// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2020 - Google Inc
 * Author: Andrew Scull <ascull@google.com>
 */

#include <hyp/adjust_pc.h>
#include <hyp/switch.h>

#include <asm/pgtable-types.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_host.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>

#include <nvhe/ffa.h>
#include <nvhe/mem_protect.h>
#include <nvhe/mm.h>
#include <nvhe/pkvm.h>
#include <nvhe/trap_handler.h>

DEFINE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);

void __kvm_hyp_host_forward_smc(struct kvm_cpu_context *host_ctxt);

static void __hyp_sve_save_guest(struct kvm_vcpu *vcpu)
{
        __vcpu_assign_sys_reg(vcpu, ZCR_EL1, read_sysreg_el1(SYS_ZCR));
        /*
         * On saving/restoring guest sve state, always use the maximum VL for
         * the guest. The layout of the data when saving the sve state depends
         * on the VL, so use a consistent (i.e., the maximum) guest VL.
         */
        sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
        __sve_save_state(vcpu_sve_pffr(vcpu), &vcpu->arch.ctxt.fp_regs.fpsr, true);
        write_sysreg_s(sve_vq_from_vl(kvm_host_sve_max_vl) - 1, SYS_ZCR_EL2);
}

static void __hyp_sve_restore_host(void)
{
        struct cpu_sve_state *sve_state = *host_data_ptr(sve_state);

        /*
         * On saving/restoring host sve state, always use the maximum VL for
         * the host. The layout of the data when saving the sve state depends
         * on the VL, so use a consistent (i.e., the maximum) host VL.
         *
         * Note that this constrains the PE to the maximum shared VL
         * that was discovered, if we wish to use larger VLs this will
         * need to be revisited.
         */
        write_sysreg_s(sve_vq_from_vl(kvm_host_sve_max_vl) - 1, SYS_ZCR_EL2);
        __sve_restore_state(sve_state->sve_regs + sve_ffr_offset(kvm_host_sve_max_vl),
                            &sve_state->fpsr,
                            true);
        write_sysreg_el1(sve_state->zcr_el1, SYS_ZCR);
}

static void fpsimd_sve_flush(void)
{
        *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
}

static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
{
        bool has_fpmr;

        if (!guest_owns_fp_regs())
                return;

        /*
         * Traps have been disabled by __deactivate_cptr_traps(), but there
         * hasn't necessarily been a context synchronization event yet.
         */
        isb();

        if (vcpu_has_sve(vcpu))
                __hyp_sve_save_guest(vcpu);
        else
                __fpsimd_save_state(&vcpu->arch.ctxt.fp_regs);

        has_fpmr = kvm_has_fpmr(kern_hyp_va(vcpu->kvm));
        if (has_fpmr)
                __vcpu_assign_sys_reg(vcpu, FPMR, read_sysreg_s(SYS_FPMR));

        if (system_supports_sve())
                __hyp_sve_restore_host();
        else
                __fpsimd_restore_state(host_data_ptr(host_ctxt.fp_regs));

        if (has_fpmr)
                write_sysreg_s(*host_data_ptr(fpmr), SYS_FPMR);

        *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
}

static void flush_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu)
{
        struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;

        hyp_vcpu->vcpu.arch.debug_owner = host_vcpu->arch.debug_owner;

        if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu))
                hyp_vcpu->vcpu.arch.vcpu_debug_state = host_vcpu->arch.vcpu_debug_state;
        else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu))
                hyp_vcpu->vcpu.arch.external_debug_state = host_vcpu->arch.external_debug_state;
}

static void sync_debug_state(struct pkvm_hyp_vcpu *hyp_vcpu)
{
        struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;

        if (kvm_guest_owns_debug_regs(&hyp_vcpu->vcpu))
                host_vcpu->arch.vcpu_debug_state = hyp_vcpu->vcpu.arch.vcpu_debug_state;
        else if (kvm_host_owns_debug_regs(&hyp_vcpu->vcpu))
                host_vcpu->arch.external_debug_state = hyp_vcpu->vcpu.arch.external_debug_state;
}

static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
{
        struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;

        fpsimd_sve_flush();
        flush_debug_state(hyp_vcpu);

        hyp_vcpu->vcpu.arch.ctxt        = host_vcpu->arch.ctxt;

        hyp_vcpu->vcpu.arch.mdcr_el2    = host_vcpu->arch.mdcr_el2;
        hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE);
        hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) &
                                                 (HCR_TWI | HCR_TWE);

        hyp_vcpu->vcpu.arch.iflags      = host_vcpu->arch.iflags;

        hyp_vcpu->vcpu.arch.vsesr_el2   = host_vcpu->arch.vsesr_el2;

        hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3;
}

static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
{
        struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;
        struct vgic_v3_cpu_if *hyp_cpu_if = &hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3;
        struct vgic_v3_cpu_if *host_cpu_if = &host_vcpu->arch.vgic_cpu.vgic_v3;
        unsigned int i;

        fpsimd_sve_sync(&hyp_vcpu->vcpu);
        sync_debug_state(hyp_vcpu);

        host_vcpu->arch.ctxt            = hyp_vcpu->vcpu.arch.ctxt;

        host_vcpu->arch.hcr_el2         = hyp_vcpu->vcpu.arch.hcr_el2;

        host_vcpu->arch.fault           = hyp_vcpu->vcpu.arch.fault;

        host_vcpu->arch.iflags          = hyp_vcpu->vcpu.arch.iflags;

        host_cpu_if->vgic_hcr           = hyp_cpu_if->vgic_hcr;
        host_cpu_if->vgic_vmcr          = hyp_cpu_if->vgic_vmcr;
        for (i = 0; i < hyp_cpu_if->used_lrs; ++i)
                host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i];
}

static void handle___pkvm_vcpu_load(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(unsigned int, vcpu_idx, host_ctxt, 2);
        DECLARE_REG(u64, hcr_el2, host_ctxt, 3);
        struct pkvm_hyp_vcpu *hyp_vcpu;

        if (!is_protected_kvm_enabled())
                return;

        hyp_vcpu = pkvm_load_hyp_vcpu(handle, vcpu_idx);
        if (!hyp_vcpu)
                return;

        if (pkvm_hyp_vcpu_is_protected(hyp_vcpu)) {
                /* Propagate WFx trapping flags */
                hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWE | HCR_TWI);
                hyp_vcpu->vcpu.arch.hcr_el2 |= hcr_el2 & (HCR_TWE | HCR_TWI);
        } else {
                memcpy(&hyp_vcpu->vcpu.arch.fgt, hyp_vcpu->host_vcpu->arch.fgt,
                       sizeof(hyp_vcpu->vcpu.arch.fgt));
        }
}

static void handle___pkvm_vcpu_put(struct kvm_cpu_context *host_ctxt)
{
        struct pkvm_hyp_vcpu *hyp_vcpu;

        if (!is_protected_kvm_enabled())
                return;

        hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
        if (hyp_vcpu)
                pkvm_put_hyp_vcpu(hyp_vcpu);
}

static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1);
        int ret;

        if (unlikely(is_protected_kvm_enabled())) {
                struct pkvm_hyp_vcpu *hyp_vcpu = pkvm_get_loaded_hyp_vcpu();

                /*
                 * KVM (and pKVM) doesn't support SME guests for now, and
                 * ensures that SME features aren't enabled in pstate when
                 * loading a vcpu. Therefore, if SME features enabled the host
                 * is misbehaving.
                 */
                if (unlikely(system_supports_sme() && read_sysreg_s(SYS_SVCR))) {
                        ret = -EINVAL;
                        goto out;
                }

                if (!hyp_vcpu) {
                        ret = -EINVAL;
                        goto out;
                }

                flush_hyp_vcpu(hyp_vcpu);

                ret = __kvm_vcpu_run(&hyp_vcpu->vcpu);

                sync_hyp_vcpu(hyp_vcpu);
        } else {
                struct kvm_vcpu *vcpu = kern_hyp_va(host_vcpu);

                /* The host is fully trusted, run its vCPU directly. */
                fpsimd_lazy_switch_to_guest(vcpu);
                ret = __kvm_vcpu_run(vcpu);
                fpsimd_lazy_switch_to_host(vcpu);
        }
out:
        cpu_reg(host_ctxt, 1) =  ret;
}

static int pkvm_refill_memcache(struct pkvm_hyp_vcpu *hyp_vcpu)
{
        struct kvm_vcpu *host_vcpu = hyp_vcpu->host_vcpu;

        return refill_memcache(&hyp_vcpu->vcpu.arch.pkvm_memcache,
                               host_vcpu->arch.pkvm_memcache.nr_pages,
                               &host_vcpu->arch.pkvm_memcache);
}

static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, pfn, host_ctxt, 1);
        DECLARE_REG(u64, gfn, host_ctxt, 2);
        DECLARE_REG(u64, nr_pages, host_ctxt, 3);
        DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 4);
        struct pkvm_hyp_vcpu *hyp_vcpu;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
        if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
                goto out;

        ret = pkvm_refill_memcache(hyp_vcpu);
        if (ret)
                goto out;

        ret = __pkvm_host_share_guest(pfn, gfn, nr_pages, hyp_vcpu, prot);
out:
        cpu_reg(host_ctxt, 1) =  ret;
}

static void handle___pkvm_host_unshare_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(u64, gfn, host_ctxt, 2);
        DECLARE_REG(u64, nr_pages, host_ctxt, 3);
        struct pkvm_hyp_vm *hyp_vm;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vm = get_np_pkvm_hyp_vm(handle);
        if (!hyp_vm)
                goto out;

        ret = __pkvm_host_unshare_guest(gfn, nr_pages, hyp_vm);
        put_pkvm_hyp_vm(hyp_vm);
out:
        cpu_reg(host_ctxt, 1) =  ret;
}

static void handle___pkvm_host_relax_perms_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, gfn, host_ctxt, 1);
        DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 2);
        struct pkvm_hyp_vcpu *hyp_vcpu;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
        if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
                goto out;

        ret = __pkvm_host_relax_perms_guest(gfn, hyp_vcpu, prot);
out:
        cpu_reg(host_ctxt, 1) = ret;
}

static void handle___pkvm_host_wrprotect_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(u64, gfn, host_ctxt, 2);
        DECLARE_REG(u64, nr_pages, host_ctxt, 3);
        struct pkvm_hyp_vm *hyp_vm;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vm = get_np_pkvm_hyp_vm(handle);
        if (!hyp_vm)
                goto out;

        ret = __pkvm_host_wrprotect_guest(gfn, nr_pages, hyp_vm);
        put_pkvm_hyp_vm(hyp_vm);
out:
        cpu_reg(host_ctxt, 1) = ret;
}

static void handle___pkvm_host_test_clear_young_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(u64, gfn, host_ctxt, 2);
        DECLARE_REG(u64, nr_pages, host_ctxt, 3);
        DECLARE_REG(bool, mkold, host_ctxt, 4);
        struct pkvm_hyp_vm *hyp_vm;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vm = get_np_pkvm_hyp_vm(handle);
        if (!hyp_vm)
                goto out;

        ret = __pkvm_host_test_clear_young_guest(gfn, nr_pages, mkold, hyp_vm);
        put_pkvm_hyp_vm(hyp_vm);
out:
        cpu_reg(host_ctxt, 1) = ret;
}

static void handle___pkvm_host_mkyoung_guest(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, gfn, host_ctxt, 1);
        struct pkvm_hyp_vcpu *hyp_vcpu;
        int ret = -EINVAL;

        if (!is_protected_kvm_enabled())
                goto out;

        hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
        if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
                goto out;

        ret = __pkvm_host_mkyoung_guest(gfn, hyp_vcpu);
out:
        cpu_reg(host_ctxt, 1) =  ret;
}

static void handle___kvm_adjust_pc(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_vcpu *, vcpu, host_ctxt, 1);

        __kvm_adjust_pc(kern_hyp_va(vcpu));
}

static void handle___kvm_flush_vm_context(struct kvm_cpu_context *host_ctxt)
{
        __kvm_flush_vm_context();
}

static void handle___kvm_tlb_flush_vmid_ipa(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
        DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
        DECLARE_REG(int, level, host_ctxt, 3);

        __kvm_tlb_flush_vmid_ipa(kern_hyp_va(mmu), ipa, level);
}

static void handle___kvm_tlb_flush_vmid_ipa_nsh(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
        DECLARE_REG(phys_addr_t, ipa, host_ctxt, 2);
        DECLARE_REG(int, level, host_ctxt, 3);

        __kvm_tlb_flush_vmid_ipa_nsh(kern_hyp_va(mmu), ipa, level);
}

static void
handle___kvm_tlb_flush_vmid_range(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);
        DECLARE_REG(phys_addr_t, start, host_ctxt, 2);
        DECLARE_REG(unsigned long, pages, host_ctxt, 3);

        __kvm_tlb_flush_vmid_range(kern_hyp_va(mmu), start, pages);
}

static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);

        __kvm_tlb_flush_vmid(kern_hyp_va(mmu));
}

static void handle___pkvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        struct pkvm_hyp_vm *hyp_vm;

        if (!is_protected_kvm_enabled())
                return;

        hyp_vm = get_np_pkvm_hyp_vm(handle);
        if (!hyp_vm)
                return;

        __kvm_tlb_flush_vmid(&hyp_vm->kvm.arch.mmu);
        put_pkvm_hyp_vm(hyp_vm);
}

static void handle___kvm_flush_cpu_context(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm_s2_mmu *, mmu, host_ctxt, 1);

        __kvm_flush_cpu_context(kern_hyp_va(mmu));
}

static void handle___kvm_timer_set_cntvoff(struct kvm_cpu_context *host_ctxt)
{
        __kvm_timer_set_cntvoff(cpu_reg(host_ctxt, 1));
}

static void handle___kvm_enable_ssbs(struct kvm_cpu_context *host_ctxt)
{
        u64 tmp;

        tmp = read_sysreg_el2(SYS_SCTLR);
        tmp |= SCTLR_ELx_DSSBS;
        write_sysreg_el2(tmp, SYS_SCTLR);
}

static void handle___vgic_v3_get_gic_config(struct kvm_cpu_context *host_ctxt)
{
        cpu_reg(host_ctxt, 1) = __vgic_v3_get_gic_config();
}

static void handle___vgic_v3_init_lrs(struct kvm_cpu_context *host_ctxt)
{
        __vgic_v3_init_lrs();
}

static void handle___vgic_v3_save_aprs(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);

        __vgic_v3_save_aprs(kern_hyp_va(cpu_if));
}

static void handle___vgic_v3_restore_vmcr_aprs(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct vgic_v3_cpu_if *, cpu_if, host_ctxt, 1);

        __vgic_v3_restore_vmcr_aprs(kern_hyp_va(cpu_if));
}

static void handle___pkvm_init(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
        DECLARE_REG(unsigned long, size, host_ctxt, 2);
        DECLARE_REG(unsigned long, nr_cpus, host_ctxt, 3);
        DECLARE_REG(unsigned long *, per_cpu_base, host_ctxt, 4);
        DECLARE_REG(u32, hyp_va_bits, host_ctxt, 5);

        /*
         * __pkvm_init() will return only if an error occurred, otherwise it
         * will tail-call in __pkvm_init_finalise() which will have to deal
         * with the host context directly.
         */
        cpu_reg(host_ctxt, 1) = __pkvm_init(phys, size, nr_cpus, per_cpu_base,
                                            hyp_va_bits);
}

static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(enum arm64_hyp_spectre_vector, slot, host_ctxt, 1);

        cpu_reg(host_ctxt, 1) = pkvm_cpu_set_vector(slot);
}

static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, pfn, host_ctxt, 1);

        cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn);
}

static void handle___pkvm_host_unshare_hyp(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, pfn, host_ctxt, 1);

        cpu_reg(host_ctxt, 1) = __pkvm_host_unshare_hyp(pfn);
}

static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(phys_addr_t, phys, host_ctxt, 1);
        DECLARE_REG(size_t, size, host_ctxt, 2);
        DECLARE_REG(enum kvm_pgtable_prot, prot, host_ctxt, 3);

        /*
         * __pkvm_create_private_mapping() populates a pointer with the
         * hypervisor start address of the allocation.
         *
         * However, handle___pkvm_create_private_mapping() hypercall crosses the
         * EL1/EL2 boundary so the pointer would not be valid in this context.
         *
         * Instead pass the allocation address as the return value (or return
         * ERR_PTR() on failure).
         */
        unsigned long haddr;
        int err = __pkvm_create_private_mapping(phys, size, prot, &haddr);

        if (err)
                haddr = (unsigned long)ERR_PTR(err);

        cpu_reg(host_ctxt, 1) = haddr;
}

static void handle___pkvm_prot_finalize(struct kvm_cpu_context *host_ctxt)
{
        cpu_reg(host_ctxt, 1) = __pkvm_prot_finalize();
}

static void handle___pkvm_reserve_vm(struct kvm_cpu_context *host_ctxt)
{
        cpu_reg(host_ctxt, 1) = __pkvm_reserve_vm();
}

static void handle___pkvm_unreserve_vm(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);

        __pkvm_unreserve_vm(handle);
}

static void handle___pkvm_init_vm(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(struct kvm *, host_kvm, host_ctxt, 1);
        DECLARE_REG(unsigned long, vm_hva, host_ctxt, 2);
        DECLARE_REG(unsigned long, pgd_hva, host_ctxt, 3);

        host_kvm = kern_hyp_va(host_kvm);
        cpu_reg(host_ctxt, 1) = __pkvm_init_vm(host_kvm, vm_hva, pgd_hva);
}

static void handle___pkvm_init_vcpu(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
        DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 2);
        DECLARE_REG(unsigned long, vcpu_hva, host_ctxt, 3);

        host_vcpu = kern_hyp_va(host_vcpu);
        cpu_reg(host_ctxt, 1) = __pkvm_init_vcpu(handle, host_vcpu, vcpu_hva);
}

static void handle___pkvm_teardown_vm(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);

        cpu_reg(host_ctxt, 1) = __pkvm_teardown_vm(handle);
}

typedef void (*hcall_t)(struct kvm_cpu_context *);

#define HANDLE_FUNC(x)  [__KVM_HOST_SMCCC_FUNC_##x] = (hcall_t)handle_##x

static const hcall_t host_hcall[] = {
        /* ___kvm_hyp_init */
        HANDLE_FUNC(__pkvm_init),
        HANDLE_FUNC(__pkvm_create_private_mapping),
        HANDLE_FUNC(__pkvm_cpu_set_vector),
        HANDLE_FUNC(__kvm_enable_ssbs),
        HANDLE_FUNC(__vgic_v3_init_lrs),
        HANDLE_FUNC(__vgic_v3_get_gic_config),
        HANDLE_FUNC(__pkvm_prot_finalize),

        HANDLE_FUNC(__pkvm_host_share_hyp),
        HANDLE_FUNC(__pkvm_host_unshare_hyp),
        HANDLE_FUNC(__pkvm_host_share_guest),
        HANDLE_FUNC(__pkvm_host_unshare_guest),
        HANDLE_FUNC(__pkvm_host_relax_perms_guest),
        HANDLE_FUNC(__pkvm_host_wrprotect_guest),
        HANDLE_FUNC(__pkvm_host_test_clear_young_guest),
        HANDLE_FUNC(__pkvm_host_mkyoung_guest),
        HANDLE_FUNC(__kvm_adjust_pc),
        HANDLE_FUNC(__kvm_vcpu_run),
        HANDLE_FUNC(__kvm_flush_vm_context),
        HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa),
        HANDLE_FUNC(__kvm_tlb_flush_vmid_ipa_nsh),
        HANDLE_FUNC(__kvm_tlb_flush_vmid),
        HANDLE_FUNC(__kvm_tlb_flush_vmid_range),
        HANDLE_FUNC(__kvm_flush_cpu_context),
        HANDLE_FUNC(__kvm_timer_set_cntvoff),
        HANDLE_FUNC(__vgic_v3_save_aprs),
        HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
        HANDLE_FUNC(__pkvm_reserve_vm),
        HANDLE_FUNC(__pkvm_unreserve_vm),
        HANDLE_FUNC(__pkvm_init_vm),
        HANDLE_FUNC(__pkvm_init_vcpu),
        HANDLE_FUNC(__pkvm_teardown_vm),
        HANDLE_FUNC(__pkvm_vcpu_load),
        HANDLE_FUNC(__pkvm_vcpu_put),
        HANDLE_FUNC(__pkvm_tlb_flush_vmid),
};

static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(unsigned long, id, host_ctxt, 0);
        unsigned long hcall_min = 0;
        hcall_t hfn;

        /*
         * If pKVM has been initialised then reject any calls to the
         * early "privileged" hypercalls. Note that we cannot reject
         * calls to __pkvm_prot_finalize for two reasons: (1) The static
         * key used to determine initialisation must be toggled prior to
         * finalisation and (2) finalisation is performed on a per-CPU
         * basis. This is all fine, however, since __pkvm_prot_finalize
         * returns -EPERM after the first call for a given CPU.
         */
        if (static_branch_unlikely(&kvm_protected_mode_initialized))
                hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize;

        id &= ~ARM_SMCCC_CALL_HINTS;
        id -= KVM_HOST_SMCCC_ID(0);

        if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall)))
                goto inval;

        hfn = host_hcall[id];
        if (unlikely(!hfn))
                goto inval;

        cpu_reg(host_ctxt, 0) = SMCCC_RET_SUCCESS;
        hfn(host_ctxt);

        return;
inval:
        cpu_reg(host_ctxt, 0) = SMCCC_RET_NOT_SUPPORTED;
}

static void default_host_smc_handler(struct kvm_cpu_context *host_ctxt)
{
        __kvm_hyp_host_forward_smc(host_ctxt);
}

static void handle_host_smc(struct kvm_cpu_context *host_ctxt)
{
        DECLARE_REG(u64, func_id, host_ctxt, 0);
        bool handled;

        func_id &= ~ARM_SMCCC_CALL_HINTS;

        handled = kvm_host_psci_handler(host_ctxt, func_id);
        if (!handled)
                handled = kvm_host_ffa_handler(host_ctxt, func_id);
        if (!handled)
                default_host_smc_handler(host_ctxt);

        /* SMC was trapped, move ELR past the current PC. */
        kvm_skip_host_instr();
}

/*
 * Inject an Undefined Instruction exception into the host.
 *
 * This is open-coded to allow control over PSTATE construction without
 * complicating the generic exception entry helpers.
 */
static void inject_undef64(void)
{
        u64 spsr_mask, vbar, sctlr, old_spsr, new_spsr, esr, offset;

        spsr_mask = PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT | PSR_DIT_BIT | PSR_PAN_BIT;

        vbar = read_sysreg_el1(SYS_VBAR);
        sctlr = read_sysreg_el1(SYS_SCTLR);
        old_spsr = read_sysreg_el2(SYS_SPSR);

        new_spsr = old_spsr & spsr_mask;
        new_spsr |= PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT;
        new_spsr |= PSR_MODE_EL1h;

        if (!(sctlr & SCTLR_EL1_SPAN))
                new_spsr |= PSR_PAN_BIT;

        if (sctlr & SCTLR_ELx_DSSBS)
                new_spsr |= PSR_SSBS_BIT;

        if (system_supports_mte())
                new_spsr |= PSR_TCO_BIT;

        esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT) | ESR_ELx_IL;
        offset = CURRENT_EL_SP_ELx_VECTOR + except_type_sync;

        write_sysreg_el1(esr, SYS_ESR);
        write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR);
        write_sysreg_el1(old_spsr, SYS_SPSR);
        write_sysreg_el2(vbar + offset, SYS_ELR);
        write_sysreg_el2(new_spsr, SYS_SPSR);
}

static bool handle_host_mte(u64 esr)
{
        switch (esr_sys64_to_sysreg(esr)) {
        case SYS_RGSR_EL1:
        case SYS_GCR_EL1:
        case SYS_TFSR_EL1:
        case SYS_TFSRE0_EL1:
                /* If we're here for any reason other than MTE, it's a bug. */
                if (read_sysreg(HCR_EL2) & HCR_ATA)
                        return false;
                break;
        case SYS_GMID_EL1:
                /* If we're here for any reason other than MTE, it's a bug. */
                if (!(read_sysreg(HCR_EL2) & HCR_TID5))
                        return false;
                break;
        default:
                return false;
        }

        inject_undef64();
        return true;
}

void handle_trap(struct kvm_cpu_context *host_ctxt)
{
        u64 esr = read_sysreg_el2(SYS_ESR);

        switch (ESR_ELx_EC(esr)) {
        case ESR_ELx_EC_HVC64:
                handle_host_hcall(host_ctxt);
                break;
        case ESR_ELx_EC_SMC64:
                handle_host_smc(host_ctxt);
                break;
        case ESR_ELx_EC_IABT_LOW:
        case ESR_ELx_EC_DABT_LOW:
                handle_host_mem_abort(host_ctxt);
                break;
        case ESR_ELx_EC_SYS64:
                if (handle_host_mte(esr))
                        break;
                fallthrough;
        default:
                BUG();
        }
}