVC
835 		 * mode this time.
836 		 */
837 		local_irq_enable();
838 
839 		/*
840 		 * We do local_irq_enable() before calling guest_exit() so
841 		 * that if a timer interrupt hits while running the guest we
842 		 * account that tick as being spent in the guest.  We enable
843 		 * preemption after calling guest_exit() so that if we get
844 		 * preempted we make sure ticks after that is not counted as
845 		 * guest time.
846 		 */
847 		guest_exit();
848 		trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
849 
850 		/* Exit types that need handling before we can be preempted */
851 		handle_exit_early(vcpu, run, ret);
852 
853 		preempt_enable();
854 
855 		ret = handle_exit(vcpu, run, ret);
856 	}
857 
858 	/* Tell userspace about in-kernel device output levels */
859 	if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
860 		kvm_timer_update_run(vcpu);
861 		kvm_pmu_update_run(vcpu);
862 	}
863 
864 	kvm_sigset_deactivate(vcpu);
865 
866 	vcpu_put(vcpu);
867 	return ret;
868 }
869 
vcpu_interrupt_line(struct kvm_vcpu * vcpu,int number,bool level)870 static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
871 {
872 	int bit_index;
873 	bool set;
874 	unsigned long *hcr;
875 
876 	if (number == KVM_ARM_IRQ_CPU_IRQ)
877 		bit_index = __ffs(HCR_VI);
878 	else /* KVM_ARM_IRQ_CPU_FIQ */
879 		bit_index = __ffs(HCR_VF);
880 
881 	hcr = vcpu_hcr(vcpu);
882 	if (level)
883 		set = test_and_set_bit(bit_index, hcr);
884 	else
885 		set = test_and_clear_bit(bit_index, hcr);
886 
887 	/*
888 	 * If we didn't change anything, no need to wake up or kick other CPUs
889 	 */
890 	if (set == level)
891 		return 0;
892 
893 	/*
894 	 * The vcpu irq_lines field was updated, wake up sleeping VCPUs and
895 	 * trigger a world-switch round on the running physical CPU to set the
896 	 * virtual IRQ/FIQ fields in the HCR appropriately.
897 	 */
898 	kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
899 	kvm_vcpu_kick(vcpu);
900 
901 	return 0;
902 }
903 
kvm_vm_ioctl_irq_line(struct kvm * kvm,struct kvm_irq_level * irq_level,bool line_status)904 int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
905 			  bool line_status)
906 {
907 	u32 irq = irq_level->irq;
908 	unsigned int irq_type, vcpu_idx, irq_num;
909 	int nrcpus = atomic_read(&kvm->online_vcpus);
910 	struct kvm_vcpu *vcpu = NULL;
911 	bool level = irq_level->level;
912 
913 	irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
914 	vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
915 	irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;
916 
917 	trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level);
918 
919 	switch (irq_type) {
920 	case KVM_ARM_IRQ_TYPE_CPU:
921 		if (irqchip_in_kernel(kvm))
922 			return -ENXIO;
923 
924 		if (vcpu_idx >= nrcpus)
925 			return -EINVAL;
926 
927 		vcpu = kvm_get_vcpu(kvm, vcpu_idx);
928 		if (!vcpu)
929 			return -EINVAL;
930 
931 		if (irq_num > KVM_ARM_IRQ_CPU_FIQ)
932 			return -EINVAL;
933 
934 		return vcpu_interrupt_line(vcpu, irq_num, level);
935 	case KVM_ARM_IRQ_TYPE_PPI:
936 		if (!irqchip_in_kernel(kvm))
937 			return -ENXIO;
938 
939 		if (vcpu_idx >= nrcpus)
940 			return -EINVAL;
941 
942 		vcpu = kvm_get_vcpu(kvm, vcpu_idx);
943 		if (!vcpu)
944 			return -EINVAL;
945 
946 		if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
947 			return -EINVAL;
948 
949 		return kvm_vgic_inject_irq(kvm, vcpu->vcpu_id, irq_num, level, NULL);
950 	case KVM_ARM_IRQ_TYPE_SPI:
951 		if (!irqchip_in_kernel(kvm))
952 			return -ENXIO;
953 
954 		if (irq_num < VGIC_NR_PRIVATE_IRQS)
955 			return -EINVAL;
956 
957 		return kvm_vgic_inject_irq(kvm, 0, irq_num, level, NULL);
958 	}
959 
960 	return -EINVAL;
961 }
962 
kvm_vcpu_set_target(struct kvm_vcpu * vcpu,const struct kvm_vcpu_init * init)963 static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
964 			       const struct kvm_vcpu_init *init)
965 {
966 	unsigned int i, ret;
967 	int phys_target = kvm_target_cpu();
968 
969 	if (init->target != phys_target)
970 		return -EINVAL;
971 
972 	/*
973 	 * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
974 	 * use the same target.
975 	 */
976 	if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
977 		return -EINVAL;
978 
979 	/* -ENOENT for unknown features, -EINVAL for invalid combinations. */
980 	for (i = 0; i < sizeof(init->features) * 8; i++) {
981 		bool set = (init->features[i / 32] & (1 << (i % 32)));
982 
983 		if (set && i >= KVM_VCPU_MAX_FEATURES)
984 			return -ENOENT;
985 
986 		/*
987 		 * Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
988 		 * use the same feature set.
989 		 */
990 		if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
991 		    test_bit(i, vcpu->arch.features) != set)
992 			return -EINVAL;
993 
994 		if (set)
995 			set_bit(i, vcpu->arch.features);
996 	}
997 
998 	vcpu->arch.target = phys_target;
999 
1000 	/* Now we know what it is, we can reset it. */
1001 	ret = kvm_reset_vcpu(vcpu);
1002 	if (ret) {
1003 		vcpu->arch.target = -1;
1004 		bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
1005 	}
1006 
1007 	return ret;
1008 }
1009 
kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu * vcpu,struct kvm_vcpu_init * init)1010 static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
1011 					 struct kvm_vcpu_init *init)
1012 {
1013 	int ret;
1014 
1015 	ret = kvm_vcpu_set_target(vcpu, init);
1016 	if (ret)
1017 		return ret;
1018 
1019 	/*
1020 	 * Ensure a rebooted VM will fault in RAM pages and detect if the
1021 	 * guest MMU is turned off and flush the caches as needed.
1022 	 */
1023 	if (vcpu->arch.has_run_once)
1024 		stage2_unmap_vm(vcpu->kvm);
1025 
1026 	vcpu_reset_hcr(vcpu);
1027 
1028 	/*
1029 	 * Handle the "start in power-off" case.
1030 	 */
1031 	if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
1032 		vcpu_power_off(vcpu);
1033 	else
1034 		vcpu->arch.power_off = false;
1035 
1036 	return 0;
1037 }
1038 
kvm_arm_vcpu_set_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1039 static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
1040 				 struct kvm_device_attr *attr)
1041 {
1042 	int ret = -ENXIO;
1043 
1044 	switch (attr->group) {
1045 	default:
1046 		ret = kvm_arm_vcpu_arch_set_attr(vcpu, attr);
1047 		break;
1048 	}
1049 
1050 	return ret;
1051 }
1052 
kvm_arm_vcpu_get_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1053 static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
1054 				 struct kvm_device_attr *attr)
1055 {
1056 	int ret = -ENXIO;
1057 
1058 	switch (attr->group) {
1059 	default:
1060 		ret = kvm_arm_vcpu_arch_get_attr(vcpu, attr);
1061 		break;
1062 	}
1063 
1064 	return ret;
1065 }
1066 
kvm_arm_vcpu_has_attr(struct kvm_vcpu * vcpu,struct kvm_device_attr * attr)1067 static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
1068 				 struct kvm_device_attr *attr)
1069 {
1070 	int ret = -ENXIO;
1071 
1072 	switch (attr->group) {
1073 	default:
1074 		ret = kvm_arm_vcpu_arch_has_attr(vcpu, attr);
1075 		break;
1076 	}
1077 
1078 	return ret;
1079 }
1080 
kvm_arm_vcpu_get_events(struct kvm_vcpu * vcpu,struct kvm_vcpu_events * events)1081 static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
1082 				   struct kvm_vcpu_events *events)
1083 {
1084 	memset(events, 0, sizeof(*events));
1085 
1086 	return __kvm_arm_vcpu_get_events(vcpu, events);
1087 }
1088 
kvm_arm_vcpu_set_events(struct kvm_vcpu * vcpu,struct kvm_vcpu_events * events)1089 static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
1090 				   struct kvm_vcpu_events *events)
1091 {
1092 	int i;
1093 
1094 	/* check whether the reserved field is zero */
1095 	for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
1096 		if (events->reserved[i])
1097 			return -EINVAL;
1098 
1099 	/* check whether the pad field is zero */
1100 	for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
1101 		if (events->exception.pad[i])
1102 			return -EINVAL;
1103 
1104 	return __kvm_arm_vcpu_set_events(vcpu, events);
1105 }
1106 
kvm_arch_vcpu_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)1107 long kvm_arch_vcpu_ioctl(struct file *filp,
1108 			 unsigned int ioctl, unsigned long arg)
1109 {
1110 	struct kvm_vcpu *vcpu = filp->private_data;
1111 	void __user *argp = (void __user *)arg;
1112 	struct kvm_device_attr attr;
1113 	long r;
1114 
1115 	switch (ioctl) {
1116 	case KVM_ARM_VCPU_INIT: {
1117 		struct kvm_vcpu_init init;
1118 
1119 		r = -EFAULT;
1120 		if (copy_from_user(&init, argp, sizeof(init)))
1121 			break;
1122 
1123 		r = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init);
1124 		break;
1125 	}
1126 	case KVM_SET_ONE_REG:
1127 	case KVM_GET_ONE_REG: {
1128 		struct kvm_one_reg reg;
1129 
1130 		r = -ENOEXEC;
1131 		if (unlikely(!kvm_vcpu_initialized(vcpu)))
1132 			break;
1133 
1134 		r = -EFAULT;
1135 		if (copy_from_user(&reg, argp, sizeof(reg)))
1136 			break;
1137 
1138 		if (ioctl == KVM_SET_ONE_REG)
1139 			r = kvm_arm_set_reg(vcpu, &reg);
1140 		else
1141 			r = kvm_arm_get_reg(vcpu, &reg);
1142 		break;
1143 	}
1144 	case KVM_GET_REG_LIST: {
1145 		struct kvm_reg_list __user *user_list = argp;
1146 		struct kvm_reg_list reg_list;
1147 		unsigned n;
1148 
1149 		r = -ENOEXEC;
1150 		if (unlikely(!kvm_vcpu_initialized(vcpu)))
1151 			break;
1152 
1153 		r = -EFAULT;
1154 		if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
1155 			break;
1156 		n = reg_list.n;
1157 		reg_list.n = kvm_arm_num_regs(vcpu);
1158 		if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
1159 			break;
1160 		r = -E2BIG;
1161 		if (n < reg_list.n)
1162 			break;
1163 		r = kvm_arm_copy_reg_indices(vcpu, user_list->reg);
1164 		break;
1165 	}
1166 	case KVM_SET_DEVICE_ATTR: {
1167 		r = -EFAULT;
1168 		if (copy_from_user(&attr, argp, sizeof(attr)))
1169 			break;
1170 		r = kvm_arm_vcpu_set_attr(vcpu, &attr);
1171 		break;
1172 	}
1173 	case KVM_GET_DEVICE_ATTR: {
1174 		r = -EFAULT;
1175 		if (copy_from_user(&attr, argp, sizeof(attr)))
1176 			break;
1177 		r = kvm_arm_vcpu_get_attr(vcpu, &attr);
1178 		break;
1179 	}
1180 	case KVM_HAS_DEVICE_ATTR: {
1181 		r = -EFAULT;
1182 		if (copy_from_user(&attr, argp, sizeof(attr)))
1183 			break;
1184 		r = kvm_arm_vcpu_has_attr(vcpu, &attr);
1185 		break;
1186 	}
1187 	case KVM_GET_VCPU_EVENTS: {
1188 		struct kvm_vcpu_events events;
1189 
1190 		if (kvm_arm_vcpu_get_events(vcpu, &events))
1191 			return -EINVAL;
1192 
1193 		if (copy_to_user(argp, &events, sizeof(events)))
1194 			return -EFAULT;
1195 
1196 		return 0;
1197 	}
1198 	case KVM_SET_VCPU_EVENTS: {
1199 		struct kvm_vcpu_events events;
1200 
1201 		if (copy_from_user(&events, argp, sizeof(events)))
1202 			return -EFAULT;
1203 
1204 		return kvm_arm_vcpu_set_events(vcpu, &events);
1205 	}
1206 	default:
1207 		r = -EINVAL;
1208 	}
1209 
1210 	return r;
1211 }
1212 
1213 /**
1214  * kvm_vm_ioctl_get_dirty_log - get and clear the log of dirty pages in a slot
1215  * @kvm: kvm instance
1216  * @log: slot id and address to which we copy the log
1217  *
1218  * Steps 1-4 below provide general overview of dirty page logging. See
1219  * kvm_get_dirty_log_protect() function description for additional details.
1220  *
1221  * We call kvm_get_dirty_log_protect() to handle steps 1-3, upon return we
1222  * always flush the TLB (step 4) even if previous step failed  and the dirty
1223  * bitmap may be corrupt. Regardless of previous outcome the KVM logging API
1224  * does not preclude user space subsequent dirty log read. Flushing TLB ensures
1225  * writes will be marked dirty for next log read.
1226  *
1227  *   1. Take a snapshot of the bit and clear it if needed.
1228  *   2. Write protect the corresponding page.
1229  *   3. Copy the snapshot to the userspace.
1230  *   4. Flush TLB's if needed.
1231  */
kvm_vm_ioctl_get_dirty_log(struct kvm * kvm,struct kvm_dirty_log * log)1232 int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
1233 {
1234 	bool is_dirty = false;
1235 	int r;
1236 
1237 	mutex_lock(&kvm->slots_lock);
1238 
1239 	r = kvm_get_dirty_log_protect(kvm, log, &is_dirty);
1240 
1241 	if (is_dirty)
1242 		kvm_flush_remote_tlbs(kvm);
1243 
1244 	mutex_unlock(&kvm->slots_lock);
1245 	return r;
1246 }
1247 
kvm_vm_ioctl_set_device_addr(struct kvm * kvm,struct kvm_arm_device_addr * dev_addr)1248 static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
1249 					struct kvm_arm_device_addr *dev_addr)
1250 {
1251 	unsigned long dev_id, type;
1252 
1253 	dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >>
1254 		KVM_ARM_DEVICE_ID_SHIFT;
1255 	type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >>
1256 		KVM_ARM_DEVICE_TYPE_SHIFT;
1257 
1258 	switch (dev_id) {
1259 	case KVM_ARM_DEVICE_VGIC_V2:
1260 		if (!vgic_present)
1261 			return -ENXIO;
1262 		return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
1263 	default:
1264 		return -ENODEV;
1265 	}
1266 }
1267 
kvm_arch_vm_ioctl(struct file * filp,unsigned int ioctl,unsigned long arg)1268 long kvm_arch_vm_ioctl(struct file *filp,
1269 		       unsigned int ioctl, unsigned long arg)
1270 {
1271 	struct kvm *kvm = filp->private_data;
1272 	void __user *argp = (void __user *)arg;
1273 
1274 	switch (ioctl) {
1275 	case KVM_CREATE_IRQCHIP: {
1276 		int ret;
1277 		if (!vgic_present)
1278 			return -ENXIO;
1279 		mutex_lock(&kvm->lock);
1280 		ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
1281 		mutex_unlock(&kvm->lock);
1282 		return ret;
1283 	}
1284 	case KVM_ARM_SET_DEVICE_ADDR: {
1285 		struct kvm_arm_device_addr dev_addr;
1286 
1287 		if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
1288 			return -EFAULT;
1289 		return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
1290 	}
1291 	case KVM_ARM_PREFERRED_TARGET: {
1292 		int err;
1293 		struct kvm_vcpu_init init;
1294 
1295 		err = kvm_vcpu_preferred_target(&init);
1296 		if (err)
1297 			return err;
1298 
1299 		if (copy_to_user(argp, &init, sizeof(init)))
1300 			return -EFAULT;
1301 
1302 		return 0;
1303 	}
1304 	default:
1305 		return -EINVAL;
1306 	}
1307 }
1308 
cpu_init_hyp_mode(void * dummy)1309 static void cpu_init_hyp_mode(void *dummy)
1310 {
1311 	phys_addr_t pgd_ptr;
1312 	unsigned long hyp_stack_ptr;
1313 	unsigned long stack_page;
1314 	unsigned long vector_ptr;
1315 
1316 	/* Switch from the HYP stub to our own HYP init vector */
1317 	__hyp_set_vectors(kvm_get_idmap_vector());
1318 
1319 	pgd_ptr = kvm_mmu_get_httbr();
1320 	stack_page = __this_cpu_read(kvm_arm_hyp_stack_page);
1321 	hyp_stack_ptr = stack_page + PAGE_SIZE;
1322 	vector_ptr = (unsigned long)kvm_get_hyp_vector();
1323 
1324 	__cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
1325 	__cpu_init_stage2();
1326 }
1327 
cpu_hyp_reset(void)1328 static void cpu_hyp_reset(void)
1329 {
1330 	if (!is_kernel_in_hyp_mode())
1331 		__hyp_reset_vectors();
1332 }
1333 
cpu_hyp_reinit(void)1334 static void cpu_hyp_reinit(void)
1335 {
1336 	cpu_hyp_reset();
1337 
1338 	if (is_kernel_in_hyp_mode()) {
1339 		/*
1340 		 * __cpu_init_stage2() is safe to call even if the PM
1341 		 * event was cancelled before the CPU was reset.
1342 		 */
1343 		__cpu_init_stage2();
1344 		kvm_timer_init_vhe();
1345 	} else {
1346 		cpu_init_hyp_mode(NULL);
1347 	}
1348 
1349 	kvm_arm_init_debug();
1350 
1351 	if (vgic_present)
1352 		kvm_vgic_init_cpu_hardware();
1353 }
1354 
_kvm_arch_hardware_enable(void * discard)1355 static void _kvm_arch_hardware_enable(void *discard)
1356 {
1357 	if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
1358 		cpu_hyp_reinit();
1359 		__this_cpu_write(kvm_arm_hardware_enabled, 1);
1360 	}
1361 }
1362 
kvm_arch_hardware_enable(void)1363 int kvm_arch_hardware_enable(void)
1364 {
1365 	_kvm_arch_hardware_enable(NULL);
1366 	return 0;
1367 }
1368 
_kvm_arch_hardware_disable(void * discard)1369 static void _kvm_arch_hardware_disable(void *discard)
1370 {
1371 	if (__this_cpu_read(kvm_arm_hardware_enabled)) {
1372 		cpu_hyp_reset();
1373 		__this_cpu_write(kvm_arm_hardware_enabled, 0);
1374 	}
1375 }
1376 
kvm_arch_hardware_disable(void)1377 void kvm_arch_hardware_disable(void)
1378 {
1379 	_kvm_arch_hardware_disable(NULL);
1380 }
1381 
1382 #ifdef CONFIG_CPU_PM
hyp_init_cpu_pm_notifier(struct notifier_block * self,unsigned long cmd,void * v)1383 static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
1384 				    unsigned long cmd,
1385 				    void *v)
1386 {
1387 	/*
1388 	 * kvm_arm_hardware_enabled is left with its old value over
1389 	 * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
1390 	 * re-enable hyp.
1391 	 */
1392 	switch (cmd) {
1393 	case CPU_PM_ENTER:
1394 		if (__this_cpu_read(kvm_arm_hardware_enabled))
1395 			/*
1396 			 * don't update kvm_arm_hardware_enabled here
1397 			 * so that the hardware will be re-enabled
1398 			 * when we resume. See below.
1399 			 */
1400 			cpu_hyp_reset();
1401 
1402 		return NOTIFY_OK;
1403 	case CPU_PM_ENTER_FAILED:
1404 	case CPU_PM_EXIT:
1405 		if (__this_cpu_read(kvm_arm_hardware_enabled))
1406 			/* The hardware was enabled before suspend. */
1407 			cpu_hyp_reinit();
1408 
1409 		return NOTIFY_OK;
1410 
1411 	default:
1412 		return NOTIFY_DONE;
1413 	}
1414 }
1415 
1416 static struct notifier_block hyp_init_cpu_pm_nb = {
1417 	.notifier_call = hyp_init_cpu_pm_notifier,
1418 };
1419 
hyp_cpu_pm_init(void)1420 static void __init hyp_cpu_pm_init(void)
1421 {
1422 	cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
1423 }
hyp_cpu_pm_exit(void)1424 static void __init hyp_cpu_pm_exit(void)
1425 {
1426 	cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
1427 }
1428 #else
hyp_cpu_pm_init(void)1429 static inline void hyp_cpu_pm_init(void)
1430 {
1431 }
hyp_cpu_pm_exit(void)1432 static inline void hyp_cpu_pm_exit(void)
1433 {
1434 }
1435 #endif
1436 
init_common_resources(void)1437 static int init_common_resources(void)
1438 {
1439 	/* set size of VMID supported by CPU */
1440 	kvm_vmid_bits = kvm_get_vmid_bits();
1441 	kvm_info("%d-bit VMID\n", kvm_vmid_bits);
1442 
1443 	return 0;
1444 }
1445 
init_subsystems(void)1446 static int init_subsystems(void)
1447 {
1448 	int err = 0;
1449 
1450 	/*
1451 	 * Enable hardware so that subsystem initialisation can access EL2.
1452 	 */
1453 	on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);
1454 
1455 	/*
1456 	 * Register CPU lower-power notifier
1457 	 */
1458 	hyp_cpu_pm_init();
1459 
1460 	/*
1461 	 * Init HYP view of VGIC
1462 	 */
1463 	err = kvm_vgic_hyp_init();
1464 	switch (err) {
1465 	case 0:
1466 		vgic_present = true;
1467 		break;
1468 	case -ENODEV:
1469 	case -ENXIO:
1470 		vgic_present = false;
1471 		err = 0;
1472 		break;
1473 	default:
1474 		goto out;
1475 	}
1476 
1477 	/*
1478 	 * Init HYP architected timer support
1479 	 */
1480 	err = kvm_timer_hyp_init(vgic_present);
1481 	if (err)
1482 		goto out;
1483 
1484 	kvm_perf_init();
1485 	kvm_coproc_table_init();
1486 
1487 out:
1488 	on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
1489 
1490 	return err;
1491 }
1492 
teardown_hyp_mode(void)1493 static void teardown_hyp_mode(void)
1494 {
1495 	int cpu;
1496 
1497 	free_hyp_pgds();
1498 	for_each_possible_cpu(cpu)
1499 		free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
1500 	hyp_cpu_pm_exit();
1501 }
1502 
1503 /**
1504  * Inits Hyp-mode on all online CPUs
1505  */
init_hyp_mode(void)1506 static int init_hyp_mode(void)
1507 {
1508 	int cpu;
1509 	int err = 0;
1510 
1511 	/*
1512 	 * Allocate Hyp PGD and setup Hyp identity mapping
1513 	 */
1514 	err = kvm_mmu_init();
1515 	if (err)
1516 		goto out_err;
1517 
1518 	/*
1519 	 * Allocate stack pages for Hypervisor-mode
1520 	 */
1521 	for_each_possible_cpu(cpu) {
1522 		unsigned long stack_page;
1523 
1524 		stack_page = __get_free_page(GFP_KERNEL);
1525 		if (!stack_page) {
1526 			err = -ENOMEM;
1527 			goto out_err;
1528 		}
1529 
1530 		per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
1531 	}
1532 
1533 	/*
1534 	 * Map the Hyp-code called directly from the host
1535 	 */
1536 	err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start),
1537 				  kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC);
1538 	if (err) {
1539 		kvm_err("Cannot map world-switch code\n");
1540 		goto out_err;
1541 	}
1542 
1543 	err = create_hyp_mappings(kvm_ksym_ref(__start_rodata),
1544 				  kvm_ksym_ref(__end_rodata), PAGE_HYP_RO);
1545 	if (err) {
1546 		kvm_err("Cannot map rodata section\n");
1547 		goto out_err;
1548 	}
1549 
1550 	err = create_hyp_mappings(kvm_ksym_ref(__bss_start),
1551 				  kvm_ksym_ref(__bss_stop), PAGE_HYP_RO);
1552 	if (err) {
1553 		kvm_err("Cannot map bss section\n");
1554 		goto out_err;
1555 	}
1556 
1557 	err = kvm_map_vectors();
1558 	if (err) {
1559 		kvm_err("Cannot map vectors\n");
1560 		goto out_err;
1561 	}
1562 
1563 	/*
1564 	 * Map the Hyp stack pages
1565 	 */
1566 	for_each_possible_cpu(cpu) {
1567 		char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
1568 		err = create_hyp_mappings(stack_page, stack_page + PAGE_SIZE,
1569 					  PAGE_HYP);
1570 
1571 		if (err) {
1572 			kvm_err("Cannot map hyp stack\n");
1573 			goto out_err;
1574 		}
1575 	}
1576 
1577 	for_each_possible_cpu(cpu) {
1578 		kvm_cpu_context_t *cpu_ctxt;
1579 
1580 		cpu_ctxt = per_cpu_ptr(&kvm_host_cpu_state, cpu);
1581 		err = create_hyp_mappings(cpu_ctxt, cpu_ctxt + 1, PAGE_HYP);
1582 
1583 		if (err) {
1584 			kvm_err("Cannot map host CPU state: %d\n", err);
1585 			goto out_err;
1586 		}
1587 	}
1588 
1589 	err = hyp_map_aux_data();
1590 	if (err)
1591 		kvm_err("Cannot map host auxilary data: %d\n", err);
1592 
1593 	return 0;
1594 
1595 out_err:
1596 	teardown_hyp_mode();
1597 	kvm_err("error initializing Hyp mode: %d\n", err);
1598 	return err;
1599 }
1600 
check_kvm_target_cpu(void * ret)1601 static void check_kvm_target_cpu(void *ret)
1602 {
1603 	*(int *)ret = kvm_target_cpu();
1604 }
1605 
kvm_mpidr_to_vcpu(struct kvm * kvm,unsigned long mpidr)1606 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
1607 {
1608 	struct kvm_vcpu *vcpu;
1609 	int i;
1610 
1611 	mpidr &= MPIDR_HWID_BITMASK;
1612 	kvm_for_each_vcpu(i, vcpu, kvm) {
1613 		if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
1614 			return vcpu;
1615 	}
1616 	return NULL;
1617 }
1618 
kvm_arch_has_irq_bypass(void)1619 bool kvm_arch_has_irq_bypass(void)
1620 {
1621 	return true;
1622 }
1623 
kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer * cons,struct irq_bypass_producer * prod)1624 int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
1625 				      struct irq_bypass_producer *prod)
1626 {
1627 	struct kvm_kernel_irqfd *irqfd =
1628 		container_of(cons, struct kvm_kernel_irqfd, consumer);
1629 
1630 	return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
1631 					  &irqfd->irq_entry);
1632 }
kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer * cons,struct irq_bypass_producer * prod)1633 void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
1634 				      struct irq_bypass_producer *prod)
1635 {
1636 	struct kvm_kernel_irqfd *irqfd =
1637 		container_of(cons, struct kvm_kernel_irqfd, consumer);
1638 
1639 	kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
1640 				     &irqfd->irq_entry);
1641 }
1642 
kvm_arch_irq_bypass_stop(struct irq_bypass_consumer * cons)1643 void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
1644 {
1645 	struct kvm_kernel_irqfd *irqfd =
1646 		container_of(cons, struct kvm_kernel_irqfd, consumer);
1647 
1648 	kvm_arm_halt_guest(irqfd->kvm);
1649 }
1650 
kvm_arch_irq_bypass_start(struct irq_bypass_consumer * cons)1651 void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
1652 {
1653 	struct kvm_kernel_irqfd *irqfd =
1654 		container_of(cons, struct kvm_kernel_irqfd, consumer);
1655 
1656 	kvm_arm_resume_guest(irqfd->kvm);
1657 }
1658 
1659 /**
1660  * Initialize Hyp-mode and memory mappings on all CPUs.
1661  */
kvm_arch_init(void * opaque)1662 int kvm_arch_init(void *opaque)
1663 {
1664 	int err;
1665 	int ret, cpu;
1666 	bool in_hyp_mode;
1667 
1668 	if (!is_hyp_mode_available()) {
1669 		kvm_info("HYP mode not available\n");
1670 		return -ENODEV;
1671 	}
1672 
1673 	if (!kvm_arch_check_sve_has_vhe()) {
1674 		kvm_pr_unimpl("SVE system without VHE unsupported.  Broken cpu?");
1675 		return -ENODEV;
1676 	}
1677 
1678 	for_each_online_cpu(cpu) {
1679 		smp_call_function_single(cpu, check_kvm_target_cpu, &ret, 1);
1680 		if (ret < 0) {
1681 			kvm_err("Error, CPU %d not supported!\n", cpu);
1682 			return -ENODEV;
1683 		}
1684 	}
1685 
1686 	err = init_common_resources();
1687 	if (err)
1688 		return err;
1689 
1690 	in_hyp_mode = is_kernel_in_hyp_mode();
1691 
1692 	if (!in_hyp_mode) {
1693 		err = init_hyp_mode();
1694 		if (err)
1695 			goto out_err;
1696 	}
1697 
1698 	err = init_subsystems();
1699 	if (err)
1700 		goto out_hyp;
1701 
1702 	if (in_hyp_mode)
1703 		kvm_info("VHE mode initialized successfully\n");
1704 	else
1705 		kvm_info("Hyp mode initialized successfully\n");
1706 
1707 	return 0;
1708 
1709 out_hyp:
1710 	if (!in_hyp_mode)
1711 		teardown_hyp_mode();
1712 out_err:
1713 	return err;
1714 }
1715 
1716 /* NOP: Compiling as a module not supported */
kvm_arch_exit(void)1717 void kvm_arch_exit(void)
1718 {
1719 	kvm_perf_teardown();
1720 }
1721 
arm_init(void)1722 static int arm_init(void)
1723 {
1724 	int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
1725 	return rc;
1726 }
1727 
1728 module_init(arm_init);
1729