// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012,2013 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * Derived from arch/arm/kvm/coproc.c:
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Authors: Rusty Russell <rusty@rustcorp.com.au>
 *          Christoffer Dall <c.dall@virtualopensystems.com>
 */

#include <linux/bitfield.h>
#include <linux/bsearch.h>
#include <linux/kvm_host.h>
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/uaccess.h>

#include <asm/cacheflush.h>
#include <asm/cputype.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/perf_event.h>
#include <asm/sysreg.h>

#include <trace/events/kvm.h>

#include "sys_regs.h"

#include "trace.h"

/*
 * All of this file is extremely similar to the ARM coproc.c, but the
 * types are different. My gut feeling is that it should be pretty
 * easy to merge, but that would be an ABI breakage -- again. VFP
 * would also need to be abstracted.
 *
 * For AArch32, we only take care of what is being trapped. Anything
 * that has to do with init and userspace access has to go via the
 * 64bit interface.
 */

#define reg_to_encoding(x)                                              \
        sys_reg((u32)(x)->Op0, (u32)(x)->Op1,                           \
                (u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)

static bool read_from_write_only(struct kvm_vcpu *vcpu,
                                 struct sys_reg_params *params,
                                 const struct sys_reg_desc *r)
{
        WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n");
        print_sys_reg_instr(params);
        kvm_inject_undefined(vcpu);
        return false;
}

static bool write_to_read_only(struct kvm_vcpu *vcpu,
                               struct sys_reg_params *params,
                               const struct sys_reg_desc *r)
{
        WARN_ONCE(1, "Unexpected sys_reg write to read-only register\n");
        print_sys_reg_instr(params);
        kvm_inject_undefined(vcpu);
        return false;
}

u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
{
        u64 val = 0x8badf00d8badf00d;

        if (vcpu->arch.sysregs_loaded_on_cpu &&
            __vcpu_read_sys_reg_from_cpu(reg, &val))
                return val;

        return __vcpu_sys_reg(vcpu, reg);
}

void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
{
        if (vcpu->arch.sysregs_loaded_on_cpu &&
            __vcpu_write_sys_reg_to_cpu(val, reg))
                return;

         __vcpu_sys_reg(vcpu, reg) = val;
}

/* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
static u32 cache_levels;

/* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
#define CSSELR_MAX 14

/* Which cache CCSIDR represents depends on CSSELR value. */
static u32 get_ccsidr(u32 csselr)
{
        u32 ccsidr;

        /* Make sure noone else changes CSSELR during this! */
        local_irq_disable();
        write_sysreg(csselr, csselr_el1);
        isb();
        ccsidr = read_sysreg(ccsidr_el1);
        local_irq_enable();

        return ccsidr;
}

/*
 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
 */
static bool access_dcsw(struct kvm_vcpu *vcpu,
                        struct sys_reg_params *p,
                        const struct sys_reg_desc *r)
{
        if (!p->is_write)
                return read_from_write_only(vcpu, p, r);

        /*
         * Only track S/W ops if we don't have FWB. It still indicates
         * that the guest is a bit broken (S/W operations should only
         * be done by firmware, knowing that there is only a single
         * CPU left in the system, and certainly not from non-secure
         * software).
         */
        if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB))
                kvm_set_way_flush(vcpu);

        return true;
}

static void get_access_mask(const struct sys_reg_desc *r, u64 *mask, u64 *shift)
{
        switch (r->aarch32_map) {
        case AA32_LO:
                *mask = GENMASK_ULL(31, 0);
                *shift = 0;
                break;
        case AA32_HI:
                *mask = GENMASK_ULL(63, 32);
                *shift = 32;
                break;
        default:
                *mask = GENMASK_ULL(63, 0);
                *shift = 0;
                break;
        }
}

/*
 * Generic accessor for VM registers. Only called as long as HCR_TVM
 * is set. If the guest enables the MMU, we stop trapping the VM
 * sys_regs and leave it in complete control of the caches.
 */
static bool access_vm_reg(struct kvm_vcpu *vcpu,
                          struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        bool was_enabled = vcpu_has_cache_enabled(vcpu);
        u64 val, mask, shift;

        BUG_ON(!p->is_write);

        get_access_mask(r, &mask, &shift);

        if (~mask) {
                val = vcpu_read_sys_reg(vcpu, r->reg);
                val &= ~mask;
        } else {
                val = 0;
        }

        val |= (p->regval & (mask >> shift)) << shift;
        vcpu_write_sys_reg(vcpu, val, r->reg);

        kvm_toggle_cache(vcpu, was_enabled);
        return true;
}

static bool access_actlr(struct kvm_vcpu *vcpu,
                         struct sys_reg_params *p,
                         const struct sys_reg_desc *r)
{
        u64 mask, shift;

        if (p->is_write)
                return ignore_write(vcpu, p);

        get_access_mask(r, &mask, &shift);
        p->regval = (vcpu_read_sys_reg(vcpu, r->reg) & mask) >> shift;

        return true;
}

/*
 * Trap handler for the GICv3 SGI generation system register.
 * Forward the request to the VGIC emulation.
 * The cp15_64 code makes sure this automatically works
 * for both AArch64 and AArch32 accesses.
 */
static bool access_gic_sgi(struct kvm_vcpu *vcpu,
                           struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        bool g1;

        if (!p->is_write)
                return read_from_write_only(vcpu, p, r);

        /*
         * In a system where GICD_CTLR.DS=1, a ICC_SGI0R_EL1 access generates
         * Group0 SGIs only, while ICC_SGI1R_EL1 can generate either group,
         * depending on the SGI configuration. ICC_ASGI1R_EL1 is effectively
         * equivalent to ICC_SGI0R_EL1, as there is no "alternative" secure
         * group.
         */
        if (p->Op0 == 0) {              /* AArch32 */
                switch (p->Op1) {
                default:                /* Keep GCC quiet */
                case 0:                 /* ICC_SGI1R */
                        g1 = true;
                        break;
                case 1:                 /* ICC_ASGI1R */
                case 2:                 /* ICC_SGI0R */
                        g1 = false;
                        break;
                }
        } else {                        /* AArch64 */
                switch (p->Op2) {
                default:                /* Keep GCC quiet */
                case 5:                 /* ICC_SGI1R_EL1 */
                        g1 = true;
                        break;
                case 6:                 /* ICC_ASGI1R_EL1 */
                case 7:                 /* ICC_SGI0R_EL1 */
                        g1 = false;
                        break;
                }
        }

        vgic_v3_dispatch_sgi(vcpu, p->regval, g1);

        return true;
}

static bool access_gic_sre(struct kvm_vcpu *vcpu,
                           struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        if (p->is_write)
                return ignore_write(vcpu, p);

        p->regval = vcpu->arch.vgic_cpu.vgic_v3.vgic_sre;
        return true;
}

static bool trap_raz_wi(struct kvm_vcpu *vcpu,
                        struct sys_reg_params *p,
                        const struct sys_reg_desc *r)
{
        if (p->is_write)
                return ignore_write(vcpu, p);
        else
                return read_zero(vcpu, p);
}

/*
 * ARMv8.1 mandates at least a trivial LORegion implementation, where all the
 * RW registers are RES0 (which we can implement as RAZ/WI). On an ARMv8.0
 * system, these registers should UNDEF. LORID_EL1 being a RO register, we
 * treat it separately.
 */
static bool trap_loregion(struct kvm_vcpu *vcpu,
                          struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        u64 val = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
        u32 sr = reg_to_encoding(r);

        if (!(val & (0xfUL << ID_AA64MMFR1_LOR_SHIFT))) {
                kvm_inject_undefined(vcpu);
                return false;
        }

        if (p->is_write && sr == SYS_LORID_EL1)
                return write_to_read_only(vcpu, p, r);

        return trap_raz_wi(vcpu, p, r);
}

static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
                           struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        if (p->is_write) {
                return ignore_write(vcpu, p);
        } else {
                p->regval = (1 << 3);
                return true;
        }
}

static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
                                   struct sys_reg_params *p,
                                   const struct sys_reg_desc *r)
{
        if (p->is_write) {
                return ignore_write(vcpu, p);
        } else {
                p->regval = read_sysreg(dbgauthstatus_el1);
                return true;
        }
}

/*
 * We want to avoid world-switching all the DBG registers all the
 * time:
 * 
 * - If we've touched any debug register, it is likely that we're
 *   going to touch more of them. It then makes sense to disable the
 *   traps and start doing the save/restore dance
 * - If debug is active (DBG_MDSCR_KDE or DBG_MDSCR_MDE set), it is
 *   then mandatory to save/restore the registers, as the guest
 *   depends on them.
 * 
 * For this, we use a DIRTY bit, indicating the guest has modified the
 * debug registers, used as follow:
 *
 * On guest entry:
 * - If the dirty bit is set (because we're coming back from trapping),
 *   disable the traps, save host registers, restore guest registers.
 * - If debug is actively in use (DBG_MDSCR_KDE or DBG_MDSCR_MDE set),
 *   set the dirty bit, disable the traps, save host registers,
 *   restore guest registers.
 * - Otherwise, enable the traps
 *
 * On guest exit:
 * - If the dirty bit is set, save guest registers, restore host
 *   registers and clear the dirty bit. This ensure that the host can
 *   now use the debug registers.
 */
static bool trap_debug_regs(struct kvm_vcpu *vcpu,
                            struct sys_reg_params *p,
                            const struct sys_reg_desc *r)
{
        if (p->is_write) {
                vcpu_write_sys_reg(vcpu, p->regval, r->reg);
                vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
        } else {
                p->regval = vcpu_read_sys_reg(vcpu, r->reg);
        }

        trace_trap_reg(__func__, r->reg, p->is_write, p->regval);

        return true;
}

/*
 * reg_to_dbg/dbg_to_reg
 *
 * A 32 bit write to a debug register leave top bits alone
 * A 32 bit read from a debug register only returns the bottom bits
 *
 * All writes will set the KVM_ARM64_DEBUG_DIRTY flag to ensure the
 * hyp.S code switches between host and guest values in future.
 */
static void reg_to_dbg(struct kvm_vcpu *vcpu,
                       struct sys_reg_params *p,
                       const struct sys_reg_desc *rd,
                       u64 *dbg_reg)
{
        u64 mask, shift, val;

        get_access_mask(rd, &mask, &shift);

        val = *dbg_reg;
        val &= ~mask;
        val |= (p->regval & (mask >> shift)) << shift;
        *dbg_reg = val;

        vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
}

static void dbg_to_reg(struct kvm_vcpu *vcpu,
                       struct sys_reg_params *p,
                       const struct sys_reg_desc *rd,
                       u64 *dbg_reg)
{
        u64 mask, shift;

        get_access_mask(rd, &mask, &shift);
        p->regval = (*dbg_reg & mask) >> shift;
}

static bool trap_bvr(struct kvm_vcpu *vcpu,
                     struct sys_reg_params *p,
                     const struct sys_reg_desc *rd)
{
        u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];

        if (p->is_write)
                reg_to_dbg(vcpu, p, rd, dbg_reg);
        else
                dbg_to_reg(vcpu, p, rd, dbg_reg);

        trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg);

        return true;
}

static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];

        if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static int get_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
        const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm];

        if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static void reset_bvr(struct kvm_vcpu *vcpu,
                      const struct sys_reg_desc *rd)
{
        vcpu->arch.vcpu_debug_state.dbg_bvr[rd->CRm] = rd->val;
}

static bool trap_bcr(struct kvm_vcpu *vcpu,
                     struct sys_reg_params *p,
                     const struct sys_reg_desc *rd)
{
        u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];

        if (p->is_write)
                reg_to_dbg(vcpu, p, rd, dbg_reg);
        else
                dbg_to_reg(vcpu, p, rd, dbg_reg);

        trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg);

        return true;
}

static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];

        if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;

        return 0;
}

static int get_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
        const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm];

        if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static void reset_bcr(struct kvm_vcpu *vcpu,
                      const struct sys_reg_desc *rd)
{
        vcpu->arch.vcpu_debug_state.dbg_bcr[rd->CRm] = rd->val;
}

static bool trap_wvr(struct kvm_vcpu *vcpu,
                     struct sys_reg_params *p,
                     const struct sys_reg_desc *rd)
{
        u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];

        if (p->is_write)
                reg_to_dbg(vcpu, p, rd, dbg_reg);
        else
                dbg_to_reg(vcpu, p, rd, dbg_reg);

        trace_trap_reg(__func__, rd->CRm, p->is_write,
                vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm]);

        return true;
}

static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];

        if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static int get_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
        const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm];

        if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static void reset_wvr(struct kvm_vcpu *vcpu,
                      const struct sys_reg_desc *rd)
{
        vcpu->arch.vcpu_debug_state.dbg_wvr[rd->CRm] = rd->val;
}

static bool trap_wcr(struct kvm_vcpu *vcpu,
                     struct sys_reg_params *p,
                     const struct sys_reg_desc *rd)
{
        u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];

        if (p->is_write)
                reg_to_dbg(vcpu, p, rd, dbg_reg);
        else
                dbg_to_reg(vcpu, p, rd, dbg_reg);

        trace_trap_reg(__func__, rd->CRm, p->is_write, *dbg_reg);

        return true;
}

static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];

        if (copy_from_user(r, uaddr, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static int get_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
        const struct kvm_one_reg *reg, void __user *uaddr)
{
        __u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm];

        if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
                return -EFAULT;
        return 0;
}

static void reset_wcr(struct kvm_vcpu *vcpu,
                      const struct sys_reg_desc *rd)
{
        vcpu->arch.vcpu_debug_state.dbg_wcr[rd->CRm] = rd->val;
}

static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
        u64 amair = read_sysreg(amair_el1);
        vcpu_write_sys_reg(vcpu, amair, AMAIR_EL1);
}

static void reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
        u64 actlr = read_sysreg(actlr_el1);
        vcpu_write_sys_reg(vcpu, actlr, ACTLR_EL1);
}

static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
        u64 mpidr;

        /*
         * Map the vcpu_id into the first three affinity level fields of
         * the MPIDR. We limit the number of VCPUs in level 0 due to a
         * limitation to 16 CPUs in that level in the ICC_SGIxR registers
         * of the GICv3 to be able to address each CPU directly when
         * sending IPIs.
         */
        mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0);
        mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1);
        mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2);
        vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1);
}

static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu,
                                   const struct sys_reg_desc *r)
{
        if (kvm_vcpu_has_pmu(vcpu))
                return 0;

        return REG_HIDDEN;
}

static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
        u64 pmcr, val;

        /* No PMU available, PMCR_EL0 may UNDEF... */
        if (!kvm_arm_support_pmu_v3())
                return;

        pmcr = read_sysreg(pmcr_el0);
        /*
         * Writable bits of PMCR_EL0 (ARMV8_PMU_PMCR_MASK) are reset to UNKNOWN
         * except PMCR.E resetting to zero.
         */
        val = ((pmcr & ~ARMV8_PMU_PMCR_MASK)
               | (ARMV8_PMU_PMCR_MASK & 0xdecafbad)) & (~ARMV8_PMU_PMCR_E);
        if (!system_supports_32bit_el0())
                val |= ARMV8_PMU_PMCR_LC;
        __vcpu_sys_reg(vcpu, r->reg) = val;
}

static bool check_pmu_access_disabled(struct kvm_vcpu *vcpu, u64 flags)
{
        u64 reg = __vcpu_sys_reg(vcpu, PMUSERENR_EL0);
        bool enabled = (reg & flags) || vcpu_mode_priv(vcpu);

        if (!enabled)
                kvm_inject_undefined(vcpu);

        return !enabled;
}

static bool pmu_access_el0_disabled(struct kvm_vcpu *vcpu)
{
        return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_EN);
}

static bool pmu_write_swinc_el0_disabled(struct kvm_vcpu *vcpu)
{
        return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_SW | ARMV8_PMU_USERENR_EN);
}

static bool pmu_access_cycle_counter_el0_disabled(struct kvm_vcpu *vcpu)
{
        return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_CR | ARMV8_PMU_USERENR_EN);
}

static bool pmu_access_event_counter_el0_disabled(struct kvm_vcpu *vcpu)
{
        return check_pmu_access_disabled(vcpu, ARMV8_PMU_USERENR_ER | ARMV8_PMU_USERENR_EN);
}

static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                        const struct sys_reg_desc *r)
{
        u64 val;

        if (pmu_access_el0_disabled(vcpu))
                return false;

        if (p->is_write) {
                /* Only update writeable bits of PMCR */
                val = __vcpu_sys_reg(vcpu, PMCR_EL0);
                val &= ~ARMV8_PMU_PMCR_MASK;
                val |= p->regval & ARMV8_PMU_PMCR_MASK;
                if (!system_supports_32bit_el0())
                        val |= ARMV8_PMU_PMCR_LC;
                __vcpu_sys_reg(vcpu, PMCR_EL0) = val;
                kvm_pmu_handle_pmcr(vcpu, val);
                kvm_vcpu_pmu_restore_guest(vcpu);
        } else {
                /* PMCR.P & PMCR.C are RAZ */
                val = __vcpu_sys_reg(vcpu, PMCR_EL0)
                      & ~(ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C);
                p->regval = val;
        }

        return true;
}

static bool access_pmselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        if (pmu_access_event_counter_el0_disabled(vcpu))
                return false;

        if (p->is_write)
                __vcpu_sys_reg(vcpu, PMSELR_EL0) = p->regval;
        else
                /* return PMSELR.SEL field */
                p->regval = __vcpu_sys_reg(vcpu, PMSELR_EL0)
                            & ARMV8_PMU_COUNTER_MASK;

        return true;
}

static bool access_pmceid(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        u64 pmceid, mask, shift;

        BUG_ON(p->is_write);

        if (pmu_access_el0_disabled(vcpu))
                return false;

        get_access_mask(r, &mask, &shift);

        pmceid = kvm_pmu_get_pmceid(vcpu, (p->Op2 & 1));
        pmceid &= mask;
        pmceid >>= shift;

        p->regval = pmceid;

        return true;
}

static bool pmu_counter_idx_valid(struct kvm_vcpu *vcpu, u64 idx)
{
        u64 pmcr, val;

        pmcr = __vcpu_sys_reg(vcpu, PMCR_EL0);
        val = (pmcr >> ARMV8_PMU_PMCR_N_SHIFT) & ARMV8_PMU_PMCR_N_MASK;
        if (idx >= val && idx != ARMV8_PMU_CYCLE_IDX) {
                kvm_inject_undefined(vcpu);
                return false;
        }

        return true;
}

static bool access_pmu_evcntr(struct kvm_vcpu *vcpu,
                              struct sys_reg_params *p,
                              const struct sys_reg_desc *r)
{
        u64 idx = ~0UL;

        if (r->CRn == 9 && r->CRm == 13) {
                if (r->Op2 == 2) {
                        /* PMXEVCNTR_EL0 */
                        if (pmu_access_event_counter_el0_disabled(vcpu))
                                return false;

                        idx = __vcpu_sys_reg(vcpu, PMSELR_EL0)
                              & ARMV8_PMU_COUNTER_MASK;
                } else if (r->Op2 == 0) {
                        /* PMCCNTR_EL0 */
                        if (pmu_access_cycle_counter_el0_disabled(vcpu))
                                return false;

                        idx = ARMV8_PMU_CYCLE_IDX;
                }
        } else if (r->CRn == 0 && r->CRm == 9) {
                /* PMCCNTR */
                if (pmu_access_event_counter_el0_disabled(vcpu))
                        return false;

                idx = ARMV8_PMU_CYCLE_IDX;
        } else if (r->CRn == 14 && (r->CRm & 12) == 8) {
                /* PMEVCNTRn_EL0 */
                if (pmu_access_event_counter_el0_disabled(vcpu))
                        return false;

                idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
        }

        /* Catch any decoding mistake */
        WARN_ON(idx == ~0UL);

        if (!pmu_counter_idx_valid(vcpu, idx))
                return false;

        if (p->is_write) {
                if (pmu_access_el0_disabled(vcpu))
                        return false;

                kvm_pmu_set_counter_value(vcpu, idx, p->regval);
        } else {
                p->regval = kvm_pmu_get_counter_value(vcpu, idx);
        }

        return true;
}

static bool access_pmu_evtyper(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                               const struct sys_reg_desc *r)
{
        u64 idx, reg;

        if (pmu_access_el0_disabled(vcpu))
                return false;

        if (r->CRn == 9 && r->CRm == 13 && r->Op2 == 1) {
                /* PMXEVTYPER_EL0 */
                idx = __vcpu_sys_reg(vcpu, PMSELR_EL0) & ARMV8_PMU_COUNTER_MASK;
                reg = PMEVTYPER0_EL0 + idx;
        } else if (r->CRn == 14 && (r->CRm & 12) == 12) {
                idx = ((r->CRm & 3) << 3) | (r->Op2 & 7);
                if (idx == ARMV8_PMU_CYCLE_IDX)
                        reg = PMCCFILTR_EL0;
                else
                        /* PMEVTYPERn_EL0 */
                        reg = PMEVTYPER0_EL0 + idx;
        } else {
                BUG();
        }

        if (!pmu_counter_idx_valid(vcpu, idx))
                return false;

        if (p->is_write) {
                kvm_pmu_set_counter_event_type(vcpu, p->regval, idx);
                __vcpu_sys_reg(vcpu, reg) = p->regval & ARMV8_PMU_EVTYPE_MASK;
                kvm_vcpu_pmu_restore_guest(vcpu);
        } else {
                p->regval = __vcpu_sys_reg(vcpu, reg) & ARMV8_PMU_EVTYPE_MASK;
        }

        return true;
}

static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        u64 val, mask;

        if (pmu_access_el0_disabled(vcpu))
                return false;

        mask = kvm_pmu_valid_counter_mask(vcpu);
        if (p->is_write) {
                val = p->regval & mask;
                if (r->Op2 & 0x1) {
                        /* accessing PMCNTENSET_EL0 */
                        __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) |= val;
                        kvm_pmu_enable_counter_mask(vcpu, val);
                        kvm_vcpu_pmu_restore_guest(vcpu);
                } else {
                        /* accessing PMCNTENCLR_EL0 */
                        __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) &= ~val;
                        kvm_pmu_disable_counter_mask(vcpu, val);
                }
        } else {
                p->regval = __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask;
        }

        return true;
}

static bool access_pminten(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        u64 mask = kvm_pmu_valid_counter_mask(vcpu);

        if (check_pmu_access_disabled(vcpu, 0))
                return false;

        if (p->is_write) {
                u64 val = p->regval & mask;

                if (r->Op2 & 0x1)
                        /* accessing PMINTENSET_EL1 */
                        __vcpu_sys_reg(vcpu, PMINTENSET_EL1) |= val;
                else
                        /* accessing PMINTENCLR_EL1 */
                        __vcpu_sys_reg(vcpu, PMINTENSET_EL1) &= ~val;
        } else {
                p->regval = __vcpu_sys_reg(vcpu, PMINTENSET_EL1) & mask;
        }

        return true;
}

static bool access_pmovs(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                         const struct sys_reg_desc *r)
{
        u64 mask = kvm_pmu_valid_counter_mask(vcpu);

        if (pmu_access_el0_disabled(vcpu))
                return false;

        if (p->is_write) {
                if (r->CRm & 0x2)
                        /* accessing PMOVSSET_EL0 */
                        __vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= (p->regval & mask);
                else
                        /* accessing PMOVSCLR_EL0 */
                        __vcpu_sys_reg(vcpu, PMOVSSET_EL0) &= ~(p->regval & mask);
        } else {
                p->regval = __vcpu_sys_reg(vcpu, PMOVSSET_EL0) & mask;
        }

        return true;
}

static bool access_pmswinc(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                           const struct sys_reg_desc *r)
{
        u64 mask;

        if (!p->is_write)
                return read_from_write_only(vcpu, p, r);

        if (pmu_write_swinc_el0_disabled(vcpu))
                return false;

        mask = kvm_pmu_valid_counter_mask(vcpu);
        kvm_pmu_software_increment(vcpu, p->regval & mask);
        return true;
}

static bool access_pmuserenr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                             const struct sys_reg_desc *r)
{
        if (p->is_write) {
                if (!vcpu_mode_priv(vcpu)) {
                        kvm_inject_undefined(vcpu);
                        return false;
                }

                __vcpu_sys_reg(vcpu, PMUSERENR_EL0) =
                               p->regval & ARMV8_PMU_USERENR_MASK;
        } else {
                p->regval = __vcpu_sys_reg(vcpu, PMUSERENR_EL0)
                            & ARMV8_PMU_USERENR_MASK;
        }

        return true;
}

/* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
#define DBG_BCR_BVR_WCR_WVR_EL1(n)                                      \
        { SYS_DESC(SYS_DBGBVRn_EL1(n)),                                 \
          trap_bvr, reset_bvr, 0, 0, get_bvr, set_bvr },                \
        { SYS_DESC(SYS_DBGBCRn_EL1(n)),                                 \
          trap_bcr, reset_bcr, 0, 0, get_bcr, set_bcr },                \
        { SYS_DESC(SYS_DBGWVRn_EL1(n)),                                 \
          trap_wvr, reset_wvr, 0, 0,  get_wvr, set_wvr },               \
        { SYS_DESC(SYS_DBGWCRn_EL1(n)),                                 \
          trap_wcr, reset_wcr, 0, 0,  get_wcr, set_wcr }

#define PMU_SYS_REG(r)                                          \
        SYS_DESC(r), .reset = reset_unknown, .visibility = pmu_visibility

/* Macro to expand the PMEVCNTRn_EL0 register */
#define PMU_PMEVCNTR_EL0(n)                                             \
        { PMU_SYS_REG(SYS_PMEVCNTRn_EL0(n)),                            \
          .access = access_pmu_evcntr, .reg = (PMEVCNTR0_EL0 + n), }

/* Macro to expand the PMEVTYPERn_EL0 register */
#define PMU_PMEVTYPER_EL0(n)                                            \
        { PMU_SYS_REG(SYS_PMEVTYPERn_EL0(n)),                           \
          .access = access_pmu_evtyper, .reg = (PMEVTYPER0_EL0 + n), }

static bool undef_access(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                         const struct sys_reg_desc *r)
{
        kvm_inject_undefined(vcpu);

        return false;
}

/* Macro to expand the AMU counter and type registers*/
#define AMU_AMEVCNTR0_EL0(n) { SYS_DESC(SYS_AMEVCNTR0_EL0(n)), undef_access }
#define AMU_AMEVTYPER0_EL0(n) { SYS_DESC(SYS_AMEVTYPER0_EL0(n)), undef_access }
#define AMU_AMEVCNTR1_EL0(n) { SYS_DESC(SYS_AMEVCNTR1_EL0(n)), undef_access }
#define AMU_AMEVTYPER1_EL0(n) { SYS_DESC(SYS_AMEVTYPER1_EL0(n)), undef_access }

static unsigned int ptrauth_visibility(const struct kvm_vcpu *vcpu,
                        const struct sys_reg_desc *rd)
{
        return vcpu_has_ptrauth(vcpu) ? 0 : REG_HIDDEN;
}

/*
 * If we land here on a PtrAuth access, that is because we didn't
 * fixup the access on exit by allowing the PtrAuth sysregs. The only
 * way this happens is when the guest does not have PtrAuth support
 * enabled.
 */
#define __PTRAUTH_KEY(k)                                                \
        { SYS_DESC(SYS_## k), undef_access, reset_unknown, k,           \
        .visibility = ptrauth_visibility}

#define PTRAUTH_KEY(k)                                                  \
        __PTRAUTH_KEY(k ## KEYLO_EL1),                                  \
        __PTRAUTH_KEY(k ## KEYHI_EL1)

static bool access_arch_timer(struct kvm_vcpu *vcpu,
                              struct sys_reg_params *p,
                              const struct sys_reg_desc *r)
{
        enum kvm_arch_timers tmr;
        enum kvm_arch_timer_regs treg;
        u64 reg = reg_to_encoding(r);

        switch (reg) {
        case SYS_CNTP_TVAL_EL0:
        case SYS_AARCH32_CNTP_TVAL:
                tmr = TIMER_PTIMER;
                treg = TIMER_REG_TVAL;
                break;
        case SYS_CNTP_CTL_EL0:
        case SYS_AARCH32_CNTP_CTL:
                tmr = TIMER_PTIMER;
                treg = TIMER_REG_CTL;
                break;
        case SYS_CNTP_CVAL_EL0:
        case SYS_AARCH32_CNTP_CVAL:
                tmr = TIMER_PTIMER;
                treg = TIMER_REG_CVAL;
                break;
        default:
                BUG();
        }

        if (p->is_write)
                kvm_arm_timer_write_sysreg(vcpu, tmr, treg, p->regval);
        else
                p->regval = kvm_arm_timer_read_sysreg(vcpu, tmr, treg);

        return true;
}

#define FEATURE(x)      (GENMASK_ULL(x##_SHIFT + 3, x##_SHIFT))

/* Read a sanitised cpufeature ID register by sys_reg_desc */
static u64 read_id_reg(const struct kvm_vcpu *vcpu,
                struct sys_reg_desc const *r, bool raz)
{
        u32 id = reg_to_encoding(r);
        u64 val = raz ? 0 : read_sanitised_ftr_reg(id);

        switch (id) {
        case SYS_ID_AA64PFR0_EL1:
                if (!vcpu_has_sve(vcpu))
                        val &= ~FEATURE(ID_AA64PFR0_SVE);
                val &= ~FEATURE(ID_AA64PFR0_AMU);
                val &= ~FEATURE(ID_AA64PFR0_CSV2);
                val |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV2), (u64)vcpu->kvm->arch.pfr0_csv2);
                val &= ~FEATURE(ID_AA64PFR0_CSV3);
                val |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV3), (u64)vcpu->kvm->arch.pfr0_csv3);
                break;
        case SYS_ID_AA64PFR1_EL1:
                val &= ~FEATURE(ID_AA64PFR1_MTE);
                break;
        case SYS_ID_AA64ISAR1_EL1:
                if (!vcpu_has_ptrauth(vcpu))
                        val &= ~(FEATURE(ID_AA64ISAR1_APA) |
                                 FEATURE(ID_AA64ISAR1_API) |
                                 FEATURE(ID_AA64ISAR1_GPA) |
                                 FEATURE(ID_AA64ISAR1_GPI));
                break;
        case SYS_ID_AA64DFR0_EL1:
                /* Limit debug to ARMv8.0 */
                val &= ~FEATURE(ID_AA64DFR0_DEBUGVER);
                val |= FIELD_PREP(FEATURE(ID_AA64DFR0_DEBUGVER), 6);
                /* Limit guests to PMUv3 for ARMv8.4 */
                val = cpuid_feature_cap_perfmon_field(val,
                                                      ID_AA64DFR0_PMUVER_SHIFT,
                                                      kvm_vcpu_has_pmu(vcpu) ? ID_AA64DFR0_PMUVER_8_4 : 0);
                /* Hide SPE from guests */
                val &= ~FEATURE(ID_AA64DFR0_PMSVER);
                break;
        case SYS_ID_DFR0_EL1:
                /* Limit guests to PMUv3 for ARMv8.4 */
                val = cpuid_feature_cap_perfmon_field(val,
                                                      ID_DFR0_PERFMON_SHIFT,
                                                      kvm_vcpu_has_pmu(vcpu) ? ID_DFR0_PERFMON_8_4 : 0);
                break;
        }

        return val;
}

static unsigned int id_visibility(const struct kvm_vcpu *vcpu,
                                  const struct sys_reg_desc *r)
{
        u32 id = reg_to_encoding(r);

        switch (id) {
        case SYS_ID_AA64ZFR0_EL1:
                if (!vcpu_has_sve(vcpu))
                        return REG_RAZ;
                break;
        }

        return 0;
}

/* cpufeature ID register access trap handlers */

static bool __access_id_reg(struct kvm_vcpu *vcpu,
                            struct sys_reg_params *p,
                            const struct sys_reg_desc *r,
                            bool raz)
{
        if (p->is_write)
                return write_to_read_only(vcpu, p, r);

        p->regval = read_id_reg(vcpu, r, raz);
        return true;
}

static bool access_id_reg(struct kvm_vcpu *vcpu,
                          struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        bool raz = sysreg_visible_as_raz(vcpu, r);

        return __access_id_reg(vcpu, p, r, raz);
}

static bool access_raz_id_reg(struct kvm_vcpu *vcpu,
                              struct sys_reg_params *p,
                              const struct sys_reg_desc *r)
{
        return __access_id_reg(vcpu, p, r, true);
}

static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
static u64 sys_reg_to_index(const struct sys_reg_desc *reg);

/* Visibility overrides for SVE-specific control registers */
static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
                                   const struct sys_reg_desc *rd)
{
        if (vcpu_has_sve(vcpu))
                return 0;

        return REG_HIDDEN;
}

static int set_id_aa64pfr0_el1(struct kvm_vcpu *vcpu,
                               const struct sys_reg_desc *rd,
                               const struct kvm_one_reg *reg, void __user *uaddr)
{
        const u64 id = sys_reg_to_index(rd);
        u8 csv2, csv3;
        int err;
        u64 val;

        err = reg_from_user(&val, uaddr, id);
        if (err)
                return err;

        /*
         * Allow AA64PFR0_EL1.CSV2 to be set from userspace as long as
         * it doesn't promise more than what is actually provided (the
         * guest could otherwise be covered in ectoplasmic residue).
         */
        csv2 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_CSV2_SHIFT);
        if (csv2 > 1 ||
            (csv2 && arm64_get_spectre_v2_state() != SPECTRE_UNAFFECTED))
                return -EINVAL;

        /* Same thing for CSV3 */
        csv3 = cpuid_feature_extract_unsigned_field(val, ID_AA64PFR0_CSV3_SHIFT);
        if (csv3 > 1 ||
            (csv3 && arm64_get_meltdown_state() != SPECTRE_UNAFFECTED))
                return -EINVAL;

        /* We can only differ with CSV[23], and anything else is an error */
        val ^= read_id_reg(vcpu, rd, false);
        val &= ~((0xFUL << ID_AA64PFR0_CSV2_SHIFT) |
                 (0xFUL << ID_AA64PFR0_CSV3_SHIFT));
        if (val)
                return -EINVAL;

        vcpu->kvm->arch.pfr0_csv2 = csv2;
        vcpu->kvm->arch.pfr0_csv3 = csv3 ;

        return 0;
}

/*
 * cpufeature ID register user accessors
 *
 * For now, these registers are immutable for userspace, so no values
 * are stored, and for set_id_reg() we don't allow the effective value
 * to be changed.
 */
static int __get_id_reg(const struct kvm_vcpu *vcpu,
                        const struct sys_reg_desc *rd, void __user *uaddr,
                        bool raz)
{
        const u64 id = sys_reg_to_index(rd);
        const u64 val = read_id_reg(vcpu, rd, raz);

        return reg_to_user(uaddr, &val, id);
}

static int __set_id_reg(const struct kvm_vcpu *vcpu,
                        const struct sys_reg_desc *rd, void __user *uaddr,
                        bool raz)
{
        const u64 id = sys_reg_to_index(rd);
        int err;
        u64 val;

        err = reg_from_user(&val, uaddr, id);
        if (err)
                return err;

        /* This is what we mean by invariant: you can't change it. */
        if (val != read_id_reg(vcpu, rd, raz))
                return -EINVAL;

        return 0;
}

static int get_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                      const struct kvm_one_reg *reg, void __user *uaddr)
{
        bool raz = sysreg_visible_as_raz(vcpu, rd);

        return __get_id_reg(vcpu, rd, uaddr, raz);
}

static int set_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                      const struct kvm_one_reg *reg, void __user *uaddr)
{
        bool raz = sysreg_visible_as_raz(vcpu, rd);

        return __set_id_reg(vcpu, rd, uaddr, raz);
}

static int get_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                          const struct kvm_one_reg *reg, void __user *uaddr)
{
        return __get_id_reg(vcpu, rd, uaddr, true);
}

static int set_raz_id_reg(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
                          const struct kvm_one_reg *reg, void __user *uaddr)
{
        return __set_id_reg(vcpu, rd, uaddr, true);
}

static bool access_ctr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                       const struct sys_reg_desc *r)
{
        if (p->is_write)
                return write_to_read_only(vcpu, p, r);

        p->regval = read_sanitised_ftr_reg(SYS_CTR_EL0);
        return true;
}

static bool access_clidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                         const struct sys_reg_desc *r)
{
        if (p->is_write)
                return write_to_read_only(vcpu, p, r);

        p->regval = read_sysreg(clidr_el1);
        return true;
}

static bool access_csselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        int reg = r->reg;

        if (p->is_write)
                vcpu_write_sys_reg(vcpu, p->regval, reg);
        else
                p->regval = vcpu_read_sys_reg(vcpu, reg);
        return true;
}

static bool access_ccsidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
                          const struct sys_reg_desc *r)
{
        u32 csselr;

        if (p->is_write)
                return write_to_read_only(vcpu, p, r);

        csselr = vcpu_read_sys_reg(vcpu, CSSELR_EL1);
        p->regval = get_ccsidr(csselr);

        /*
         * Guests should not be doing cache operations by set/way at all, and
         * for this reason, we trap them and attempt to infer the intent, so
         * that we can flush the entire guest's address space at the appropriate
         * time.
         * To prevent this trapping from causing performance problems, let's
         * expose the geometry of all data and unified caches (which are
         * guaranteed to be PIPT and thus non-aliasing) as 1 set and 1 way.
         * [If guests should attempt to infer aliasing properties from the
         * geometry (which is not permitted by the architecture), they would
         * only do so for virtually indexed caches.]
         */
        if (!(csselr & 1)) // data or unified cache
                p->regval &= ~GENMASK(27, 3);
        return true;
}

/* sys_reg_desc initialiser for known cpufeature ID registers */
#define ID_SANITISED(name) {                    \
        SYS_DESC(SYS_##name),                   \
        .access = access_id_reg,                \
        .get_user = get_id_reg,                 \
        .set_user = set_id_reg,                 \
        .visibility = id_visibility,            \
}

/*
 * sys_reg_desc initialiser for architecturally unallocated cpufeature ID
 * register with encoding Op0=3, Op1=0, CRn=0, CRm=crm, Op2=op2
 * (1 <= crm < 8, 0 <= Op2 < 8).
 */
#define ID_UNALLOCATED(crm, op2) {                      \
        Op0(3), Op1(0), CRn(0), CRm(crm), Op2(op2),     \
        .access = access_raz_id_reg,                    \
        .get_user = get_raz_id_reg,                     \
        .set_user = set_raz_id_reg,                     \
}

/*
 * sys_reg_desc initialiser for known ID registers that we hide from guests.
 * For now, these are exposed just like unallocated ID regs: they appear
 * RAZ for the guest.
 */
#define ID_HIDDEN(name) {                       \
        SYS_DESC(SYS_##name),                   \
        .access = access_raz_id_reg,            \
        .get_user = get_raz_id_reg,             \
        .set_user = set_raz_id_reg,             \
}

/*
 * Architected system registers.
 * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
 *
 * Debug handling: We do trap most, if not all debug related system
 * registers. The implementation is good enough to ensure that a guest
 * can use these with minimal performance degradation. The drawback is
 * that we don't implement any of the external debug, none of the
 * OSlock protocol. This should be revisited if we ever encounter a
 * more demanding guest...
 */
static const struct sys_reg_desc sys_reg_descs[] = {
        { SYS_DESC(SYS_DC_ISW), access_dcsw },
        { SYS_DESC(SYS_DC_CSW), access_dcsw },
        { SYS_DESC(SYS_DC_CISW), access_dcsw },

        DBG_BCR_BVR_WCR_WVR_EL1(0),
        DBG_BCR_BVR_WCR_WVR_EL1(1),
        { SYS_DESC(SYS_MDCCINT_EL1), trap_debug_regs, reset_val, MDCCINT_EL1, 0 },
        { SYS_DESC(SYS_MDSCR_EL1), trap_debug_regs, reset_val, MDSCR_EL1, 0 },
        DBG_BCR_BVR_WCR_WVR_EL1(2),
        DBG_BCR_BVR_WCR_WVR_EL1(3),
        DBG_BCR_BVR_WCR_WVR_EL1(4),
        DBG_BCR_BVR_WCR_WVR_EL1(5),
        DBG_BCR_BVR_WCR_WVR_EL1(6),
        DBG_BCR_BVR_WCR_WVR_EL1(7),
        DBG_BCR_BVR_WCR_WVR_EL1(8),
        DBG_BCR_BVR_WCR_WVR_EL1(9),
        DBG_BCR_BVR_WCR_WVR_EL1(10),
        DBG_BCR_BVR_WCR_WVR_EL1(11),
        DBG_BCR_BVR_WCR_WVR_EL1(12),
        DBG_BCR_BVR_WCR_WVR_EL1(13),
        DBG_BCR_BVR_WCR_WVR_EL1(14),
        DBG_BCR_BVR_WCR_WVR_EL1(15),

        { SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 },
        { SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi },
        { SYS_DESC(SYS_DBGCLAIMCLR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_DBGAUTHSTATUS_EL1), trap_dbgauthstatus_el1 },

        { SYS_DESC(SYS_MDCCSR_EL0), trap_raz_wi },
        { SYS_DESC(SYS_DBGDTR_EL0), trap_raz_wi },
        // DBGDTR[TR]X_EL0 share the same encoding
        { SYS_DESC(SYS_DBGDTRTX_EL0), trap_raz_wi },

        { SYS_DESC(SYS_DBGVCR32_EL2), NULL, reset_val, DBGVCR32_EL2, 0 },

        { SYS_DESC(SYS_MPIDR_EL1), NULL, reset_mpidr, MPIDR_EL1 },

        /*
         * ID regs: all ID_SANITISED() entries here must have corresponding
         * entries in arm64_ftr_regs[].
         */

        /* AArch64 mappings of the AArch32 ID registers */
        /* CRm=1 */
        ID_SANITISED(ID_PFR0_EL1),
        ID_SANITISED(ID_PFR1_EL1),
        ID_SANITISED(ID_DFR0_EL1),
        ID_HIDDEN(ID_AFR0_EL1),
        ID_SANITISED(ID_MMFR0_EL1),
        ID_SANITISED(ID_MMFR1_EL1),
        ID_SANITISED(ID_MMFR2_EL1),
        ID_SANITISED(ID_MMFR3_EL1),

        /* CRm=2 */
        ID_SANITISED(ID_ISAR0_EL1),
        ID_SANITISED(ID_ISAR1_EL1),
        ID_SANITISED(ID_ISAR2_EL1),
        ID_SANITISED(ID_ISAR3_EL1),
        ID_SANITISED(ID_ISAR4_EL1),
        ID_SANITISED(ID_ISAR5_EL1),
        ID_SANITISED(ID_MMFR4_EL1),
        ID_SANITISED(ID_ISAR6_EL1),

        /* CRm=3 */
        ID_SANITISED(MVFR0_EL1),
        ID_SANITISED(MVFR1_EL1),
        ID_SANITISED(MVFR2_EL1),
        ID_UNALLOCATED(3,3),
        ID_SANITISED(ID_PFR2_EL1),
        ID_HIDDEN(ID_DFR1_EL1),
        ID_SANITISED(ID_MMFR5_EL1),
        ID_UNALLOCATED(3,7),

        /* AArch64 ID registers */
        /* CRm=4 */
        { SYS_DESC(SYS_ID_AA64PFR0_EL1), .access = access_id_reg,
          .get_user = get_id_reg, .set_user = set_id_aa64pfr0_el1, },
        ID_SANITISED(ID_AA64PFR1_EL1),
        ID_UNALLOCATED(4,2),
        ID_UNALLOCATED(4,3),
        ID_SANITISED(ID_AA64ZFR0_EL1),
        ID_UNALLOCATED(4,5),
        ID_UNALLOCATED(4,6),
        ID_UNALLOCATED(4,7),

        /* CRm=5 */
        ID_SANITISED(ID_AA64DFR0_EL1),
        ID_SANITISED(ID_AA64DFR1_EL1),
        ID_UNALLOCATED(5,2),
        ID_UNALLOCATED(5,3),
        ID_HIDDEN(ID_AA64AFR0_EL1),
        ID_HIDDEN(ID_AA64AFR1_EL1),
        ID_UNALLOCATED(5,6),
        ID_UNALLOCATED(5,7),

        /* CRm=6 */
        ID_SANITISED(ID_AA64ISAR0_EL1),
        ID_SANITISED(ID_AA64ISAR1_EL1),
        ID_UNALLOCATED(6,2),
        ID_UNALLOCATED(6,3),
        ID_UNALLOCATED(6,4),
        ID_UNALLOCATED(6,5),
        ID_UNALLOCATED(6,6),
        ID_UNALLOCATED(6,7),

        /* CRm=7 */
        ID_SANITISED(ID_AA64MMFR0_EL1),
        ID_SANITISED(ID_AA64MMFR1_EL1),
        ID_SANITISED(ID_AA64MMFR2_EL1),
        ID_UNALLOCATED(7,3),
        ID_UNALLOCATED(7,4),
        ID_UNALLOCATED(7,5),
        ID_UNALLOCATED(7,6),
        ID_UNALLOCATED(7,7),

        { SYS_DESC(SYS_SCTLR_EL1), access_vm_reg, reset_val, SCTLR_EL1, 0x00C50078 },
        { SYS_DESC(SYS_ACTLR_EL1), access_actlr, reset_actlr, ACTLR_EL1 },
        { SYS_DESC(SYS_CPACR_EL1), NULL, reset_val, CPACR_EL1, 0 },

        { SYS_DESC(SYS_RGSR_EL1), undef_access },
        { SYS_DESC(SYS_GCR_EL1), undef_access },

        { SYS_DESC(SYS_ZCR_EL1), NULL, reset_val, ZCR_EL1, 0, .visibility = sve_visibility },
        { SYS_DESC(SYS_TRFCR_EL1), undef_access },
        { SYS_DESC(SYS_TTBR0_EL1), access_vm_reg, reset_unknown, TTBR0_EL1 },
        { SYS_DESC(SYS_TTBR1_EL1), access_vm_reg, reset_unknown, TTBR1_EL1 },
        { SYS_DESC(SYS_TCR_EL1), access_vm_reg, reset_val, TCR_EL1, 0 },

        PTRAUTH_KEY(APIA),
        PTRAUTH_KEY(APIB),
        PTRAUTH_KEY(APDA),
        PTRAUTH_KEY(APDB),
        PTRAUTH_KEY(APGA),

        { SYS_DESC(SYS_AFSR0_EL1), access_vm_reg, reset_unknown, AFSR0_EL1 },
        { SYS_DESC(SYS_AFSR1_EL1), access_vm_reg, reset_unknown, AFSR1_EL1 },
        { SYS_DESC(SYS_ESR_EL1), access_vm_reg, reset_unknown, ESR_EL1 },

        { SYS_DESC(SYS_ERRIDR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERRSELR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXFR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXCTLR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXSTATUS_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXADDR_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXMISC0_EL1), trap_raz_wi },
        { SYS_DESC(SYS_ERXMISC1_EL1), trap_raz_wi },

        { SYS_DESC(SYS_TFSR_EL1), undef_access },
        { SYS_DESC(SYS_TFSRE0_EL1), undef_access },

        { SYS_DESC(SYS_FAR_EL1), access_vm_reg, reset_unknown, FAR_EL1 },
        { SYS_DESC(SYS_PAR_EL1), NULL, reset_unknown, PAR_EL1 },

        { SYS_DESC(SYS_PMSCR_EL1), undef_access },
        { SYS_DESC(SYS_PMSNEVFR_EL1), undef_access },
        { SYS_DESC(SYS_PMSICR_EL1), undef_access },
        { SYS_DESC(SYS_PMSIRR_EL1), undef_access },
        { SYS_DESC(SYS_PMSFCR_EL1), undef_access },
        { SYS_DESC(SYS_PMSEVFR_EL1), undef_access },
        { SYS_DESC(SYS_PMSLATFR_EL1), undef_access },
        { SYS_DESC(SYS_PMSIDR_EL1), undef_access },
        { SYS_DESC(SYS_PMBLIMITR_EL1), undef_access },
        { SYS_DESC(SYS_PMBPTR_EL1), undef_access },
        { SYS_DESC(SYS_PMBSR_EL1), undef_access },
        /* PMBIDR_EL1 is not trapped */

        { PMU_SYS_REG(SYS_PMINTENSET_EL1),
          .access = access_pminten, .reg = PMINTENSET_EL1 },
        { PMU_SYS_REG(SYS_PMINTENCLR_EL1),
          .access = access_pminten, .reg = PMINTENSET_EL1 },
        { SYS_DESC(SYS_PMMIR_EL1), trap_raz_wi },

        { SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
        { SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },

        { SYS_DESC(SYS_LORSA_EL1), trap_loregion },
        { SYS_DESC(SYS_LOREA_EL1), trap_loregion },
        { SYS_DESC(SYS_LORN_EL1), trap_loregion },
        { SYS_DESC(SYS_LORC_EL1), trap_loregion },
        { SYS_DESC(SYS_LORID_EL1), trap_loregion },

        { SYS_DESC(SYS_VBAR_EL1), NULL, reset_val, VBAR_EL1, 0 },
        { SYS_DESC(SYS_DISR_EL1), NULL, reset_val, DISR_EL1, 0 },

        { SYS_DESC(SYS_ICC_IAR0_EL1), write_to_read_only },
        { SYS_DESC(SYS_ICC_EOIR0_EL1), read_from_write_only },
        { SYS_DESC(SYS_ICC_HPPIR0_EL1), write_to_read_only },
        { SYS_DESC(SYS_ICC_DIR_EL1), read_from_write_only },
        { SYS_DESC(SYS_ICC_RPR_EL1), write_to_read_only },
        { SYS_DESC(SYS_ICC_SGI1R_EL1), access_gic_sgi },
        { SYS_DESC(SYS_ICC_ASGI1R_EL1), access_gic_sgi },
        { SYS_DESC(SYS_ICC_SGI0R_EL1), access_gic_sgi },
        { SYS_DESC(SYS_ICC_IAR1_EL1), write_to_read_only },
        { SYS_DESC(SYS_ICC_EOIR1_EL1), read_from_write_only },
        { SYS_DESC(SYS_ICC_HPPIR1_EL1), write_to_read_only },
        { SYS_DESC(SYS_ICC_SRE_EL1), access_gic_sre },

        { SYS_DESC(SYS_CONTEXTIDR_EL1), access_vm_reg, reset_val, CONTEXTIDR_EL1, 0 },
        { SYS_DESC(SYS_TPIDR_EL1), NULL, reset_unknown, TPIDR_EL1 },

        { SYS_DESC(SYS_SCXTNUM_EL1), undef_access },

        { SYS_DESC(SYS_CNTKCTL_EL1), NULL, reset_val, CNTKCTL_EL1, 0},

        { SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr },
        { SYS_DESC(SYS_CLIDR_EL1), access_clidr },
        { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 },
        { SYS_DESC(SYS_CTR_EL0), access_ctr },

        { PMU_SYS_REG(SYS_PMCR_EL0), .access = access_pmcr,
          .reset = reset_pmcr, .reg = PMCR_EL0 },
        { PMU_SYS_REG(SYS_PMCNTENSET_EL0),
          .access = access_pmcnten, .reg = PMCNTENSET_EL0 },
        { PMU_SYS_REG(SYS_PMCNTENCLR_EL0),
          .access = access_pmcnten, .reg = PMCNTENSET_EL0 },
        { PMU_SYS_REG(SYS_PMOVSCLR_EL0),
          .access = access_pmovs, .reg = PMOVSSET_EL0 },
        { PMU_SYS_REG(SYS_PMSWINC_EL0),
          .access = access_pmswinc, .reg = PMSWINC_EL0 },
        { PMU_SYS_REG(SYS_PMSELR_EL0),
          .access = access_pmselr, .reg = PMSELR_EL0 },
        { PMU_SYS_REG(SYS_PMCEID0_EL0),
          .access = access_pmceid, .reset = NULL },
        { PMU_SYS_REG(SYS_PMCEID1_EL0),
          .access = access_pmceid, .reset = NULL },
        { PMU_SYS_REG(SYS_PMCCNTR_EL0),
          .access = access_pmu_evcntr, .reg = PMCCNTR_EL0 },
        { PMU_SYS_REG(SYS_PMXEVTYPER_EL0),
          .access = access_pmu_evtyper, .reset = NULL },
        { PMU_SYS_REG(SYS_PMXEVCNTR_EL0),
          .access = access_pmu_evcntr, .reset = NULL },
        /*
         * PMUSERENR_EL0 resets as unknown in 64bit mode while it resets as zero
         * in 32bit mode. Here we choose to reset it as zero for consistency.
         */
        { PMU_SYS_REG(SYS_PMUSERENR_EL0), .access = access_pmuserenr,
          .reset = reset_val, .reg = PMUSERENR_EL0, .val = 0 },
        { PMU_SYS_REG(SYS_PMOVSSET_EL0),
          .access = access_pmovs, .reg = PMOVSSET_EL0 },

        { SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
        { SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },

        { SYS_DESC(SYS_SCXTNUM_EL0), undef_access },

        { SYS_DESC(SYS_AMCR_EL0), undef_access },
        { SYS_DESC(SYS_AMCFGR_EL0), undef_access },
        { SYS_DESC(SYS_AMCGCR_EL0), undef_access },
        { SYS_DESC(SYS_AMUSERENR_EL0), undef_access },
        { SYS_DESC(SYS_AMCNTENCLR0_EL0), undef_access },
        { SYS_DESC(SYS_AMCNTENSET0_EL0), undef_access },
        { SYS_DESC(SYS_AMCNTENCLR1_EL0), undef_access },
        { SYS_DESC(SYS_AMCNTENSET1_EL0), undef_access },
        AMU_AMEVCNTR0_EL0(0),
        AMU_AMEVCNTR0_EL0(1),
        AMU_AMEVCNTR0_EL0(2),
        AMU_AMEVCNTR0_EL0(3),
        AMU_AMEVCNTR0_EL0(4),
        AMU_AMEVCNTR0_EL0(5),
        AMU_AMEVCNTR0_EL0(6),
        AMU_AMEVCNTR0_EL0(7),
        AMU_AMEVCNTR0_EL0(8),
        AMU_AMEVCNTR0_EL0(9),
        AMU_AMEVCNTR0_EL0(10),
        AMU_AMEVCNTR0_EL0(11),
        AMU_AMEVCNTR0_EL0(12),
        AMU_AMEVCNTR0_EL0(13),
        AMU_AMEVCNTR0_EL0(14),
        AMU_AMEVCNTR0_EL0(15),
        AMU_AMEVTYPER0_EL0(0),
        AMU_AMEVTYPER0_EL0(1),
        AMU_AMEVTYPER0_EL0(2),
        AMU_AMEVTYPER0_EL0(3),
        AMU_AMEVTYPER0_EL0(4),
        AMU_AMEVTYPER0_EL0(5),
        AMU_AMEVTYPER0_EL0(6),
        AMU_AMEVTYPER0_EL0(7),
        AMU_AMEVTYPER0_EL0(8),
        AMU_AMEVTYPER0_EL0(9),
        AMU_AMEVTYPER0_EL0(10),
        AMU_AMEVTYPER0_EL0(11),
        AMU_AMEVTYPER0_EL0(12),
        AMU_AMEVTYPER0_EL0(13),
        AMU_AMEVTYPER0_EL0(14),
        AMU_AMEVTYPER0_EL0(15),
        AMU_AMEVCNTR1_EL0(0),
        AMU_AMEVCNTR1_EL0(1),
        AMU_AMEVCNTR1_EL0(2),
        AMU_AMEVCNTR1_EL0(3),
        AMU_AMEVCNTR1_EL0(4),
        AMU_AMEVCNTR1_EL0(5),
        AMU_AMEVCNTR1_EL0(6),
        AMU_AMEVCNTR1_EL0(7),
        AMU_AMEVCNTR1_EL0(8),
        AMU_AMEVCNTR1_EL0(9),
        AMU_AMEVCNTR1_EL0(10),
        AMU_AMEVCNTR1_EL0(11),
        AMU_AMEVCNTR1_EL0(12),
        AMU_AMEVCNTR1_EL0(13),
        AMU_AMEVCNTR1_EL0(14),
        AMU_AMEVCNTR1_EL0(15),
        AMU_AMEVTYPER1_EL0(0),
        AMU_AMEVTYPER1_EL0(1),
        AMU_AMEVTYPER1_EL0(2),
        AMU_AMEVTYPER1_EL0(3),
        AMU_AMEVTYPER1_EL0(4),
        AMU_AMEVTYPER1_EL0(5),
        AMU_AMEVTYPER1_EL0(6),
        AMU_AMEVTYPER1_EL0(7),
        AMU_AMEVTYPER1_EL0(8),
        AMU_AMEVTYPER1_EL0(9),
        AMU_AMEVTYPER1_EL0(10),
        AMU_AMEVTYPER1_EL0(11),
        AMU_AMEVTYPER1_EL0(12),
        AMU_AMEVTYPER1_EL0(13),
        AMU_AMEVTYPER1_EL0(14),
        AMU_AMEVTYPER1_EL0(15),

        { SYS_DESC(SYS_CNTP_TVAL_EL0), access_arch_timer },
        { SYS_DESC(SYS_CNTP_CTL_EL0), access_arch_timer },
        { SYS_DESC(SYS_CNTP_CVAL_EL0), access_arch_timer },

        /* PMEVCNTRn_EL0 */
        PMU_PMEVCNTR_EL0(0),
        PMU_PMEVCNTR_EL0(1),
        PMU_PMEVCNTR_EL0(2),
        PMU_PMEVCNTR_EL0(3),
        PMU_PMEVCNTR_EL0(4),
        PMU_PMEVCNTR_EL0(5),
        PMU_PMEVCNTR_EL0(6),
        PMU_PMEVCNTR_EL0(7),
        PMU_PMEVCNTR_EL0(8),
        PMU_PMEVCNTR_EL0(9),
        PMU_PMEVCNTR_EL0(10),
        PMU_PMEVCNTR_EL0(11),
        PMU_PMEVCNTR_EL0(12),
        PMU_PMEVCNTR_EL0(13),
        PMU_PMEVCNTR_EL0(14),
        PMU_PMEVCNTR_EL0(15),
        PMU_PMEVCNTR_EL0(16),
        PMU_PMEVCNTR_EL0(17),
        PMU_PMEVCNTR_EL0(18),
        PMU_PMEVCNTR_EL0(19),
        PMU_PMEVCNTR_EL0(20),
        PMU_PMEVCNTR_EL0(21),
        PMU_PMEVCNTR_EL0(22),
        PMU_PMEVCNTR_EL0(23),
        PMU_PMEVCNTR_EL0(24),
        PMU_PMEVCNTR_EL0(25),
        PMU_PMEVCNTR_EL0(26),
        PMU_PMEVCNTR_EL0(27),
        PMU_PMEVCNTR_EL0(28),
        PMU_PMEVCNTR_EL0(29),
        PMU_PMEVCNTR_EL0(30),
        /* PMEVTYPERn_EL0 */
        PMU_PMEVTYPER_EL0(0),
        PMU_PMEVTYPER_EL0(1),
        PMU_PMEVTYPER_EL0(2),
        PMU_PMEVTYPER_EL0(3),
        PMU_PMEVTYPER_EL0(4),
        PMU_PMEVTYPER_EL0(5),
        PMU_PMEVTYPER_EL0(6),
        PMU_PMEVTYPER_EL0(7),
        PMU_PMEVTYPER_EL0(8),
        PMU_PMEVTYPER_EL0(9),
        PMU_PMEVTYPER_EL0(10),
        PMU_PMEVTYPER_EL0(11),
        PMU_PMEVTYPER_EL0(12),
        PMU_PMEVTYPER_EL0(13),
        PMU_PMEVTYPER_EL0(14),
        PMU_PMEVTYPER_EL0(15),
        PMU_PMEVTYPER_EL0(16),
        PMU_PMEVTYPER_EL0(17),
        PMU_PMEVTYPER_EL0(18),
        PMU_PMEVTYPER_EL0(19),
        PMU_PMEVTYPER_EL0(20),
        PMU_PMEVTYPER_EL0(21),
        PMU_PMEVTYPER_EL0(22),
        PMU_PMEVTYPER_EL0(23),
        PMU_PMEVTYPER_EL0(24),
        PMU_PMEVTYPER_EL0(25),
        PMU_PMEVTYPER_EL0(26),
        PMU_PMEVTYPER_EL0(27),
        PMU_PMEVTYPER_EL0(28),
        PMU_PMEVTYPER_EL0(29),
        PMU_PMEVTYPER_EL0(30),
        /*
         * PMCCFILTR_EL0 resets as unknown in 64bit mode while it resets as zero
         * in 32bit mode. Here we choose to reset it as zero for consistency.
         */
        { PMU_SYS_REG(SYS_PMCCFILTR_EL0), .access = access_pmu_evtyper,
          .reset = reset_val, .reg = PMCCFILTR_EL0, .val = 0 },

        { SYS_DESC(SYS_DACR32_EL2), NULL, reset_unknown, DACR32_EL2 },
        { SYS_DESC(SYS_IFSR32_EL2), NULL, reset_unknown, IFSR32_EL2 },
        { SYS_DESC(SYS_FPEXC32_EL2), NULL, reset_val, FPEXC32_EL2, 0x700 },
};

static bool trap_dbgdidr(struct kvm_vcpu *vcpu,
                        struct sys_reg_params *p,
                        const struct sys_reg_desc *r)
{
        if (p->is_write) {
                return ignore_write(vcpu, p);
        } else {
                u64 dfr = read_sanitised_ftr_reg(SYS_ID_AA64DFR0_EL1);
                u64 pfr = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
                u32 el3 = !!cpuid_feature_extract_unsigned_field(pfr, ID_AA64PFR0_EL3_SHIFT);

                p->regval = ((((dfr >> ID_AA64DFR0_WRPS_SHIFT) & 0xf) << 28) |
                             (((dfr >> ID_AA64DFR0_BRPS_SHIFT) & 0xf) << 24) |
                             (((dfr >> ID_AA64DFR0_CTX_CMPS_SHIFT) & 0xf) << 20)
                             | (6 << 16) | (1 << 15) | (el3 << 14) | (el3 << 12));
                return true;
        }
}

/*
 * AArch32 debug register mappings
 *
 * AArch32 DBGBVRn is mapped to DBGBVRn_EL1[31:0]
 * AArch32 DBGBXVRn is mapped to DBGBVRn_EL1[63:32]
 *
 * None of the other registers share their location, so treat them as
 * if they were 64bit.
 */
#define DBG_BCR_BVR_WCR_WVR(n)                                                \
        /* DBGBVRn */                                                         \
        { AA32(LO), Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_bvr, NULL, n }, \
        /* DBGBCRn */                                                         \
        { Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_bcr, NULL, n },           \
        /* DBGWVRn */                                                         \
        { Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_wvr, NULL, n },           \
        /* DBGWCRn */                                                         \
        { Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_wcr, NULL, n }

#define DBGBXVR(n)                                                            \
        { AA32(HI), Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_bvr, NULL, n }

/*
 * Trapped cp14 registers. We generally ignore most of the external
 * debug, on the principle that they don't really make sense to a
 * guest. Revisit this one day, would this principle change.
 */
static const struct sys_reg_desc cp14_regs[] = {
        /* DBGDIDR */
        { Op1( 0), CRn( 0), CRm( 0), Op2( 0), trap_dbgdidr },
        /* DBGDTRRXext */
        { Op1( 0), CRn( 0), CRm( 0), Op2( 2), trap_raz_wi },

        DBG_BCR_BVR_WCR_WVR(0),
        /* DBGDSCRint */
        { Op1( 0), CRn( 0), CRm( 1), Op2( 0), trap_raz_wi },
        DBG_BCR_BVR_WCR_WVR(1),
        /* DBGDCCINT */
        { Op1( 0), CRn( 0), CRm( 2), Op2( 0), trap_debug_regs, NULL, MDCCINT_EL1 },
        /* DBGDSCRext */
        { Op1( 0), CRn( 0), CRm( 2), Op2( 2), trap_debug_regs, NULL, MDSCR_EL1 },
        DBG_BCR_BVR_WCR_WVR(2),
        /* DBGDTR[RT]Xint */
        { Op1( 0), CRn( 0), CRm( 3), Op2( 0), trap_raz_wi },
        /* DBGDTR[RT]Xext */
        { Op1( 0), CRn( 0), CRm( 3), Op2( 2), trap_raz_wi },
        DBG_BCR_BVR_WCR_WVR(3),
        DBG_BCR_BVR_WCR_WVR(4),
        DBG_BCR_BVR_WCR_WVR(5),
        /* DBGWFAR */
        { Op1( 0), CRn( 0), CRm( 6), Op2( 0), trap_raz_wi },
        /* DBGOSECCR */
        { Op1( 0), CRn( 0), CRm( 6), Op2( 2), trap_raz_wi },
        DBG_BCR_BVR_WCR_WVR(6),
        /* DBGVCR */
        { Op1( 0), CRn( 0), CRm( 7), Op2( 0), trap_debug_regs, NULL, DBGVCR32_EL2 },
        DBG_BCR_BVR_WCR_WVR(7),
        DBG_BCR_BVR_WCR_WVR(8),
        DBG_BCR_BVR_WCR_WVR(9),
        DBG_BCR_BVR_WCR_WVR(10),
        DBG_BCR_BVR_WCR_WVR(11),
        DBG_BCR_BVR_WCR_WVR(12),
        DBG_BCR_BVR_WCR_WVR(13),
        DBG_BCR_BVR_WCR_WVR(14),
        DBG_BCR_BVR_WCR_WVR(15),

        /* DBGDRAR (32bit) */
        { Op1( 0), CRn( 1), CRm( 0), Op2( 0), trap_raz_wi },

        DBGBXVR(0),
        /* DBGOSLAR */
        { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
        DBGBXVR(1),
        /* DBGOSLSR */
        { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
        DBGBXVR(2),
        DBGBXVR(3),
        /* DBGOSDLR */
        { Op1( 0), CRn( 1), CRm( 3), Op2( 4), trap_raz_wi },
        DBGBXVR(4),
        /* DBGPRCR */
        { Op1( 0), CRn( 1), CRm( 4), Op2( 4), trap_raz_wi },
        DBGBXVR(5),
        DBGBXVR(6),
        DBGBXVR(7),
        DBGBXVR(8),
        DBGBXVR(9),
        DBGBXVR(10),
        DBGBXVR(11),
        DBGBXVR(12),
        DBGBXVR(13),
        DBGBXVR(14),
        DBGBXVR(15),

        /* DBGDSAR (32bit) */
        { Op1( 0), CRn( 2), CRm( 0), Op2( 0), trap_raz_wi },

        /* DBGDEVID2 */
        { Op1( 0), CRn( 7), CRm( 0), Op2( 7), trap_raz_wi },
        /* DBGDEVID1 */
        { Op1( 0), CRn( 7), CRm( 1), Op2( 7), trap_raz_wi },
        /* DBGDEVID */
        { Op1( 0), CRn( 7), CRm( 2), Op2( 7), trap_raz_wi },
        /* DBGCLAIMSET */
        { Op1( 0), CRn( 7), CRm( 8), Op2( 6), trap_raz_wi },
        /* DBGCLAIMCLR */
        { Op1( 0), CRn( 7), CRm( 9), Op2( 6), trap_raz_wi },
        /* DBGAUTHSTATUS */
        { Op1( 0), CRn( 7), CRm(14), Op2( 6), trap_dbgauthstatus_el1 },
};

/* Trapped cp14 64bit registers */
static const struct sys_reg_desc cp14_64_regs[] = {
        /* DBGDRAR (64bit) */
        { Op1( 0), CRm( 1), .access = trap_raz_wi },

        /* DBGDSAR (64bit) */
        { Op1( 0), CRm( 2), .access = trap_raz_wi },
};

/* Macro to expand the PMEVCNTRn register */
#define PMU_PMEVCNTR(n)                                                 \
        /* PMEVCNTRn */                                                 \
        { Op1(0), CRn(0b1110),                                          \
          CRm((0b1000 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)),         \
          access_pmu_evcntr }

/* Macro to expand the PMEVTYPERn register */
#define PMU_PMEVTYPER(n)                                                \
        /* PMEVTYPERn */                                                \
        { Op1(0), CRn(0b1110),                                          \
          CRm((0b1100 | (((n) >> 3) & 0x3))), Op2(((n) & 0x7)),         \
          access_pmu_evtyper }

/*
 * Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,
 * depending on the way they are accessed (as a 32bit or a 64bit
 * register).
 */
static const struct sys_reg_desc cp15_regs[] = {
        { Op1( 0), CRn( 0), CRm( 0), Op2( 1), access_ctr },
        { Op1( 0), CRn( 1), CRm( 0), Op2( 0), access_vm_reg, NULL, SCTLR_EL1 },
        /* ACTLR */
        { AA32(LO), Op1( 0), CRn( 1), CRm( 0), Op2( 1), access_actlr, NULL, ACTLR_EL1 },
        /* ACTLR2 */
        { AA32(HI), Op1( 0), CRn( 1), CRm( 0), Op2( 3), access_actlr, NULL, ACTLR_EL1 },
        { Op1( 0), CRn( 2), CRm( 0), Op2( 0), access_vm_reg, NULL, TTBR0_EL1 },
        { Op1( 0), CRn( 2), CRm( 0), Op2( 1), access_vm_reg, NULL, TTBR1_EL1 },
        /* TTBCR */
        { AA32(LO), Op1( 0), CRn( 2), CRm( 0), Op2( 2), access_vm_reg, NULL, TCR_EL1 },
        /* TTBCR2 */
        { AA32(HI), Op1( 0), CRn( 2), CRm( 0), Op2( 3), access_vm_reg, NULL, TCR_EL1 },
        { Op1( 0), CRn( 3), CRm( 0), Op2( 0), access_vm_reg, NULL, DACR32_EL2 },
        /* DFSR */
        { Op1( 0), CRn( 5), CRm( 0), Op2( 0), access_vm_reg, NULL, ESR_EL1 },
        { Op1( 0), CRn( 5), CRm( 0), Op2( 1), access_vm_reg, NULL, IFSR32_EL2 },
        /* ADFSR */
        { Op1( 0), CRn( 5), CRm( 1), Op2( 0), access_vm_reg, NULL, AFSR0_EL1 },
        /* AIFSR */
        { Op1( 0), CRn( 5), CRm( 1), Op2( 1), access_vm_reg, NULL, AFSR1_EL1 },
        /* DFAR */
        { AA32(LO), Op1( 0), CRn( 6), CRm( 0), Op2( 0), access_vm_reg, NULL, FAR_EL1 },
        /* IFAR */
        { AA32(HI), Op1( 0), CRn( 6), CRm( 0), Op2( 2), access_vm_reg, NULL, FAR_EL1 },

        /*
         * DC{C,I,CI}SW operations:
         */
        { Op1( 0), CRn( 7), CRm( 6), Op2( 2), access_dcsw },
        { Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw },
        { Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },

        /* PMU */
        { Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr },
        { Op1( 0), CRn( 9), CRm(12), Op2( 1), access_pmcnten },
        { Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmcnten },
        { Op1( 0), CRn( 9), CRm(12), Op2( 3), access_pmovs },
        { Op1( 0), CRn( 9), CRm(12), Op2( 4), access_pmswinc },
        { Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr },
        { AA32(LO), Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
        { AA32(LO), Op1( 0), CRn( 9), CRm(12), Op2( 7), access_pmceid },
        { Op1( 0), CRn( 9), CRm(13), Op2( 0), access_pmu_evcntr },
        { Op1( 0), CRn( 9), CRm(13), Op2( 1), access_pmu_evtyper },
        { Op1( 0), CRn( 9), CRm(13), Op2( 2), access_pmu_evcntr },
        { Op1( 0), CRn( 9), CRm(14), Op2( 0), access_pmuserenr },
        { Op1( 0), CRn( 9), CRm(14), Op2( 1), access_pminten },
        { Op1( 0), CRn( 9), CRm(14), Op2( 2), access_pminten },
        { Op1( 0), CRn( 9), CRm(14), Op2( 3), access_pmovs },
        { AA32(HI), Op1( 0), CRn( 9), CRm(14), Op2( 4), access_pmceid },
        { AA32(HI), Op1( 0), CRn( 9), CRm(14), Op2( 5), access_pmceid },
        /* PMMIR */
        { Op1( 0), CRn( 9), CRm(14), Op2( 6), trap_raz_wi },

        /* PRRR/MAIR0 */
        { AA32(LO), Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, MAIR_EL1 },
        /* NMRR/MAIR1 */
        { AA32(HI), Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, MAIR_EL1 },
        /* AMAIR0 */
        { AA32(LO), Op1( 0), CRn(10), CRm( 3), Op2( 0), access_vm_reg, NULL, AMAIR_EL1 },
        /* AMAIR1 */
        { AA32(HI), Op1( 0), CRn(10), CRm( 3), Op2( 1), access_vm_reg, NULL, AMAIR_EL1 },

        /* ICC_SRE */
        { Op1( 0), CRn(12), CRm(12), Op2( 5), access_gic_sre },

        { Op1( 0), CRn(13), CRm( 0), Op2( 1), access_vm_reg, NULL, CONTEXTIDR_EL1 },

        /* Arch Tmers */
        { SYS_DESC(SYS_AARCH32_CNTP_TVAL), access_arch_timer },
        { SYS_DESC(SYS_AARCH32_CNTP_CTL), access_arch_timer },

        /* PMEVCNTRn */
        PMU_PMEVCNTR(0),
        PMU_PMEVCNTR(1),
        PMU_PMEVCNTR(2),
        PMU_PMEVCNTR(3),
        PMU_PMEVCNTR(4),
        PMU_PMEVCNTR(5),
        PMU_PMEVCNTR(6),
        PMU_PMEVCNTR(7),
        PMU_PMEVCNTR(8),
        PMU_PMEVCNTR(9),
        PMU_PMEVCNTR(10),
        PMU_PMEVCNTR(11),
        PMU_PMEVCNTR(12),
        PMU_PMEVCNTR(13),
        PMU_PMEVCNTR(14),
        PMU_PMEVCNTR(15),
        PMU_PMEVCNTR(16),
        PMU_PMEVCNTR(17),

        PMU_PMEVCNTR(18),
        PMU_PMEVCNTR(19),
        PMU_PMEVCNTR(20),
        PMU_PMEVCNTR(21),
        PMU_PMEVCNTR(22),
        PMU_PMEVCNTR(23),
        PMU_PMEVCNTR(24),
        PMU_PMEVCNTR(25),
        PMU_PMEVCNTR(26),
        PMU_PMEVCNTR(27),
        PMU_PMEVCNTR(28),
        PMU_PMEVCNTR(29),
        PMU_PMEVCNTR(30),
        /* PMEVTYPERn */
        PMU_PMEVTYPER(0),
        PMU_PMEVTYPER(1),
        PMU_PMEVTYPER(2),
        PMU_PMEVTYPER(3),
        PMU_PMEVTYPER(4),
        PMU_PMEVTYPER(5),
        PMU_PMEVTYPER(6),
        PMU_PMEVTYPER(7),
        PMU_PMEVTYPER(8),
        PMU_PMEVTYPER(9),
        PMU_PMEVTYPER(10),
        PMU_PMEVTYPER(11),
        PMU_PMEVTYPER(12),
        PMU_PMEVTYPER(13),
        PMU_PMEVTYPER(14),
        PMU_PMEVTYPER(15),
        PMU_PMEVTYPER(16),
        PMU_PMEVTYPER(17),
        PMU_PMEVTYPER(18),
        PMU_PMEVTYPER(19),
        PMU_PMEVTYPER(20),
        PMU_PMEVTYPER(21),
        PMU_PMEVTYPER(22),
        PMU_PMEVTYPER(23),
        PMU_PMEVTYPER(24),
        PMU_PMEVTYPER(25),
        PMU_PMEVTYPER(26),
        PMU_PMEVTYPER(27),
        PMU_PMEVTYPER(28),
        PMU_PMEVTYPER(29),
        PMU_PMEVTYPER(30),
        /* PMCCFILTR */
        { Op1(0), CRn(14), CRm(15), Op2(7), access_pmu_evtyper },

        { Op1(1), CRn( 0), CRm( 0), Op2(0), access_ccsidr },
        { Op1(1), CRn( 0), CRm( 0), Op2(1), access_clidr },
        { Op1(2), CRn( 0), CRm( 0), Op2(0), access_csselr, NULL, CSSELR_EL1 },
};

static const struct sys_reg_desc cp15_64_regs[] = {
        { Op1( 0), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, TTBR0_EL1 },
        { Op1( 0), CRn( 0), CRm( 9), Op2( 0), access_pmu_evcntr },
        { Op1( 0), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_SGI1R */
        { Op1( 1), CRn( 0), CRm( 2), Op2( 0), access_vm_reg, NULL, TTBR1_EL1 },
        { Op1( 1), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_ASGI1R */
        { Op1( 2), CRn( 0), CRm(12), Op2( 0), access_gic_sgi }, /* ICC_SGI0R */
        { SYS_DESC(SYS_AARCH32_CNTP_CVAL),    access_arch_timer },
};

static int check_sysreg_table(const struct sys_reg_desc *table, unsigned int n,
                              bool is_32)
{
        unsigned int i;

        for (i = 0; i < n; i++) {
                if (!is_32 && table[i].reg && !table[i].reset) {
                        kvm_err("sys_reg table %p entry %d has lacks reset\n",
                                table, i);
                        return 1;
                }

                if (i && cmp_sys_reg(&table[i-1], &table[i]) >= 0) {
                        kvm_err("sys_reg table %p out of order (%d)\n", table, i - 1);
                        return 1;
                }
        }

        return 0;
}

static int match_sys_reg(const void *key, const void *elt)
{
        const unsigned long pval = (unsigned long)key;
        const struct sys_reg_desc *r = elt;

        return pval - reg_to_encoding(r);
}

static const struct sys_reg_desc *find_reg(const struct sys_reg_params *params,
                                         const struct sys_reg_desc table[],
                                         unsigned int num)
{
        unsigned long pval = reg_to_encoding(params);

        return bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
}

int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu)
{
        kvm_inject_undefined(vcpu);
        return 1;
}

static void perform_access(struct kvm_vcpu *vcpu,
                           struct sys_reg_params *params,
                           const struct sys_reg_desc *r)
{
        trace_kvm_sys_access(*vcpu_pc(vcpu), params, r);

        /* Check for regs disabled by runtime config */
        if (sysreg_hidden(vcpu, r)) {
                kvm_inject_undefined(vcpu);
                return;
        }

        /*
         * Not having an accessor means that we have configured a trap
         * that we don't know how to handle. This certainly qualifies
         * as a gross bug that should be fixed right away.
         */
        BUG_ON(!r->access);

        /* Skip instruction if instructed so */
        if (likely(r->access(vcpu, params, r)))
                kvm_incr_pc(vcpu);
}

/*
 * emulate_cp --  tries to match a sys_reg access in a handling table, and
 *                call the corresponding trap handler.
 *
 * @params: pointer to the descriptor of the access
 * @table: array of trap descriptors
 * @num: size of the trap descriptor array
 *
 * Return 0 if the access has been handled, and -1 if not.
 */
static int emulate_cp(struct kvm_vcpu *vcpu,
                      struct sys_reg_params *params,
                      const struct sys_reg_desc *table,
                      size_t num)
{
        const struct sys_reg_desc *r;

        if (!table)
                return -1;      /* Not handled */

        r = find_reg(params, table, num);

        if (r) {
                perform_access(vcpu, params, r);
                return 0;
        }

        /* Not handled */
        return -1;
}

static void unhandled_cp_access(struct kvm_vcpu *vcpu,
                                struct sys_reg_params *params)
{
        u8 esr_ec = kvm_vcpu_trap_get_class(vcpu);
        int cp = -1;

        switch (esr_ec) {
        case ESR_ELx_EC_CP15_32:
        case ESR_ELx_EC_CP15_64:
                cp = 15;
                break;
        case ESR_ELx_EC_CP14_MR:
        case ESR_ELx_EC_CP14_64:
                cp = 14;
                break;
        default:
                WARN_ON(1);
        }

        print_sys_reg_msg(params,
                          "Unsupported guest CP%d access at: %08lx [%08lx]\n",
                          cp, *vcpu_pc(vcpu), *vcpu_cpsr(vcpu));
        kvm_inject_undefined(vcpu);
}

/**
 * kvm_handle_cp_64 -- handles a mrrc/mcrr trap on a guest CP14/CP15 access
 * @vcpu: The VCPU pointer
 * @run:  The kvm_run struct
 */
static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
                            const struct sys_reg_desc *global,
                            size_t nr_global)
{
        struct sys_reg_params params;
        u32 esr = kvm_vcpu_get_esr(vcpu);
        int Rt = kvm_vcpu_sys_get_rt(vcpu);
        int Rt2 = (esr >> 10) & 0x1f;

        params.CRm = (esr >> 1) & 0xf;
        params.is_write = ((esr & 1) == 0);

        params.Op0 = 0;
        params.Op1 = (esr >> 16) & 0xf;
        params.Op2 = 0;
        params.CRn = 0;

        /*
         * Make a 64-bit value out of Rt and Rt2. As we use the same trap
         * backends between AArch32 and AArch64, we get away with it.
         */
        if (params.is_write) {
                params.regval = vcpu_get_reg(vcpu, Rt) & 0xffffffff;
                params.regval |= vcpu_get_reg(vcpu, Rt2) << 32;
        }

        /*
         * If the table contains a handler, handle the
         * potential register operation in the case of a read and return
         * with success.
         */
        if (!emulate_cp(vcpu, &params, global, nr_global)) {
                /* Split up the value between registers for the read side */
                if (!params.is_write) {
                        vcpu_set_reg(vcpu, Rt, lower_32_bits(params.regval));
                        vcpu_set_reg(vcpu, Rt2, upper_32_bits(params.regval));
                }

                return 1;
        }

        unhandled_cp_access(vcpu, &params);
        return 1;
}

/**
 * kvm_handle_cp_32 -- handles a mrc/mcr trap on a guest CP14/CP15 access
 * @vcpu: The VCPU pointer
 * @run:  The kvm_run struct
 */
static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
                            const struct sys_reg_desc *global,
                            size_t nr_global)
{
        struct sys_reg_params params;
        u32 esr = kvm_vcpu_get_esr(vcpu);
        int Rt  = kvm_vcpu_sys_get_rt(vcpu);

        params.CRm = (esr >> 1) & 0xf;
        params.regval = vcpu_get_reg(vcpu, Rt);
        params.is_write = ((esr & 1) == 0);
        params.CRn = (esr >> 10) & 0xf;
        params.Op0 = 0;
        params.Op1 = (esr >> 14) & 0x7;
        params.Op2 = (esr >> 17) & 0x7;

        if (!emulate_cp(vcpu, &params, global, nr_global)) {
                if (!params.is_write)
                        vcpu_set_reg(vcpu, Rt, params.regval);
                return 1;
        }

        unhandled_cp_access(vcpu, &params);
        return 1;
}

int kvm_handle_cp15_64(struct kvm_vcpu *vcpu)
{
        return kvm_handle_cp_64(vcpu, cp15_64_regs, ARRAY_SIZE(cp15_64_regs));
}

int kvm_handle_cp15_32(struct kvm_vcpu *vcpu)
{
        return kvm_handle_cp_32(vcpu, cp15_regs, ARRAY_SIZE(cp15_regs));
}

int kvm_handle_cp14_64(struct kvm_vcpu *vcpu)
{
        return kvm_handle_cp_64(vcpu, cp14_64_regs, ARRAY_SIZE(cp14_64_regs));
}

int kvm_handle_cp14_32(struct kvm_vcpu *vcpu)
{
        return kvm_handle_cp_32(vcpu, cp14_regs, ARRAY_SIZE(cp14_regs));
}

static bool is_imp_def_sys_reg(struct sys_reg_params *params)
{
        // See ARM DDI 0487E.a, section D12.3.2
        return params->Op0 == 3 && (params->CRn & 0b1011) == 0b1011;
}

static int emulate_sys_reg(struct kvm_vcpu *vcpu,
                           struct sys_reg_params *params)
{
        const struct sys_reg_desc *r;

        r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));

        if (likely(r)) {
                perform_access(vcpu, params, r);
        } else if (is_imp_def_sys_reg(params)) {
                kvm_inject_undefined(vcpu);
        } else {
                print_sys_reg_msg(params,
                                  "Unsupported guest sys_reg access at: %lx [%08lx]\n",
                                  *vcpu_pc(vcpu), *vcpu_cpsr(vcpu));
                kvm_inject_undefined(vcpu);
        }
        return 1;
}

/**
 * kvm_reset_sys_regs - sets system registers to reset value
 * @vcpu: The VCPU pointer
 *
 * This function finds the right table above and sets the registers on the
 * virtual CPU struct to their architecturally defined reset values.
 */
void kvm_reset_sys_regs(struct kvm_vcpu *vcpu)
{
        unsigned long i;

        for (i = 0; i < ARRAY_SIZE(sys_reg_descs); i++)
                if (sys_reg_descs[i].reset)
                        sys_reg_descs[i].reset(vcpu, &sys_reg_descs[i]);
}

/**
 * kvm_handle_sys_reg -- handles a mrs/msr trap on a guest sys_reg access
 * @vcpu: The VCPU pointer
 */
int kvm_handle_sys_reg(struct kvm_vcpu *vcpu)
{
        struct sys_reg_params params;
        unsigned long esr = kvm_vcpu_get_esr(vcpu);
        int Rt = kvm_vcpu_sys_get_rt(vcpu);
        int ret;

        trace_kvm_handle_sys_reg(esr);

        params.Op0 = (esr >> 20) & 3;
        params.Op1 = (esr >> 14) & 0x7;
        params.CRn = (esr >> 10) & 0xf;
        params.CRm = (esr >> 1) & 0xf;
        params.Op2 = (esr >> 17) & 0x7;
        params.regval = vcpu_get_reg(vcpu, Rt);
        params.is_write = !(esr & 1);

        ret = emulate_sys_reg(vcpu, &params);

        if (!params.is_write)
                vcpu_set_reg(vcpu, Rt, params.regval);
        return ret;
}

/******************************************************************************
 * Userspace API
 *****************************************************************************/

static bool index_to_params(u64 id, struct sys_reg_params *params)
{
        switch (id & KVM_REG_SIZE_MASK) {
        case KVM_REG_SIZE_U64:
                /* Any unused index bits means it's not valid. */
                if (id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK
                              | KVM_REG_ARM_COPROC_MASK
                              | KVM_REG_ARM64_SYSREG_OP0_MASK
                              | KVM_REG_ARM64_SYSREG_OP1_MASK
                              | KVM_REG_ARM64_SYSREG_CRN_MASK
                              | KVM_REG_ARM64_SYSREG_CRM_MASK
                              | KVM_REG_ARM64_SYSREG_OP2_MASK))
                        return false;
                params->Op0 = ((id & KVM_REG_ARM64_SYSREG_OP0_MASK)
                               >> KVM_REG_ARM64_SYSREG_OP0_SHIFT);
                params->Op1 = ((id & KVM_REG_ARM64_SYSREG_OP1_MASK)
                               >> KVM_REG_ARM64_SYSREG_OP1_SHIFT);
                params->CRn = ((id & KVM_REG_ARM64_SYSREG_CRN_MASK)
                               >> KVM_REG_ARM64_SYSREG_CRN_SHIFT);
                params->CRm = ((id & KVM_REG_ARM64_SYSREG_CRM_MASK)
                               >> KVM_REG_ARM64_SYSREG_CRM_SHIFT);
                params->Op2 = ((id & KVM_REG_ARM64_SYSREG_OP2_MASK)
                               >> KVM_REG_ARM64_SYSREG_OP2_SHIFT);
                return true;
        default:
                return false;
        }
}

const struct sys_reg_desc *find_reg_by_id(u64 id,
                                          struct sys_reg_params *params,
                                          const struct sys_reg_desc table[],
                                          unsigned int num)
{
        if (!index_to_params(id, params))
                return NULL;

        return find_reg(params, table, num);
}

/* Decode an index value, and find the sys_reg_desc entry. */
static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
                                                    u64 id)
{
        const struct sys_reg_desc *r;
        struct sys_reg_params params;

        /* We only do sys_reg for now. */
        if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
                return NULL;

        if (!index_to_params(id, &params))
                return NULL;

        r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));

        /* Not saved in the sys_reg array and not otherwise accessible? */
        if (r && !(r->reg || r->get_user))
                r = NULL;

        return r;
}

/*
 * These are the invariant sys_reg registers: we let the guest see the
 * host versions of these, so they're part of the guest state.
 *
 * A future CPU may provide a mechanism to present different values to
 * the guest, or a future kvm may trap them.
 */

#define FUNCTION_INVARIANT(reg)                                         \
        static void get_##reg(struct kvm_vcpu *v,                       \
                              const struct sys_reg_desc *r)             \
        {                                                               \
                ((struct sys_reg_desc *)r)->val = read_sysreg(reg);     \
        }

FUNCTION_INVARIANT(midr_el1)
FUNCTION_INVARIANT(revidr_el1)
FUNCTION_INVARIANT(clidr_el1)
FUNCTION_INVARIANT(aidr_el1)

static void get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r)
{
        ((struct sys_reg_desc *)r)->val = read_sanitised_ftr_reg(SYS_CTR_EL0);
}

/* ->val is filled in by kvm_sys_reg_table_init() */
static struct sys_reg_desc invariant_sys_regs[] = {
        { SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 },
        { SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 },
        { SYS_DESC(SYS_CLIDR_EL1), NULL, get_clidr_el1 },
        { SYS_DESC(SYS_AIDR_EL1), NULL, get_aidr_el1 },
        { SYS_DESC(SYS_CTR_EL0), NULL, get_ctr_el0 },
};

static int reg_from_user(u64 *val, const void __user *uaddr, u64 id)
{
        if (copy_from_user(val, uaddr, KVM_REG_SIZE(id)) != 0)
                return -EFAULT;
        return 0;
}

static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
{
        if (copy_to_user(uaddr, val, KVM_REG_SIZE(id)) != 0)
                return -EFAULT;
        return 0;
}

static int get_invariant_sys_reg(u64 id, void __user *uaddr)
{
        struct sys_reg_params params;
        const struct sys_reg_desc *r;

        r = find_reg_by_id(id, &params, invariant_sys_regs,
                           ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;

        return reg_to_user(uaddr, &r->val, id);
}

static int set_invariant_sys_reg(u64 id, void __user *uaddr)
{
        struct sys_reg_params params;
        const struct sys_reg_desc *r;
        int err;
        u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */

        r = find_reg_by_id(id, &params, invariant_sys_regs,
                           ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;

        err = reg_from_user(&val, uaddr, id);
        if (err)
                return err;

        /* This is what we mean by invariant: you can't change it. */
        if (r->val != val)
                return -EINVAL;

        return 0;
}

static bool is_valid_cache(u32 val)
{
        u32 level, ctype;

        if (val >= CSSELR_MAX)
                return false;

        /* Bottom bit is Instruction or Data bit.  Next 3 bits are level. */
        level = (val >> 1);
        ctype = (cache_levels >> (level * 3)) & 7;

        switch (ctype) {
        case 0: /* No cache */
                return false;
        case 1: /* Instruction cache only */
                return (val & 1);
        case 2: /* Data cache only */
        case 4: /* Unified cache */
                return !(val & 1);
        case 3: /* Separate instruction and data caches */
                return true;
        default: /* Reserved: we can't know instruction or data. */
                return false;
        }
}

static int demux_c15_get(u64 id, void __user *uaddr)
{
        u32 val;
        u32 __user *uval = uaddr;

        /* Fail if we have unknown bits set. */
        if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
                   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
                return -ENOENT;

        switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
        case KVM_REG_ARM_DEMUX_ID_CCSIDR:
                if (KVM_REG_SIZE(id) != 4)
                        return -ENOENT;
                val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
                        >> KVM_REG_ARM_DEMUX_VAL_SHIFT;
                if (!is_valid_cache(val))
                        return -ENOENT;

                return put_user(get_ccsidr(val), uval);
        default:
                return -ENOENT;
        }
}

static int demux_c15_set(u64 id, void __user *uaddr)
{
        u32 val, newval;
        u32 __user *uval = uaddr;

        /* Fail if we have unknown bits set. */
        if (id & ~(KVM_REG_ARCH_MASK|KVM_REG_SIZE_MASK|KVM_REG_ARM_COPROC_MASK
                   | ((1 << KVM_REG_ARM_COPROC_SHIFT)-1)))
                return -ENOENT;

        switch (id & KVM_REG_ARM_DEMUX_ID_MASK) {
        case KVM_REG_ARM_DEMUX_ID_CCSIDR:
                if (KVM_REG_SIZE(id) != 4)
                        return -ENOENT;
                val = (id & KVM_REG_ARM_DEMUX_VAL_MASK)
                        >> KVM_REG_ARM_DEMUX_VAL_SHIFT;
                if (!is_valid_cache(val))
                        return -ENOENT;

                if (get_user(newval, uval))
                        return -EFAULT;

                /* This is also invariant: you can't change it. */
                if (newval != get_ccsidr(val))
                        return -EINVAL;
                return 0;
        default:
                return -ENOENT;
        }
}

int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
        const struct sys_reg_desc *r;
        void __user *uaddr = (void __user *)(unsigned long)reg->addr;

        if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
                return demux_c15_get(reg->id, uaddr);

        if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
                return -ENOENT;

        r = index_to_sys_reg_desc(vcpu, reg->id);
        if (!r)
                return get_invariant_sys_reg(reg->id, uaddr);

        /* Check for regs disabled by runtime config */
        if (sysreg_hidden(vcpu, r))
                return -ENOENT;

        if (r->get_user)
                return (r->get_user)(vcpu, r, reg, uaddr);

        return reg_to_user(uaddr, &__vcpu_sys_reg(vcpu, r->reg), reg->id);
}

int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
        const struct sys_reg_desc *r;
        void __user *uaddr = (void __user *)(unsigned long)reg->addr;

        if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
                return demux_c15_set(reg->id, uaddr);

        if (KVM_REG_SIZE(reg->id) != sizeof(__u64))
                return -ENOENT;

        r = index_to_sys_reg_desc(vcpu, reg->id);
        if (!r)
                return set_invariant_sys_reg(reg->id, uaddr);

        /* Check for regs disabled by runtime config */
        if (sysreg_hidden(vcpu, r))
                return -ENOENT;

        if (r->set_user)
                return (r->set_user)(vcpu, r, reg, uaddr);

        return reg_from_user(&__vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
}

static unsigned int num_demux_regs(void)
{
        unsigned int i, count = 0;

        for (i = 0; i < CSSELR_MAX; i++)
                if (is_valid_cache(i))
                        count++;

        return count;
}

static int write_demux_regids(u64 __user *uindices)
{
        u64 val = KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX;
        unsigned int i;

        val |= KVM_REG_ARM_DEMUX_ID_CCSIDR;
        for (i = 0; i < CSSELR_MAX; i++) {
                if (!is_valid_cache(i))
                        continue;
                if (put_user(val | i, uindices))
                        return -EFAULT;
                uindices++;
        }
        return 0;
}

static u64 sys_reg_to_index(const struct sys_reg_desc *reg)
{
        return (KVM_REG_ARM64 | KVM_REG_SIZE_U64 |
                KVM_REG_ARM64_SYSREG |
                (reg->Op0 << KVM_REG_ARM64_SYSREG_OP0_SHIFT) |
                (reg->Op1 << KVM_REG_ARM64_SYSREG_OP1_SHIFT) |
                (reg->CRn << KVM_REG_ARM64_SYSREG_CRN_SHIFT) |
                (reg->CRm << KVM_REG_ARM64_SYSREG_CRM_SHIFT) |
                (reg->Op2 << KVM_REG_ARM64_SYSREG_OP2_SHIFT));
}

static bool copy_reg_to_user(const struct sys_reg_desc *reg, u64 __user **uind)
{
        if (!*uind)
                return true;

        if (put_user(sys_reg_to_index(reg), *uind))
                return false;

        (*uind)++;
        return true;
}

static int walk_one_sys_reg(const struct kvm_vcpu *vcpu,
                            const struct sys_reg_desc *rd,
                            u64 __user **uind,
                            unsigned int *total)
{
        /*
         * Ignore registers we trap but don't save,
         * and for which no custom user accessor is provided.
         */
        if (!(rd->reg || rd->get_user))
                return 0;

        if (sysreg_hidden(vcpu, rd))
                return 0;

        if (!copy_reg_to_user(rd, uind))
                return -EFAULT;

        (*total)++;
        return 0;
}

/* Assumed ordered tables, see kvm_sys_reg_table_init. */
static int walk_sys_regs(struct kvm_vcpu *vcpu, u64 __user *uind)
{
        const struct sys_reg_desc *i2, *end2;
        unsigned int total = 0;
        int err;

        i2 = sys_reg_descs;
        end2 = sys_reg_descs + ARRAY_SIZE(sys_reg_descs);

        while (i2 != end2) {
                err = walk_one_sys_reg(vcpu, i2++, &uind, &total);
                if (err)
                        return err;
        }
        return total;
}

unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu)
{
        return ARRAY_SIZE(invariant_sys_regs)
                + num_demux_regs()
                + walk_sys_regs(vcpu, (u64 __user *)NULL);
}

int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
        unsigned int i;
        int err;

        /* Then give them all the invariant registers' indices. */
        for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++) {
                if (put_user(sys_reg_to_index(&invariant_sys_regs[i]), uindices))
                        return -EFAULT;
                uindices++;
        }

        err = walk_sys_regs(vcpu, uindices);
        if (err < 0)
                return err;
        uindices += err;

        return write_demux_regids(uindices);
}

void kvm_sys_reg_table_init(void)
{
        unsigned int i;
        struct sys_reg_desc clidr;

        /* Make sure tables are unique and in order. */
        BUG_ON(check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false));
        BUG_ON(check_sysreg_table(cp14_regs, ARRAY_SIZE(cp14_regs), true));
        BUG_ON(check_sysreg_table(cp14_64_regs, ARRAY_SIZE(cp14_64_regs), true));
        BUG_ON(check_sysreg_table(cp15_regs, ARRAY_SIZE(cp15_regs), true));
        BUG_ON(check_sysreg_table(cp15_64_regs, ARRAY_SIZE(cp15_64_regs), true));
        BUG_ON(check_sysreg_table(invariant_sys_regs, ARRAY_SIZE(invariant_sys_regs), false));

        /* We abuse the reset function to overwrite the table itself. */
        for (i = 0; i < ARRAY_SIZE(invariant_sys_regs); i++)
                invariant_sys_regs[i].reset(NULL, &invariant_sys_regs[i]);

        /*
         * CLIDR format is awkward, so clean it up.  See ARM B4.1.20:
         *
         *   If software reads the Cache Type fields from Ctype1
         *   upwards, once it has seen a value of 0b000, no caches
         *   exist at further-out levels of the hierarchy. So, for
         *   example, if Ctype3 is the first Cache Type field with a
         *   value of 0b000, the values of Ctype4 to Ctype7 must be
         *   ignored.
         */
        get_clidr_el1(NULL, &clidr); /* Ugly... */
        cache_levels = clidr.val;
        for (i = 0; i < 7; i++)
                if (((cache_levels >> (i*3)) & 7) == 0)
                        break;
        /* Clear all higher bits. */
        cache_levels &= (1 << (i*3))-1;
}