Merge tag 'kvm-x86-generic-6.8' of https://github.com/kvm-x86/linux into HEAD

[thirdparty/kernel/stable.git] / arch / arm64 / kvm / arm.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 */

#include <linux/bug.h>
#include <linux/cpu_pm.h>
#include <linux/entry-kvm.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/mman.h>
#include <linux/sched.h>
#include <linux/kvm.h>
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/sched/stat.h>
#include <linux/psci.h>
#include <trace/events/kvm.h>

#define CREATE_TRACE_POINTS
#include "trace_arm.h"

#include <linux/uaccess.h>
#include <asm/ptrace.h>
#include <asm/mman.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/virt.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_nested.h>
#include <asm/kvm_pkvm.h>
#include <asm/kvm_emulate.h>
#include <asm/sections.h>

#include <kvm/arm_hypercalls.h>
#include <kvm/arm_pmu.h>
#include <kvm/arm_psci.h>

static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT;

DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);

DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);

DECLARE_KVM_NVHE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);

static bool vgic_present, kvm_arm_initialised;

static DEFINE_PER_CPU(unsigned char, kvm_hyp_initialized);
DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);

bool is_kvm_arm_initialised(void)
{
        return kvm_arm_initialised;
}

int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
        return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}

int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
                            struct kvm_enable_cap *cap)
{
        int r;
        u64 new_cap;

        if (cap->flags)
                return -EINVAL;

        switch (cap->cap) {
        case KVM_CAP_ARM_NISV_TO_USER:
                r = 0;
                set_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
                        &kvm->arch.flags);
                break;
        case KVM_CAP_ARM_MTE:
                mutex_lock(&kvm->lock);
                if (!system_supports_mte() || kvm->created_vcpus) {
                        r = -EINVAL;
                } else {
                        r = 0;
                        set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags);
                }
                mutex_unlock(&kvm->lock);
                break;
        case KVM_CAP_ARM_SYSTEM_SUSPEND:
                r = 0;
                set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags);
                break;
        case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE:
                new_cap = cap->args[0];

                mutex_lock(&kvm->slots_lock);
                /*
                 * To keep things simple, allow changing the chunk
                 * size only when no memory slots have been created.
                 */
                if (!kvm_are_all_memslots_empty(kvm)) {
                        r = -EINVAL;
                } else if (new_cap && !kvm_is_block_size_supported(new_cap)) {
                        r = -EINVAL;
                } else {
                        r = 0;
                        kvm->arch.mmu.split_page_chunk_size = new_cap;
                }
                mutex_unlock(&kvm->slots_lock);
                break;
        default:
                r = -EINVAL;
                break;
        }

        return r;
}

static int kvm_arm_default_max_vcpus(void)
{
        return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
}

/**
 * kvm_arch_init_vm - initializes a VM data structure
 * @kvm:        pointer to the KVM struct
 */
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
        int ret;

        mutex_init(&kvm->arch.config_lock);

#ifdef CONFIG_LOCKDEP
        /* Clue in lockdep that the config_lock must be taken inside kvm->lock */
        mutex_lock(&kvm->lock);
        mutex_lock(&kvm->arch.config_lock);
        mutex_unlock(&kvm->arch.config_lock);
        mutex_unlock(&kvm->lock);
#endif

        ret = kvm_share_hyp(kvm, kvm + 1);
        if (ret)
                return ret;

        ret = pkvm_init_host_vm(kvm);
        if (ret)
                goto err_unshare_kvm;

        if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL_ACCOUNT)) {
                ret = -ENOMEM;
                goto err_unshare_kvm;
        }
        cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask);

        ret = kvm_init_stage2_mmu(kvm, &kvm->arch.mmu, type);
        if (ret)
                goto err_free_cpumask;

        kvm_vgic_early_init(kvm);

        kvm_timer_init_vm(kvm);

        /* The maximum number of VCPUs is limited by the host's GIC model */
        kvm->max_vcpus = kvm_arm_default_max_vcpus();

        kvm_arm_init_hypercalls(kvm);

        bitmap_zero(kvm->arch.vcpu_features, KVM_VCPU_MAX_FEATURES);

        return 0;

err_free_cpumask:
        free_cpumask_var(kvm->arch.supported_cpus);
err_unshare_kvm:
        kvm_unshare_hyp(kvm, kvm + 1);
        return ret;
}

vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
        return VM_FAULT_SIGBUS;
}


/**
 * kvm_arch_destroy_vm - destroy the VM data structure
 * @kvm:        pointer to the KVM struct
 */
void kvm_arch_destroy_vm(struct kvm *kvm)
{
        bitmap_free(kvm->arch.pmu_filter);
        free_cpumask_var(kvm->arch.supported_cpus);

        kvm_vgic_destroy(kvm);

        if (is_protected_kvm_enabled())
                pkvm_destroy_hyp_vm(kvm);

        kfree(kvm->arch.mpidr_data);
        kvm_destroy_vcpus(kvm);

        kvm_unshare_hyp(kvm, kvm + 1);

        kvm_arm_teardown_hypercalls(kvm);
}

int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
        int r;
        switch (ext) {
        case KVM_CAP_IRQCHIP:
                r = vgic_present;
                break;
        case KVM_CAP_IOEVENTFD:
        case KVM_CAP_USER_MEMORY:
        case KVM_CAP_SYNC_MMU:
        case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
        case KVM_CAP_ONE_REG:
        case KVM_CAP_ARM_PSCI:
        case KVM_CAP_ARM_PSCI_0_2:
        case KVM_CAP_READONLY_MEM:
        case KVM_CAP_MP_STATE:
        case KVM_CAP_IMMEDIATE_EXIT:
        case KVM_CAP_VCPU_EVENTS:
        case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2:
        case KVM_CAP_ARM_NISV_TO_USER:
        case KVM_CAP_ARM_INJECT_EXT_DABT:
        case KVM_CAP_SET_GUEST_DEBUG:
        case KVM_CAP_VCPU_ATTRIBUTES:
        case KVM_CAP_PTP_KVM:
        case KVM_CAP_ARM_SYSTEM_SUSPEND:
        case KVM_CAP_IRQFD_RESAMPLE:
        case KVM_CAP_COUNTER_OFFSET:
                r = 1;
                break;
        case KVM_CAP_SET_GUEST_DEBUG2:
                return KVM_GUESTDBG_VALID_MASK;
        case KVM_CAP_ARM_SET_DEVICE_ADDR:
                r = 1;
                break;
        case KVM_CAP_NR_VCPUS:
                /*
                 * ARM64 treats KVM_CAP_NR_CPUS differently from all other
                 * architectures, as it does not always bound it to
                 * KVM_CAP_MAX_VCPUS. It should not matter much because
                 * this is just an advisory value.
                 */
                r = min_t(unsigned int, num_online_cpus(),
                          kvm_arm_default_max_vcpus());
                break;
        case KVM_CAP_MAX_VCPUS:
        case KVM_CAP_MAX_VCPU_ID:
                if (kvm)
                        r = kvm->max_vcpus;
                else
                        r = kvm_arm_default_max_vcpus();
                break;
        case KVM_CAP_MSI_DEVID:
                if (!kvm)
                        r = -EINVAL;
                else
                        r = kvm->arch.vgic.msis_require_devid;
                break;
        case KVM_CAP_ARM_USER_IRQ:
                /*
                 * 1: EL1_VTIMER, EL1_PTIMER, and PMU.
                 * (bump this number if adding more devices)
                 */
                r = 1;
                break;
        case KVM_CAP_ARM_MTE:
                r = system_supports_mte();
                break;
        case KVM_CAP_STEAL_TIME:
                r = kvm_arm_pvtime_supported();
                break;
        case KVM_CAP_ARM_EL1_32BIT:
                r = cpus_have_final_cap(ARM64_HAS_32BIT_EL1);
                break;
        case KVM_CAP_GUEST_DEBUG_HW_BPS:
                r = get_num_brps();
                break;
        case KVM_CAP_GUEST_DEBUG_HW_WPS:
                r = get_num_wrps();
                break;
        case KVM_CAP_ARM_PMU_V3:
                r = kvm_arm_support_pmu_v3();
                break;
        case KVM_CAP_ARM_INJECT_SERROR_ESR:
                r = cpus_have_final_cap(ARM64_HAS_RAS_EXTN);
                break;
        case KVM_CAP_ARM_VM_IPA_SIZE:
                r = get_kvm_ipa_limit();
                break;
        case KVM_CAP_ARM_SVE:
                r = system_supports_sve();
                break;
        case KVM_CAP_ARM_PTRAUTH_ADDRESS:
        case KVM_CAP_ARM_PTRAUTH_GENERIC:
                r = system_has_full_ptr_auth();
                break;
        case KVM_CAP_ARM_EAGER_SPLIT_CHUNK_SIZE:
                if (kvm)
                        r = kvm->arch.mmu.split_page_chunk_size;
                else
                        r = KVM_ARM_EAGER_SPLIT_CHUNK_SIZE_DEFAULT;
                break;
        case KVM_CAP_ARM_SUPPORTED_BLOCK_SIZES:
                r = kvm_supported_block_sizes();
                break;
        case KVM_CAP_ARM_SUPPORTED_REG_MASK_RANGES:
                r = BIT(0);
                break;
        default:
                r = 0;
        }

        return r;
}

long kvm_arch_dev_ioctl(struct file *filp,
                        unsigned int ioctl, unsigned long arg)
{
        return -EINVAL;
}

struct kvm *kvm_arch_alloc_vm(void)
{
        size_t sz = sizeof(struct kvm);

        if (!has_vhe())
                return kzalloc(sz, GFP_KERNEL_ACCOUNT);

        return __vmalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM | __GFP_ZERO);
}

int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
{
        if (irqchip_in_kernel(kvm) && vgic_initialized(kvm))
                return -EBUSY;

        if (id >= kvm->max_vcpus)
                return -EINVAL;

        return 0;
}

int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
        int err;

        spin_lock_init(&vcpu->arch.mp_state_lock);

#ifdef CONFIG_LOCKDEP
        /* Inform lockdep that the config_lock is acquired after vcpu->mutex */
        mutex_lock(&vcpu->mutex);
        mutex_lock(&vcpu->kvm->arch.config_lock);
        mutex_unlock(&vcpu->kvm->arch.config_lock);
        mutex_unlock(&vcpu->mutex);
#endif

        /* Force users to call KVM_ARM_VCPU_INIT */
        vcpu_clear_flag(vcpu, VCPU_INITIALIZED);

        vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;

        /*
         * Default value for the FP state, will be overloaded at load
         * time if we support FP (pretty likely)
         */
        vcpu->arch.fp_state = FP_STATE_FREE;

        /* Set up the timer */
        kvm_timer_vcpu_init(vcpu);

        kvm_pmu_vcpu_init(vcpu);

        kvm_arm_reset_debug_ptr(vcpu);

        kvm_arm_pvtime_vcpu_init(&vcpu->arch);

        vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;

        err = kvm_vgic_vcpu_init(vcpu);
        if (err)
                return err;

        return kvm_share_hyp(vcpu, vcpu + 1);
}

void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
}

void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
        if (vcpu_has_run_once(vcpu) && unlikely(!irqchip_in_kernel(vcpu->kvm)))
                static_branch_dec(&userspace_irqchip_in_use);

        kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
        kvm_timer_vcpu_terminate(vcpu);
        kvm_pmu_vcpu_destroy(vcpu);
        kvm_vgic_vcpu_destroy(vcpu);
        kvm_arm_vcpu_destroy(vcpu);
}

void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
{

}

void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
{

}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
        struct kvm_s2_mmu *mmu;
        int *last_ran;

        mmu = vcpu->arch.hw_mmu;
        last_ran = this_cpu_ptr(mmu->last_vcpu_ran);

        /*
         * We guarantee that both TLBs and I-cache are private to each
         * vcpu. If detecting that a vcpu from the same VM has
         * previously run on the same physical CPU, call into the
         * hypervisor code to nuke the relevant contexts.
         *
         * We might get preempted before the vCPU actually runs, but
         * over-invalidation doesn't affect correctness.
         */
        if (*last_ran != vcpu->vcpu_idx) {
                kvm_call_hyp(__kvm_flush_cpu_context, mmu);
                *last_ran = vcpu->vcpu_idx;
        }

        vcpu->cpu = cpu;

        kvm_vgic_load(vcpu);
        kvm_timer_vcpu_load(vcpu);
        if (has_vhe())
                kvm_vcpu_load_vhe(vcpu);
        kvm_arch_vcpu_load_fp(vcpu);
        kvm_vcpu_pmu_restore_guest(vcpu);
        if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
                kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);

        if (single_task_running())
                vcpu_clear_wfx_traps(vcpu);
        else
                vcpu_set_wfx_traps(vcpu);

        if (vcpu_has_ptrauth(vcpu))
                vcpu_ptrauth_disable(vcpu);
        kvm_arch_vcpu_load_debug_state_flags(vcpu);

        if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
                vcpu_set_on_unsupported_cpu(vcpu);
}

void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
        kvm_arch_vcpu_put_debug_state_flags(vcpu);
        kvm_arch_vcpu_put_fp(vcpu);
        if (has_vhe())
                kvm_vcpu_put_vhe(vcpu);
        kvm_timer_vcpu_put(vcpu);
        kvm_vgic_put(vcpu);
        kvm_vcpu_pmu_restore_host(vcpu);
        kvm_arm_vmid_clear_active();

        vcpu_clear_on_unsupported_cpu(vcpu);
        vcpu->cpu = -1;
}

static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
{
        WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
        kvm_make_request(KVM_REQ_SLEEP, vcpu);
        kvm_vcpu_kick(vcpu);
}

void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
{
        spin_lock(&vcpu->arch.mp_state_lock);
        __kvm_arm_vcpu_power_off(vcpu);
        spin_unlock(&vcpu->arch.mp_state_lock);
}

bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu)
{
        return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_STOPPED;
}

static void kvm_arm_vcpu_suspend(struct kvm_vcpu *vcpu)
{
        WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_SUSPENDED);
        kvm_make_request(KVM_REQ_SUSPEND, vcpu);
        kvm_vcpu_kick(vcpu);
}

static bool kvm_arm_vcpu_suspended(struct kvm_vcpu *vcpu)
{
        return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_SUSPENDED;
}

int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        *mp_state = READ_ONCE(vcpu->arch.mp_state);

        return 0;
}

int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
                                    struct kvm_mp_state *mp_state)
{
        int ret = 0;

        spin_lock(&vcpu->arch.mp_state_lock);

        switch (mp_state->mp_state) {
        case KVM_MP_STATE_RUNNABLE:
                WRITE_ONCE(vcpu->arch.mp_state, *mp_state);
                break;
        case KVM_MP_STATE_STOPPED:
                __kvm_arm_vcpu_power_off(vcpu);
                break;
        case KVM_MP_STATE_SUSPENDED:
                kvm_arm_vcpu_suspend(vcpu);
                break;
        default:
                ret = -EINVAL;
        }

        spin_unlock(&vcpu->arch.mp_state_lock);

        return ret;
}

/**
 * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
 * @v:          The VCPU pointer
 *
 * If the guest CPU is not waiting for interrupts or an interrupt line is
 * asserted, the CPU is by definition runnable.
 */
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
        bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
        return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
                && !kvm_arm_vcpu_stopped(v) && !v->arch.pause);
}

bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
        return vcpu_mode_priv(vcpu);
}

#ifdef CONFIG_GUEST_PERF_EVENTS
unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
{
        return *vcpu_pc(vcpu);
}
#endif

static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
{
        return vcpu_get_flag(vcpu, VCPU_INITIALIZED);
}

static void kvm_init_mpidr_data(struct kvm *kvm)
{
        struct kvm_mpidr_data *data = NULL;
        unsigned long c, mask, nr_entries;
        u64 aff_set = 0, aff_clr = ~0UL;
        struct kvm_vcpu *vcpu;

        mutex_lock(&kvm->arch.config_lock);

        if (kvm->arch.mpidr_data || atomic_read(&kvm->online_vcpus) == 1)
                goto out;

        kvm_for_each_vcpu(c, vcpu, kvm) {
                u64 aff = kvm_vcpu_get_mpidr_aff(vcpu);
                aff_set |= aff;
                aff_clr &= aff;
        }

        /*
         * A significant bit can be either 0 or 1, and will only appear in
         * aff_set. Use aff_clr to weed out the useless stuff.
         */
        mask = aff_set ^ aff_clr;
        nr_entries = BIT_ULL(hweight_long(mask));

        /*
         * Don't let userspace fool us. If we need more than a single page
         * to describe the compressed MPIDR array, just fall back to the
         * iterative method. Single vcpu VMs do not need this either.
         */
        if (struct_size(data, cmpidr_to_idx, nr_entries) <= PAGE_SIZE)
                data = kzalloc(struct_size(data, cmpidr_to_idx, nr_entries),
                               GFP_KERNEL_ACCOUNT);

        if (!data)
                goto out;

        data->mpidr_mask = mask;

        kvm_for_each_vcpu(c, vcpu, kvm) {
                u64 aff = kvm_vcpu_get_mpidr_aff(vcpu);
                u16 index = kvm_mpidr_index(data, aff);

                data->cmpidr_to_idx[index] = c;
        }

        kvm->arch.mpidr_data = data;
out:
        mutex_unlock(&kvm->arch.config_lock);
}

/*
 * Handle both the initialisation that is being done when the vcpu is
 * run for the first time, as well as the updates that must be
 * performed each time we get a new thread dealing with this vcpu.
 */
int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
{
        struct kvm *kvm = vcpu->kvm;
        int ret;

        if (!kvm_vcpu_initialized(vcpu))
                return -ENOEXEC;

        if (!kvm_arm_vcpu_is_finalized(vcpu))
                return -EPERM;

        ret = kvm_arch_vcpu_run_map_fp(vcpu);
        if (ret)
                return ret;

        if (likely(vcpu_has_run_once(vcpu)))
                return 0;

        kvm_init_mpidr_data(kvm);

        kvm_arm_vcpu_init_debug(vcpu);

        if (likely(irqchip_in_kernel(kvm))) {
                /*
                 * Map the VGIC hardware resources before running a vcpu the
                 * first time on this VM.
                 */
                ret = kvm_vgic_map_resources(kvm);
                if (ret)
                        return ret;
        }

        if (vcpu_has_nv(vcpu)) {
                ret = kvm_init_nv_sysregs(vcpu->kvm);
                if (ret)
                        return ret;
        }

        ret = kvm_timer_enable(vcpu);
        if (ret)
                return ret;

        ret = kvm_arm_pmu_v3_enable(vcpu);
        if (ret)
                return ret;

        if (is_protected_kvm_enabled()) {
                ret = pkvm_create_hyp_vm(kvm);
                if (ret)
                        return ret;
        }

        if (!irqchip_in_kernel(kvm)) {
                /*
                 * Tell the rest of the code that there are userspace irqchip
                 * VMs in the wild.
                 */
                static_branch_inc(&userspace_irqchip_in_use);
        }

        /*
         * Initialize traps for protected VMs.
         * NOTE: Move to run in EL2 directly, rather than via a hypercall, once
         * the code is in place for first run initialization at EL2.
         */
        if (kvm_vm_is_protected(kvm))
                kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);

        mutex_lock(&kvm->arch.config_lock);
        set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
        mutex_unlock(&kvm->arch.config_lock);

        return ret;
}

bool kvm_arch_intc_initialized(struct kvm *kvm)
{
        return vgic_initialized(kvm);
}

void kvm_arm_halt_guest(struct kvm *kvm)
{
        unsigned long i;
        struct kvm_vcpu *vcpu;

        kvm_for_each_vcpu(i, vcpu, kvm)
                vcpu->arch.pause = true;
        kvm_make_all_cpus_request(kvm, KVM_REQ_SLEEP);
}

void kvm_arm_resume_guest(struct kvm *kvm)
{
        unsigned long i;
        struct kvm_vcpu *vcpu;

        kvm_for_each_vcpu(i, vcpu, kvm) {
                vcpu->arch.pause = false;
                __kvm_vcpu_wake_up(vcpu);
        }
}

static void kvm_vcpu_sleep(struct kvm_vcpu *vcpu)
{
        struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);

        rcuwait_wait_event(wait,
                           (!kvm_arm_vcpu_stopped(vcpu)) && (!vcpu->arch.pause),
                           TASK_INTERRUPTIBLE);

        if (kvm_arm_vcpu_stopped(vcpu) || vcpu->arch.pause) {
                /* Awaken to handle a signal, request we sleep again later. */
                kvm_make_request(KVM_REQ_SLEEP, vcpu);
        }

        /*
         * Make sure we will observe a potential reset request if we've
         * observed a change to the power state. Pairs with the smp_wmb() in
         * kvm_psci_vcpu_on().
         */
        smp_rmb();
}

/**
 * kvm_vcpu_wfi - emulate Wait-For-Interrupt behavior
 * @vcpu:       The VCPU pointer
 *
 * Suspend execution of a vCPU until a valid wake event is detected, i.e. until
 * the vCPU is runnable.  The vCPU may or may not be scheduled out, depending
 * on when a wake event arrives, e.g. there may already be a pending wake event.
 */
void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
{
        /*
         * Sync back the state of the GIC CPU interface so that we have
         * the latest PMR and group enables. This ensures that
         * kvm_arch_vcpu_runnable has up-to-date data to decide whether
         * we have pending interrupts, e.g. when determining if the
         * vCPU should block.
         *
         * For the same reason, we want to tell GICv4 that we need
         * doorbells to be signalled, should an interrupt become pending.
         */
        preempt_disable();
        kvm_vgic_vmcr_sync(vcpu);
        vcpu_set_flag(vcpu, IN_WFI);
        vgic_v4_put(vcpu);
        preempt_enable();

        kvm_vcpu_halt(vcpu);
        vcpu_clear_flag(vcpu, IN_WFIT);

        preempt_disable();
        vcpu_clear_flag(vcpu, IN_WFI);
        vgic_v4_load(vcpu);
        preempt_enable();
}

static int kvm_vcpu_suspend(struct kvm_vcpu *vcpu)
{
        if (!kvm_arm_vcpu_suspended(vcpu))
                return 1;

        kvm_vcpu_wfi(vcpu);

        /*
         * The suspend state is sticky; we do not leave it until userspace
         * explicitly marks the vCPU as runnable. Request that we suspend again
         * later.
         */
        kvm_make_request(KVM_REQ_SUSPEND, vcpu);

        /*
         * Check to make sure the vCPU is actually runnable. If so, exit to
         * userspace informing it of the wakeup condition.
         */
        if (kvm_arch_vcpu_runnable(vcpu)) {
                memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
                vcpu->run->system_event.type = KVM_SYSTEM_EVENT_WAKEUP;
                vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
                return 0;
        }

        /*
         * Otherwise, we were unblocked to process a different event, such as a
         * pending signal. Return 1 and allow kvm_arch_vcpu_ioctl_run() to
         * process the event.
         */
        return 1;
}

/**
 * check_vcpu_requests - check and handle pending vCPU requests
 * @vcpu:       the VCPU pointer
 *
 * Return: 1 if we should enter the guest
 *         0 if we should exit to userspace
 *         < 0 if we should exit to userspace, where the return value indicates
 *         an error
 */
static int check_vcpu_requests(struct kvm_vcpu *vcpu)
{
        if (kvm_request_pending(vcpu)) {
                if (kvm_check_request(KVM_REQ_SLEEP, vcpu))
                        kvm_vcpu_sleep(vcpu);

                if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
                        kvm_reset_vcpu(vcpu);

                /*
                 * Clear IRQ_PENDING requests that were made to guarantee
                 * that a VCPU sees new virtual interrupts.
                 */
                kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);

                if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu))
                        kvm_update_stolen_time(vcpu);

                if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) {
                        /* The distributor enable bits were changed */
                        preempt_disable();
                        vgic_v4_put(vcpu);
                        vgic_v4_load(vcpu);
                        preempt_enable();
                }

                if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu))
                        kvm_vcpu_reload_pmu(vcpu);

                if (kvm_check_request(KVM_REQ_RESYNC_PMU_EL0, vcpu))
                        kvm_vcpu_pmu_restore_guest(vcpu);

                if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
                        return kvm_vcpu_suspend(vcpu);

                if (kvm_dirty_ring_check_request(vcpu))
                        return 0;
        }

        return 1;
}

static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
{
        if (likely(!vcpu_mode_is_32bit(vcpu)))
                return false;

        if (vcpu_has_nv(vcpu))
                return true;

        return !kvm_supports_32bit_el0();
}

/**
 * kvm_vcpu_exit_request - returns true if the VCPU should *not* enter the guest
 * @vcpu:       The VCPU pointer
 * @ret:        Pointer to write optional return code
 *
 * Returns: true if the VCPU needs to return to a preemptible + interruptible
 *          and skip guest entry.
 *
 * This function disambiguates between two different types of exits: exits to a
 * preemptible + interruptible kernel context and exits to userspace. For an
 * exit to userspace, this function will write the return code to ret and return
 * true. For an exit to preemptible + interruptible kernel context (i.e. check
 * for pending work and re-enter), return true without writing to ret.
 */
static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret)
{
        struct kvm_run *run = vcpu->run;

        /*
         * If we're using a userspace irqchip, then check if we need
         * to tell a userspace irqchip about timer or PMU level
         * changes and if so, exit to userspace (the actual level
         * state gets updated in kvm_timer_update_run and
         * kvm_pmu_update_run below).
         */
        if (static_branch_unlikely(&userspace_irqchip_in_use)) {
                if (kvm_timer_should_notify_user(vcpu) ||
                    kvm_pmu_should_notify_user(vcpu)) {
                        *ret = -EINTR;
                        run->exit_reason = KVM_EXIT_INTR;
                        return true;
                }
        }

        if (unlikely(vcpu_on_unsupported_cpu(vcpu))) {
                run->exit_reason = KVM_EXIT_FAIL_ENTRY;
                run->fail_entry.hardware_entry_failure_reason = KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED;
                run->fail_entry.cpu = smp_processor_id();
                *ret = 0;
                return true;
        }

        return kvm_request_pending(vcpu) ||
                        xfer_to_guest_mode_work_pending();
}

/*
 * Actually run the vCPU, entering an RCU extended quiescent state (EQS) while
 * the vCPU is running.
 *
 * This must be noinstr as instrumentation may make use of RCU, and this is not
 * safe during the EQS.
 */
static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
{
        int ret;

        guest_state_enter_irqoff();
        ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
        guest_state_exit_irqoff();

        return ret;
}

/**
 * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
 * @vcpu:       The VCPU pointer
 *
 * This function is called through the VCPU_RUN ioctl called from user space. It
 * will execute VM code in a loop until the time slice for the process is used
 * or some emulation is needed from user space in which case the function will
 * return with return value 0 and with the kvm_run structure filled in with the
 * required data for the requested emulation.
 */
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
        struct kvm_run *run = vcpu->run;
        int ret;

        if (run->exit_reason == KVM_EXIT_MMIO) {
                ret = kvm_handle_mmio_return(vcpu);
                if (ret)
                        return ret;
        }

        vcpu_load(vcpu);

        if (run->immediate_exit) {
                ret = -EINTR;
                goto out;
        }

        kvm_sigset_activate(vcpu);

        ret = 1;
        run->exit_reason = KVM_EXIT_UNKNOWN;
        run->flags = 0;
        while (ret > 0) {
                /*
                 * Check conditions before entering the guest
                 */
                ret = xfer_to_guest_mode_handle_work(vcpu);
                if (!ret)
                        ret = 1;

                if (ret > 0)
                        ret = check_vcpu_requests(vcpu);

                /*
                 * Preparing the interrupts to be injected also
                 * involves poking the GIC, which must be done in a
                 * non-preemptible context.
                 */
                preempt_disable();

                /*
                 * The VMID allocator only tracks active VMIDs per
                 * physical CPU, and therefore the VMID allocated may not be
                 * preserved on VMID roll-over if the task was preempted,
                 * making a thread's VMID inactive. So we need to call
                 * kvm_arm_vmid_update() in non-premptible context.
                 */
                if (kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid) &&
                    has_vhe())
                        __load_stage2(vcpu->arch.hw_mmu,
                                      vcpu->arch.hw_mmu->arch);

                kvm_pmu_flush_hwstate(vcpu);

                local_irq_disable();

                kvm_vgic_flush_hwstate(vcpu);

                kvm_pmu_update_vcpu_events(vcpu);

                /*
                 * Ensure we set mode to IN_GUEST_MODE after we disable
                 * interrupts and before the final VCPU requests check.
                 * See the comment in kvm_vcpu_exiting_guest_mode() and
                 * Documentation/virt/kvm/vcpu-requests.rst
                 */
                smp_store_mb(vcpu->mode, IN_GUEST_MODE);

                if (ret <= 0 || kvm_vcpu_exit_request(vcpu, &ret)) {
                        vcpu->mode = OUTSIDE_GUEST_MODE;
                        isb(); /* Ensure work in x_flush_hwstate is committed */
                        kvm_pmu_sync_hwstate(vcpu);
                        if (static_branch_unlikely(&userspace_irqchip_in_use))
                                kvm_timer_sync_user(vcpu);
                        kvm_vgic_sync_hwstate(vcpu);
                        local_irq_enable();
                        preempt_enable();
                        continue;
                }

                kvm_arm_setup_debug(vcpu);
                kvm_arch_vcpu_ctxflush_fp(vcpu);

                /**************************************************************
                 * Enter the guest
                 */
                trace_kvm_entry(*vcpu_pc(vcpu));
                guest_timing_enter_irqoff();

                ret = kvm_arm_vcpu_enter_exit(vcpu);

                vcpu->mode = OUTSIDE_GUEST_MODE;
                vcpu->stat.exits++;
                /*
                 * Back from guest
                 *************************************************************/

                kvm_arm_clear_debug(vcpu);

                /*
                 * We must sync the PMU state before the vgic state so
                 * that the vgic can properly sample the updated state of the
                 * interrupt line.
                 */
                kvm_pmu_sync_hwstate(vcpu);

                /*
                 * Sync the vgic state before syncing the timer state because
                 * the timer code needs to know if the virtual timer
                 * interrupts are active.
                 */
                kvm_vgic_sync_hwstate(vcpu);

                /*
                 * Sync the timer hardware state before enabling interrupts as
                 * we don't want vtimer interrupts to race with syncing the
                 * timer virtual interrupt state.
                 */
                if (static_branch_unlikely(&userspace_irqchip_in_use))
                        kvm_timer_sync_user(vcpu);

                kvm_arch_vcpu_ctxsync_fp(vcpu);

                /*
                 * We must ensure that any pending interrupts are taken before
                 * we exit guest timing so that timer ticks are accounted as
                 * guest time. Transiently unmask interrupts so that any
                 * pending interrupts are taken.
                 *
                 * Per ARM DDI 0487G.b section D1.13.4, an ISB (or other
                 * context synchronization event) is necessary to ensure that
                 * pending interrupts are taken.
                 */
                if (ARM_EXCEPTION_CODE(ret) == ARM_EXCEPTION_IRQ) {
                        local_irq_enable();
                        isb();
                        local_irq_disable();
                }

                guest_timing_exit_irqoff();

                local_irq_enable();

                trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));

                /* Exit types that need handling before we can be preempted */
                handle_exit_early(vcpu, ret);

                preempt_enable();

                /*
                 * The ARMv8 architecture doesn't give the hypervisor
                 * a mechanism to prevent a guest from dropping to AArch32 EL0
                 * if implemented by the CPU. If we spot the guest in such
                 * state and that we decided it wasn't supposed to do so (like
                 * with the asymmetric AArch32 case), return to userspace with
                 * a fatal error.
                 */
                if (vcpu_mode_is_bad_32bit(vcpu)) {
                        /*
                         * As we have caught the guest red-handed, decide that
                         * it isn't fit for purpose anymore by making the vcpu
                         * invalid. The VMM can try and fix it by issuing  a
                         * KVM_ARM_VCPU_INIT if it really wants to.
                         */
                        vcpu_clear_flag(vcpu, VCPU_INITIALIZED);
                        ret = ARM_EXCEPTION_IL;
                }

                ret = handle_exit(vcpu, ret);
        }

        /* Tell userspace about in-kernel device output levels */
        if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
                kvm_timer_update_run(vcpu);
                kvm_pmu_update_run(vcpu);
        }

        kvm_sigset_deactivate(vcpu);

out:
        /*
         * In the unlikely event that we are returning to userspace
         * with pending exceptions or PC adjustment, commit these
         * adjustments in order to give userspace a consistent view of
         * the vcpu state. Note that this relies on __kvm_adjust_pc()
         * being preempt-safe on VHE.
         */
        if (unlikely(vcpu_get_flag(vcpu, PENDING_EXCEPTION) ||
                     vcpu_get_flag(vcpu, INCREMENT_PC)))
                kvm_call_hyp(__kvm_adjust_pc, vcpu);

        vcpu_put(vcpu);
        return ret;
}

static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
{
        int bit_index;
        bool set;
        unsigned long *hcr;

        if (number == KVM_ARM_IRQ_CPU_IRQ)
                bit_index = __ffs(HCR_VI);
        else /* KVM_ARM_IRQ_CPU_FIQ */
                bit_index = __ffs(HCR_VF);

        hcr = vcpu_hcr(vcpu);
        if (level)
                set = test_and_set_bit(bit_index, hcr);
        else
                set = test_and_clear_bit(bit_index, hcr);

        /*
         * If we didn't change anything, no need to wake up or kick other CPUs
         */
        if (set == level)
                return 0;

        /*
         * The vcpu irq_lines field was updated, wake up sleeping VCPUs and
         * trigger a world-switch round on the running physical CPU to set the
         * virtual IRQ/FIQ fields in the HCR appropriately.
         */
        kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
        kvm_vcpu_kick(vcpu);

        return 0;
}

int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
                          bool line_status)
{
        u32 irq = irq_level->irq;
        unsigned int irq_type, vcpu_id, irq_num;
        struct kvm_vcpu *vcpu = NULL;
        bool level = irq_level->level;

        irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
        vcpu_id = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
        vcpu_id += ((irq >> KVM_ARM_IRQ_VCPU2_SHIFT) & KVM_ARM_IRQ_VCPU2_MASK) * (KVM_ARM_IRQ_VCPU_MASK + 1);
        irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;

        trace_kvm_irq_line(irq_type, vcpu_id, irq_num, irq_level->level);

        switch (irq_type) {
        case KVM_ARM_IRQ_TYPE_CPU:
                if (irqchip_in_kernel(kvm))
                        return -ENXIO;

                vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
                if (!vcpu)
                        return -EINVAL;

                if (irq_num > KVM_ARM_IRQ_CPU_FIQ)
                        return -EINVAL;

                return vcpu_interrupt_line(vcpu, irq_num, level);
        case KVM_ARM_IRQ_TYPE_PPI:
                if (!irqchip_in_kernel(kvm))
                        return -ENXIO;

                vcpu = kvm_get_vcpu_by_id(kvm, vcpu_id);
                if (!vcpu)
                        return -EINVAL;

                if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
                        return -EINVAL;

                return kvm_vgic_inject_irq(kvm, vcpu, irq_num, level, NULL);
        case KVM_ARM_IRQ_TYPE_SPI:
                if (!irqchip_in_kernel(kvm))
                        return -ENXIO;

                if (irq_num < VGIC_NR_PRIVATE_IRQS)
                        return -EINVAL;

                return kvm_vgic_inject_irq(kvm, NULL, irq_num, level, NULL);
        }

        return -EINVAL;
}

static unsigned long system_supported_vcpu_features(void)
{
        unsigned long features = KVM_VCPU_VALID_FEATURES;

        if (!cpus_have_final_cap(ARM64_HAS_32BIT_EL1))
                clear_bit(KVM_ARM_VCPU_EL1_32BIT, &features);

        if (!kvm_arm_support_pmu_v3())
                clear_bit(KVM_ARM_VCPU_PMU_V3, &features);

        if (!system_supports_sve())
                clear_bit(KVM_ARM_VCPU_SVE, &features);

        if (!system_has_full_ptr_auth()) {
                clear_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, &features);
                clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
        }

        if (!cpus_have_final_cap(ARM64_HAS_NESTED_VIRT))
                clear_bit(KVM_ARM_VCPU_HAS_EL2, &features);

        return features;
}

static int kvm_vcpu_init_check_features(struct kvm_vcpu *vcpu,
                                        const struct kvm_vcpu_init *init)
{
        unsigned long features = init->features[0];
        int i;

        if (features & ~KVM_VCPU_VALID_FEATURES)
                return -ENOENT;

        for (i = 1; i < ARRAY_SIZE(init->features); i++) {
                if (init->features[i])
                        return -ENOENT;
        }

        if (features & ~system_supported_vcpu_features())
                return -EINVAL;

        /*
         * For now make sure that both address/generic pointer authentication
         * features are requested by the userspace together.
         */
        if (test_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, &features) !=
            test_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features))
                return -EINVAL;

        /* Disallow NV+SVE for the time being */
        if (test_bit(KVM_ARM_VCPU_HAS_EL2, &features) &&
            test_bit(KVM_ARM_VCPU_SVE, &features))
                return -EINVAL;

        if (!test_bit(KVM_ARM_VCPU_EL1_32BIT, &features))
                return 0;

        /* MTE is incompatible with AArch32 */
        if (kvm_has_mte(vcpu->kvm))
                return -EINVAL;

        /* NV is incompatible with AArch32 */
        if (test_bit(KVM_ARM_VCPU_HAS_EL2, &features))
                return -EINVAL;

        return 0;
}

static bool kvm_vcpu_init_changed(struct kvm_vcpu *vcpu,
                                  const struct kvm_vcpu_init *init)
{
        unsigned long features = init->features[0];

        return !bitmap_equal(vcpu->kvm->arch.vcpu_features, &features,
                             KVM_VCPU_MAX_FEATURES);
}

static int kvm_setup_vcpu(struct kvm_vcpu *vcpu)
{
        struct kvm *kvm = vcpu->kvm;
        int ret = 0;

        /*
         * When the vCPU has a PMU, but no PMU is set for the guest
         * yet, set the default one.
         */
        if (kvm_vcpu_has_pmu(vcpu) && !kvm->arch.arm_pmu)
                ret = kvm_arm_set_default_pmu(kvm);

        return ret;
}

static int __kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
                                 const struct kvm_vcpu_init *init)
{
        unsigned long features = init->features[0];
        struct kvm *kvm = vcpu->kvm;
        int ret = -EINVAL;

        mutex_lock(&kvm->arch.config_lock);

        if (test_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags) &&
            kvm_vcpu_init_changed(vcpu, init))
                goto out_unlock;

        bitmap_copy(kvm->arch.vcpu_features, &features, KVM_VCPU_MAX_FEATURES);

        ret = kvm_setup_vcpu(vcpu);
        if (ret)
                goto out_unlock;

        /* Now we know what it is, we can reset it. */
        kvm_reset_vcpu(vcpu);

        set_bit(KVM_ARCH_FLAG_VCPU_FEATURES_CONFIGURED, &kvm->arch.flags);
        vcpu_set_flag(vcpu, VCPU_INITIALIZED);
        ret = 0;
out_unlock:
        mutex_unlock(&kvm->arch.config_lock);
        return ret;
}

static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
                               const struct kvm_vcpu_init *init)
{
        int ret;

        if (init->target != KVM_ARM_TARGET_GENERIC_V8 &&
            init->target != kvm_target_cpu())
                return -EINVAL;

        ret = kvm_vcpu_init_check_features(vcpu, init);
        if (ret)
                return ret;

        if (!kvm_vcpu_initialized(vcpu))
                return __kvm_vcpu_set_target(vcpu, init);

        if (kvm_vcpu_init_changed(vcpu, init))
                return -EINVAL;

        kvm_reset_vcpu(vcpu);
        return 0;
}

static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
                                         struct kvm_vcpu_init *init)
{
        bool power_off = false;
        int ret;

        /*
         * Treat the power-off vCPU feature as ephemeral. Clear the bit to avoid
         * reflecting it in the finalized feature set, thus limiting its scope
         * to a single KVM_ARM_VCPU_INIT call.
         */
        if (init->features[0] & BIT(KVM_ARM_VCPU_POWER_OFF)) {
                init->features[0] &= ~BIT(KVM_ARM_VCPU_POWER_OFF);
                power_off = true;
        }

        ret = kvm_vcpu_set_target(vcpu, init);
        if (ret)
                return ret;

        /*
         * Ensure a rebooted VM will fault in RAM pages and detect if the
         * guest MMU is turned off and flush the caches as needed.
         *
         * S2FWB enforces all memory accesses to RAM being cacheable,
         * ensuring that the data side is always coherent. We still
         * need to invalidate the I-cache though, as FWB does *not*
         * imply CTR_EL0.DIC.
         */
        if (vcpu_has_run_once(vcpu)) {
                if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
                        stage2_unmap_vm(vcpu->kvm);
                else
                        icache_inval_all_pou();
        }

        vcpu_reset_hcr(vcpu);
        vcpu->arch.cptr_el2 = kvm_get_reset_cptr_el2(vcpu);

        /*
         * Handle the "start in power-off" case.
         */
        spin_lock(&vcpu->arch.mp_state_lock);

        if (power_off)
                __kvm_arm_vcpu_power_off(vcpu);
        else
                WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE);

        spin_unlock(&vcpu->arch.mp_state_lock);

        return 0;
}

static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        int ret = -ENXIO;

        switch (attr->group) {
        default:
                ret = kvm_arm_vcpu_arch_set_attr(vcpu, attr);
                break;
        }

        return ret;
}

static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        int ret = -ENXIO;

        switch (attr->group) {
        default:
                ret = kvm_arm_vcpu_arch_get_attr(vcpu, attr);
                break;
        }

        return ret;
}

static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
                                 struct kvm_device_attr *attr)
{
        int ret = -ENXIO;

        switch (attr->group) {
        default:
                ret = kvm_arm_vcpu_arch_has_attr(vcpu, attr);
                break;
        }

        return ret;
}

static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
                                   struct kvm_vcpu_events *events)
{
        memset(events, 0, sizeof(*events));

        return __kvm_arm_vcpu_get_events(vcpu, events);
}

static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
                                   struct kvm_vcpu_events *events)
{
        int i;

        /* check whether the reserved field is zero */
        for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
                if (events->reserved[i])
                        return -EINVAL;

        /* check whether the pad field is zero */
        for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
                if (events->exception.pad[i])
                        return -EINVAL;

        return __kvm_arm_vcpu_set_events(vcpu, events);
}

long kvm_arch_vcpu_ioctl(struct file *filp,
                         unsigned int ioctl, unsigned long arg)
{
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
        struct kvm_device_attr attr;
        long r;

        switch (ioctl) {
        case KVM_ARM_VCPU_INIT: {
                struct kvm_vcpu_init init;

                r = -EFAULT;
                if (copy_from_user(&init, argp, sizeof(init)))
                        break;

                r = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init);
                break;
        }
        case KVM_SET_ONE_REG:
        case KVM_GET_ONE_REG: {
                struct kvm_one_reg reg;

                r = -ENOEXEC;
                if (unlikely(!kvm_vcpu_initialized(vcpu)))
                        break;

                r = -EFAULT;
                if (copy_from_user(&reg, argp, sizeof(reg)))
                        break;

                /*
                 * We could owe a reset due to PSCI. Handle the pending reset
                 * here to ensure userspace register accesses are ordered after
                 * the reset.
                 */
                if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
                        kvm_reset_vcpu(vcpu);

                if (ioctl == KVM_SET_ONE_REG)
                        r = kvm_arm_set_reg(vcpu, &reg);
                else
                        r = kvm_arm_get_reg(vcpu, &reg);
                break;
        }
        case KVM_GET_REG_LIST: {
                struct kvm_reg_list __user *user_list = argp;
                struct kvm_reg_list reg_list;
                unsigned n;

                r = -ENOEXEC;
                if (unlikely(!kvm_vcpu_initialized(vcpu)))
                        break;

                r = -EPERM;
                if (!kvm_arm_vcpu_is_finalized(vcpu))
                        break;

                r = -EFAULT;
                if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
                        break;
                n = reg_list.n;
                reg_list.n = kvm_arm_num_regs(vcpu);
                if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
                        break;
                r = -E2BIG;
                if (n < reg_list.n)
                        break;
                r = kvm_arm_copy_reg_indices(vcpu, user_list->reg);
                break;
        }
        case KVM_SET_DEVICE_ATTR: {
                r = -EFAULT;
                if (copy_from_user(&attr, argp, sizeof(attr)))
                        break;
                r = kvm_arm_vcpu_set_attr(vcpu, &attr);
                break;
        }
        case KVM_GET_DEVICE_ATTR: {
                r = -EFAULT;
                if (copy_from_user(&attr, argp, sizeof(attr)))
                        break;
                r = kvm_arm_vcpu_get_attr(vcpu, &attr);
                break;
        }
        case KVM_HAS_DEVICE_ATTR: {
                r = -EFAULT;
                if (copy_from_user(&attr, argp, sizeof(attr)))
                        break;
                r = kvm_arm_vcpu_has_attr(vcpu, &attr);
                break;
        }
        case KVM_GET_VCPU_EVENTS: {
                struct kvm_vcpu_events events;

                if (kvm_arm_vcpu_get_events(vcpu, &events))
                        return -EINVAL;

                if (copy_to_user(argp, &events, sizeof(events)))
                        return -EFAULT;

                return 0;
        }
        case KVM_SET_VCPU_EVENTS: {
                struct kvm_vcpu_events events;

                if (copy_from_user(&events, argp, sizeof(events)))
                        return -EFAULT;

                return kvm_arm_vcpu_set_events(vcpu, &events);
        }
        case KVM_ARM_VCPU_FINALIZE: {
                int what;

                if (!kvm_vcpu_initialized(vcpu))
                        return -ENOEXEC;

                if (get_user(what, (const int __user *)argp))
                        return -EFAULT;

                return kvm_arm_vcpu_finalize(vcpu, what);
        }
        default:
                r = -EINVAL;
        }

        return r;
}

void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
{

}

static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
                                        struct kvm_arm_device_addr *dev_addr)
{
        switch (FIELD_GET(KVM_ARM_DEVICE_ID_MASK, dev_addr->id)) {
        case KVM_ARM_DEVICE_VGIC_V2:
                if (!vgic_present)
                        return -ENXIO;
                return kvm_set_legacy_vgic_v2_addr(kvm, dev_addr);
        default:
                return -ENODEV;
        }
}

static int kvm_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
{
        switch (attr->group) {
        case KVM_ARM_VM_SMCCC_CTRL:
                return kvm_vm_smccc_has_attr(kvm, attr);
        default:
                return -ENXIO;
        }
}

static int kvm_vm_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
{
        switch (attr->group) {
        case KVM_ARM_VM_SMCCC_CTRL:
                return kvm_vm_smccc_set_attr(kvm, attr);
        default:
                return -ENXIO;
        }
}

int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
{
        struct kvm *kvm = filp->private_data;
        void __user *argp = (void __user *)arg;
        struct kvm_device_attr attr;

        switch (ioctl) {
        case KVM_CREATE_IRQCHIP: {
                int ret;
                if (!vgic_present)
                        return -ENXIO;
                mutex_lock(&kvm->lock);
                ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
                mutex_unlock(&kvm->lock);
                return ret;
        }
        case KVM_ARM_SET_DEVICE_ADDR: {
                struct kvm_arm_device_addr dev_addr;

                if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
                        return -EFAULT;
                return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
        }
        case KVM_ARM_PREFERRED_TARGET: {
                struct kvm_vcpu_init init = {
                        .target = KVM_ARM_TARGET_GENERIC_V8,
                };

                if (copy_to_user(argp, &init, sizeof(init)))
                        return -EFAULT;

                return 0;
        }
        case KVM_ARM_MTE_COPY_TAGS: {
                struct kvm_arm_copy_mte_tags copy_tags;

                if (copy_from_user(&copy_tags, argp, sizeof(copy_tags)))
                        return -EFAULT;
                return kvm_vm_ioctl_mte_copy_tags(kvm, &copy_tags);
        }
        case KVM_ARM_SET_COUNTER_OFFSET: {
                struct kvm_arm_counter_offset offset;

                if (copy_from_user(&offset, argp, sizeof(offset)))
                        return -EFAULT;
                return kvm_vm_ioctl_set_counter_offset(kvm, &offset);
        }
        case KVM_HAS_DEVICE_ATTR: {
                if (copy_from_user(&attr, argp, sizeof(attr)))
                        return -EFAULT;

                return kvm_vm_has_attr(kvm, &attr);
        }
        case KVM_SET_DEVICE_ATTR: {
                if (copy_from_user(&attr, argp, sizeof(attr)))
                        return -EFAULT;

                return kvm_vm_set_attr(kvm, &attr);
        }
        case KVM_ARM_GET_REG_WRITABLE_MASKS: {
                struct reg_mask_range range;

                if (copy_from_user(&range, argp, sizeof(range)))
                        return -EFAULT;
                return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range);
        }
        default:
                return -EINVAL;
        }
}

/* unlocks vcpus from @vcpu_lock_idx and smaller */
static void unlock_vcpus(struct kvm *kvm, int vcpu_lock_idx)
{
        struct kvm_vcpu *tmp_vcpu;

        for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
                tmp_vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
                mutex_unlock(&tmp_vcpu->mutex);
        }
}

void unlock_all_vcpus(struct kvm *kvm)
{
        lockdep_assert_held(&kvm->lock);

        unlock_vcpus(kvm, atomic_read(&kvm->online_vcpus) - 1);
}

/* Returns true if all vcpus were locked, false otherwise */
bool lock_all_vcpus(struct kvm *kvm)
{
        struct kvm_vcpu *tmp_vcpu;
        unsigned long c;

        lockdep_assert_held(&kvm->lock);

        /*
         * Any time a vcpu is in an ioctl (including running), the
         * core KVM code tries to grab the vcpu->mutex.
         *
         * By grabbing the vcpu->mutex of all VCPUs we ensure that no
         * other VCPUs can fiddle with the state while we access it.
         */
        kvm_for_each_vcpu(c, tmp_vcpu, kvm) {
                if (!mutex_trylock(&tmp_vcpu->mutex)) {
                        unlock_vcpus(kvm, c - 1);
                        return false;
                }
        }

        return true;
}

static unsigned long nvhe_percpu_size(void)
{
        return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) -
                (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_start);
}

static unsigned long nvhe_percpu_order(void)
{
        unsigned long size = nvhe_percpu_size();

        return size ? get_order(size) : 0;
}

/* A lookup table holding the hypervisor VA for each vector slot */
static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS];

static void kvm_init_vector_slot(void *base, enum arm64_hyp_spectre_vector slot)
{
        hyp_spectre_vector_selector[slot] = __kvm_vector_slot2addr(base, slot);
}

static int kvm_init_vector_slots(void)
{
        int err;
        void *base;

        base = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
        kvm_init_vector_slot(base, HYP_VECTOR_DIRECT);

        base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
        kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT);

        if (kvm_system_needs_idmapped_vectors() &&
            !is_protected_kvm_enabled()) {
                err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs),
                                               __BP_HARDEN_HYP_VECS_SZ, &base);
                if (err)
                        return err;
        }

        kvm_init_vector_slot(base, HYP_VECTOR_INDIRECT);
        kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_INDIRECT);
        return 0;
}

static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits)
{
        struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
        u64 mmfr0 = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
        unsigned long tcr;

        /*
         * Calculate the raw per-cpu offset without a translation from the
         * kernel's mapping to the linear mapping, and store it in tpidr_el2
         * so that we can use adr_l to access per-cpu variables in EL2.
         * Also drop the KASAN tag which gets in the way...
         */
        params->tpidr_el2 = (unsigned long)kasan_reset_tag(per_cpu_ptr_nvhe_sym(__per_cpu_start, cpu)) -
                            (unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));

        params->mair_el2 = read_sysreg(mair_el1);

        tcr = read_sysreg(tcr_el1);
        if (cpus_have_final_cap(ARM64_KVM_HVHE)) {
                tcr |= TCR_EPD1_MASK;
        } else {
                tcr &= TCR_EL2_MASK;
                tcr |= TCR_EL2_RES1;
        }
        tcr &= ~TCR_T0SZ_MASK;
        tcr |= TCR_T0SZ(hyp_va_bits);
        tcr &= ~TCR_EL2_PS_MASK;
        tcr |= FIELD_PREP(TCR_EL2_PS_MASK, kvm_get_parange(mmfr0));
        if (kvm_lpa2_is_enabled())
                tcr |= TCR_EL2_DS;
        params->tcr_el2 = tcr;

        params->pgd_pa = kvm_mmu_get_httbr();
        if (is_protected_kvm_enabled())
                params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
        else
                params->hcr_el2 = HCR_HOST_NVHE_FLAGS;
        if (cpus_have_final_cap(ARM64_KVM_HVHE))
                params->hcr_el2 |= HCR_E2H;
        params->vttbr = params->vtcr = 0;

        /*
         * Flush the init params from the data cache because the struct will
         * be read while the MMU is off.
         */
        kvm_flush_dcache_to_poc(params, sizeof(*params));
}

static void hyp_install_host_vector(void)
{
        struct kvm_nvhe_init_params *params;
        struct arm_smccc_res res;

        /* Switch from the HYP stub to our own HYP init vector */
        __hyp_set_vectors(kvm_get_idmap_vector());

        /*
         * Call initialization code, and switch to the full blown HYP code.
         * If the cpucaps haven't been finalized yet, something has gone very
         * wrong, and hyp will crash and burn when it uses any
         * cpus_have_*_cap() wrapper.
         */
        BUG_ON(!system_capabilities_finalized());
        params = this_cpu_ptr_nvhe_sym(kvm_init_params);
        arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
        WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
}

static void cpu_init_hyp_mode(void)
{
        hyp_install_host_vector();

        /*
         * Disabling SSBD on a non-VHE system requires us to enable SSBS
         * at EL2.
         */
        if (this_cpu_has_cap(ARM64_SSBS) &&
            arm64_get_spectre_v4_state() == SPECTRE_VULNERABLE) {
                kvm_call_hyp_nvhe(__kvm_enable_ssbs);
        }
}

static void cpu_hyp_reset(void)
{
        if (!is_kernel_in_hyp_mode())
                __hyp_reset_vectors();
}

/*
 * EL2 vectors can be mapped and rerouted in a number of ways,
 * depending on the kernel configuration and CPU present:
 *
 * - If the CPU is affected by Spectre-v2, the hardening sequence is
 *   placed in one of the vector slots, which is executed before jumping
 *   to the real vectors.
 *
 * - If the CPU also has the ARM64_SPECTRE_V3A cap, the slot
 *   containing the hardening sequence is mapped next to the idmap page,
 *   and executed before jumping to the real vectors.
 *
 * - If the CPU only has the ARM64_SPECTRE_V3A cap, then an
 *   empty slot is selected, mapped next to the idmap page, and
 *   executed before jumping to the real vectors.
 *
 * Note that ARM64_SPECTRE_V3A is somewhat incompatible with
 * VHE, as we don't have hypervisor-specific mappings. If the system
 * is VHE and yet selects this capability, it will be ignored.
 */
static void cpu_set_hyp_vector(void)
{
        struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
        void *vector = hyp_spectre_vector_selector[data->slot];

        if (!is_protected_kvm_enabled())
                *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector;
        else
                kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot);
}

static void cpu_hyp_init_context(void)
{
        kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);

        if (!is_kernel_in_hyp_mode())
                cpu_init_hyp_mode();
}

static void cpu_hyp_init_features(void)
{
        cpu_set_hyp_vector();
        kvm_arm_init_debug();

        if (is_kernel_in_hyp_mode())
                kvm_timer_init_vhe();

        if (vgic_present)
                kvm_vgic_init_cpu_hardware();
}

static void cpu_hyp_reinit(void)
{
        cpu_hyp_reset();
        cpu_hyp_init_context();
        cpu_hyp_init_features();
}

static void cpu_hyp_init(void *discard)
{
        if (!__this_cpu_read(kvm_hyp_initialized)) {
                cpu_hyp_reinit();
                __this_cpu_write(kvm_hyp_initialized, 1);
        }
}

static void cpu_hyp_uninit(void *discard)
{
        if (__this_cpu_read(kvm_hyp_initialized)) {
                cpu_hyp_reset();
                __this_cpu_write(kvm_hyp_initialized, 0);
        }
}

int kvm_arch_hardware_enable(void)
{
        /*
         * Most calls to this function are made with migration
         * disabled, but not with preemption disabled. The former is
         * enough to ensure correctness, but most of the helpers
         * expect the later and will throw a tantrum otherwise.
         */
        preempt_disable();

        cpu_hyp_init(NULL);

        kvm_vgic_cpu_up();
        kvm_timer_cpu_up();

        preempt_enable();

        return 0;
}

void kvm_arch_hardware_disable(void)
{
        kvm_timer_cpu_down();
        kvm_vgic_cpu_down();

        if (!is_protected_kvm_enabled())
                cpu_hyp_uninit(NULL);
}

#ifdef CONFIG_CPU_PM
static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
                                    unsigned long cmd,
                                    void *v)
{
        /*
         * kvm_hyp_initialized is left with its old value over
         * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
         * re-enable hyp.
         */
        switch (cmd) {
        case CPU_PM_ENTER:
                if (__this_cpu_read(kvm_hyp_initialized))
                        /*
                         * don't update kvm_hyp_initialized here
                         * so that the hyp will be re-enabled
                         * when we resume. See below.
                         */
                        cpu_hyp_reset();

                return NOTIFY_OK;
        case CPU_PM_ENTER_FAILED:
        case CPU_PM_EXIT:
                if (__this_cpu_read(kvm_hyp_initialized))
                        /* The hyp was enabled before suspend. */
                        cpu_hyp_reinit();

                return NOTIFY_OK;

        default:
                return NOTIFY_DONE;
        }
}

static struct notifier_block hyp_init_cpu_pm_nb = {
        .notifier_call = hyp_init_cpu_pm_notifier,
};

static void __init hyp_cpu_pm_init(void)
{
        if (!is_protected_kvm_enabled())
                cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
}
static void __init hyp_cpu_pm_exit(void)
{
        if (!is_protected_kvm_enabled())
                cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
}
#else
static inline void __init hyp_cpu_pm_init(void)
{
}
static inline void __init hyp_cpu_pm_exit(void)
{
}
#endif

static void __init init_cpu_logical_map(void)
{
        unsigned int cpu;

        /*
         * Copy the MPIDR <-> logical CPU ID mapping to hyp.
         * Only copy the set of online CPUs whose features have been checked
         * against the finalized system capabilities. The hypervisor will not
         * allow any other CPUs from the `possible` set to boot.
         */
        for_each_online_cpu(cpu)
                hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu);
}

#define init_psci_0_1_impl_state(config, what)  \
        config.psci_0_1_ ## what ## _implemented = psci_ops.what

static bool __init init_psci_relay(void)
{
        /*
         * If PSCI has not been initialized, protected KVM cannot install
         * itself on newly booted CPUs.
         */
        if (!psci_ops.get_version) {
                kvm_err("Cannot initialize protected mode without PSCI\n");
                return false;
        }

        kvm_host_psci_config.version = psci_ops.get_version();
        kvm_host_psci_config.smccc_version = arm_smccc_get_version();

        if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
                kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
                init_psci_0_1_impl_state(kvm_host_psci_config, cpu_suspend);
                init_psci_0_1_impl_state(kvm_host_psci_config, cpu_on);
                init_psci_0_1_impl_state(kvm_host_psci_config, cpu_off);
                init_psci_0_1_impl_state(kvm_host_psci_config, migrate);
        }
        return true;
}

static int __init init_subsystems(void)
{
        int err = 0;

        /*
         * Enable hardware so that subsystem initialisation can access EL2.
         */
        on_each_cpu(cpu_hyp_init, NULL, 1);

        /*
         * Register CPU lower-power notifier
         */
        hyp_cpu_pm_init();

        /*
         * Init HYP view of VGIC
         */
        err = kvm_vgic_hyp_init();
        switch (err) {
        case 0:
                vgic_present = true;
                break;
        case -ENODEV:
        case -ENXIO:
                vgic_present = false;
                err = 0;
                break;
        default:
                goto out;
        }

        /*
         * Init HYP architected timer support
         */
        err = kvm_timer_hyp_init(vgic_present);
        if (err)
                goto out;

        kvm_register_perf_callbacks(NULL);

out:
        if (err)
                hyp_cpu_pm_exit();

        if (err || !is_protected_kvm_enabled())
                on_each_cpu(cpu_hyp_uninit, NULL, 1);

        return err;
}

static void __init teardown_subsystems(void)
{
        kvm_unregister_perf_callbacks();
        hyp_cpu_pm_exit();
}

static void __init teardown_hyp_mode(void)
{
        int cpu;

        free_hyp_pgds();
        for_each_possible_cpu(cpu) {
                free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
                free_pages(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu], nvhe_percpu_order());
        }
}

static int __init do_pkvm_init(u32 hyp_va_bits)
{
        void *per_cpu_base = kvm_ksym_ref(kvm_nvhe_sym(kvm_arm_hyp_percpu_base));
        int ret;

        preempt_disable();
        cpu_hyp_init_context();
        ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size,
                                num_possible_cpus(), kern_hyp_va(per_cpu_base),
                                hyp_va_bits);
        cpu_hyp_init_features();

        /*
         * The stub hypercalls are now disabled, so set our local flag to
         * prevent a later re-init attempt in kvm_arch_hardware_enable().
         */
        __this_cpu_write(kvm_hyp_initialized, 1);
        preempt_enable();

        return ret;
}

static u64 get_hyp_id_aa64pfr0_el1(void)
{
        /*
         * Track whether the system isn't affected by spectre/meltdown in the
         * hypervisor's view of id_aa64pfr0_el1, used for protected VMs.
         * Although this is per-CPU, we make it global for simplicity, e.g., not
         * to have to worry about vcpu migration.
         *
         * Unlike for non-protected VMs, userspace cannot override this for
         * protected VMs.
         */
        u64 val = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);

        val &= ~(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) |
                 ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3));

        val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2),
                          arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED);
        val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3),
                          arm64_get_meltdown_state() == SPECTRE_UNAFFECTED);

        return val;
}

static void kvm_hyp_init_symbols(void)
{
        kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = get_hyp_id_aa64pfr0_el1();
        kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
        kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
        kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
        kvm_nvhe_sym(id_aa64isar2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
        kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
        kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
        kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1);
        kvm_nvhe_sym(id_aa64smfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64SMFR0_EL1);
        kvm_nvhe_sym(__icache_flags) = __icache_flags;
        kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits;
}

static int __init kvm_hyp_init_protection(u32 hyp_va_bits)
{
        void *addr = phys_to_virt(hyp_mem_base);
        int ret;

        ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
        if (ret)
                return ret;

        ret = do_pkvm_init(hyp_va_bits);
        if (ret)
                return ret;

        free_hyp_pgds();

        return 0;
}

static void pkvm_hyp_init_ptrauth(void)
{
        struct kvm_cpu_context *hyp_ctxt;
        int cpu;

        for_each_possible_cpu(cpu) {
                hyp_ctxt = per_cpu_ptr_nvhe_sym(kvm_hyp_ctxt, cpu);
                hyp_ctxt->sys_regs[APIAKEYLO_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APIAKEYHI_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APIBKEYLO_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APIBKEYHI_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APDAKEYLO_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APDAKEYHI_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APDBKEYLO_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APDBKEYHI_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APGAKEYLO_EL1] = get_random_long();
                hyp_ctxt->sys_regs[APGAKEYHI_EL1] = get_random_long();
        }
}

/* Inits Hyp-mode on all online CPUs */
static int __init init_hyp_mode(void)
{
        u32 hyp_va_bits;
        int cpu;
        int err = -ENOMEM;

        /*
         * The protected Hyp-mode cannot be initialized if the memory pool
         * allocation has failed.
         */
        if (is_protected_kvm_enabled() && !hyp_mem_base)
                goto out_err;

        /*
         * Allocate Hyp PGD and setup Hyp identity mapping
         */
        err = kvm_mmu_init(&hyp_va_bits);
        if (err)
                goto out_err;

        /*
         * Allocate stack pages for Hypervisor-mode
         */
        for_each_possible_cpu(cpu) {
                unsigned long stack_page;

                stack_page = __get_free_page(GFP_KERNEL);
                if (!stack_page) {
                        err = -ENOMEM;
                        goto out_err;
                }

                per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
        }

        /*
         * Allocate and initialize pages for Hypervisor-mode percpu regions.
         */
        for_each_possible_cpu(cpu) {
                struct page *page;
                void *page_addr;

                page = alloc_pages(GFP_KERNEL, nvhe_percpu_order());
                if (!page) {
                        err = -ENOMEM;
                        goto out_err;
                }

                page_addr = page_address(page);
                memcpy(page_addr, CHOOSE_NVHE_SYM(__per_cpu_start), nvhe_percpu_size());
                kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu] = (unsigned long)page_addr;
        }

        /*
         * Map the Hyp-code called directly from the host
         */
        err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start),
                                  kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC);
        if (err) {
                kvm_err("Cannot map world-switch code\n");
                goto out_err;
        }

        err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
                                  kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
        if (err) {
                kvm_err("Cannot map .hyp.rodata section\n");
                goto out_err;
        }

        err = create_hyp_mappings(kvm_ksym_ref(__start_rodata),
                                  kvm_ksym_ref(__end_rodata), PAGE_HYP_RO);
        if (err) {
                kvm_err("Cannot map rodata section\n");
                goto out_err;
        }

        /*
         * .hyp.bss is guaranteed to be placed at the beginning of the .bss
         * section thanks to an assertion in the linker script. Map it RW and
         * the rest of .bss RO.
         */
        err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_start),
                                  kvm_ksym_ref(__hyp_bss_end), PAGE_HYP);
        if (err) {
                kvm_err("Cannot map hyp bss section: %d\n", err);
                goto out_err;
        }

        err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_end),
                                  kvm_ksym_ref(__bss_stop), PAGE_HYP_RO);
        if (err) {
                kvm_err("Cannot map bss section\n");
                goto out_err;
        }

        /*
         * Map the Hyp stack pages
         */
        for_each_possible_cpu(cpu) {
                struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
                char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);

                err = create_hyp_stack(__pa(stack_page), &params->stack_hyp_va);
                if (err) {
                        kvm_err("Cannot map hyp stack\n");
                        goto out_err;
                }

                /*
                 * Save the stack PA in nvhe_init_params. This will be needed
                 * to recreate the stack mapping in protected nVHE mode.
                 * __hyp_pa() won't do the right thing there, since the stack
                 * has been mapped in the flexible private VA space.
                 */
                params->stack_pa = __pa(stack_page);
        }

        for_each_possible_cpu(cpu) {
                char *percpu_begin = (char *)kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];
                char *percpu_end = percpu_begin + nvhe_percpu_size();

                /* Map Hyp percpu pages */
                err = create_hyp_mappings(percpu_begin, percpu_end, PAGE_HYP);
                if (err) {
                        kvm_err("Cannot map hyp percpu region\n");
                        goto out_err;
                }

                /* Prepare the CPU initialization parameters */
                cpu_prepare_hyp_mode(cpu, hyp_va_bits);
        }

        kvm_hyp_init_symbols();

        if (is_protected_kvm_enabled()) {
                if (IS_ENABLED(CONFIG_ARM64_PTR_AUTH_KERNEL) &&
                    cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH))
                        pkvm_hyp_init_ptrauth();

                init_cpu_logical_map();

                if (!init_psci_relay()) {
                        err = -ENODEV;
                        goto out_err;
                }

                err = kvm_hyp_init_protection(hyp_va_bits);
                if (err) {
                        kvm_err("Failed to init hyp memory protection\n");
                        goto out_err;
                }
        }

        return 0;

out_err:
        teardown_hyp_mode();
        kvm_err("error initializing Hyp mode: %d\n", err);
        return err;
}

struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
{
        struct kvm_vcpu *vcpu;
        unsigned long i;

        mpidr &= MPIDR_HWID_BITMASK;

        if (kvm->arch.mpidr_data) {
                u16 idx = kvm_mpidr_index(kvm->arch.mpidr_data, mpidr);

                vcpu = kvm_get_vcpu(kvm,
                                    kvm->arch.mpidr_data->cmpidr_to_idx[idx]);
                if (mpidr != kvm_vcpu_get_mpidr_aff(vcpu))
                        vcpu = NULL;

                return vcpu;
        }

        kvm_for_each_vcpu(i, vcpu, kvm) {
                if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
                        return vcpu;
        }
        return NULL;
}

bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
{
        return irqchip_in_kernel(kvm);
}

bool kvm_arch_has_irq_bypass(void)
{
        return true;
}

int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
                                      struct irq_bypass_producer *prod)
{
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);

        return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
                                          &irqfd->irq_entry);
}
void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
                                      struct irq_bypass_producer *prod)
{
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);

        kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
                                     &irqfd->irq_entry);
}

void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
{
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);

        kvm_arm_halt_guest(irqfd->kvm);
}

void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
{
        struct kvm_kernel_irqfd *irqfd =
                container_of(cons, struct kvm_kernel_irqfd, consumer);

        kvm_arm_resume_guest(irqfd->kvm);
}

/* Initialize Hyp-mode and memory mappings on all CPUs */
static __init int kvm_arm_init(void)
{
        int err;
        bool in_hyp_mode;

        if (!is_hyp_mode_available()) {
                kvm_info("HYP mode not available\n");
                return -ENODEV;
        }

        if (kvm_get_mode() == KVM_MODE_NONE) {
                kvm_info("KVM disabled from command line\n");
                return -ENODEV;
        }

        err = kvm_sys_reg_table_init();
        if (err) {
                kvm_info("Error initializing system register tables");
                return err;
        }

        in_hyp_mode = is_kernel_in_hyp_mode();

        if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
            cpus_have_final_cap(ARM64_WORKAROUND_1508412))
                kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
                         "Only trusted guests should be used on this system.\n");

        err = kvm_set_ipa_limit();
        if (err)
                return err;

        err = kvm_arm_init_sve();
        if (err)
                return err;

        err = kvm_arm_vmid_alloc_init();
        if (err) {
                kvm_err("Failed to initialize VMID allocator.\n");
                return err;
        }

        if (!in_hyp_mode) {
                err = init_hyp_mode();
                if (err)
                        goto out_err;
        }

        err = kvm_init_vector_slots();
        if (err) {
                kvm_err("Cannot initialise vector slots\n");
                goto out_hyp;
        }

        err = init_subsystems();
        if (err)
                goto out_hyp;

        if (is_protected_kvm_enabled()) {
                kvm_info("Protected nVHE mode initialized successfully\n");
        } else if (in_hyp_mode) {
                kvm_info("VHE mode initialized successfully\n");
        } else {
                kvm_info("Hyp mode initialized successfully\n");
        }

        /*
         * FIXME: Do something reasonable if kvm_init() fails after pKVM
         * hypervisor protection is finalized.
         */
        err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
        if (err)
                goto out_subs;

        kvm_arm_initialised = true;

        return 0;

out_subs:
        teardown_subsystems();
out_hyp:
        if (!in_hyp_mode)
                teardown_hyp_mode();
out_err:
        kvm_arm_vmid_alloc_free();
        return err;
}

static int __init early_kvm_mode_cfg(char *arg)
{
        if (!arg)
                return -EINVAL;

        if (strcmp(arg, "none") == 0) {
                kvm_mode = KVM_MODE_NONE;
                return 0;
        }

        if (!is_hyp_mode_available()) {
                pr_warn_once("KVM is not available. Ignoring kvm-arm.mode\n");
                return 0;
        }

        if (strcmp(arg, "protected") == 0) {
                if (!is_kernel_in_hyp_mode())
                        kvm_mode = KVM_MODE_PROTECTED;
                else
                        pr_warn_once("Protected KVM not available with VHE\n");

                return 0;
        }

        if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode())) {
                kvm_mode = KVM_MODE_DEFAULT;
                return 0;
        }

        if (strcmp(arg, "nested") == 0 && !WARN_ON(!is_kernel_in_hyp_mode())) {
                kvm_mode = KVM_MODE_NV;
                return 0;
        }

        return -EINVAL;
}
early_param("kvm-arm.mode", early_kvm_mode_cfg);

enum kvm_mode kvm_get_mode(void)
{
        return kvm_mode;
}

module_init(kvm_arm_init);