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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Arm Ltd.
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <asm/kvm_emulate.h>
#include <kvm/arm_hypercalls.h>
#include <kvm/arm_psci.h>
#define KVM_ARM_SMCCC_STD_FEATURES \
GENMASK(KVM_REG_ARM_STD_BMAP_BIT_COUNT - 1, 0)
#define KVM_ARM_SMCCC_STD_HYP_FEATURES \
GENMASK(KVM_REG_ARM_STD_HYP_BMAP_BIT_COUNT - 1, 0)
#define KVM_ARM_SMCCC_VENDOR_HYP_FEATURES \
GENMASK(KVM_REG_ARM_VENDOR_HYP_BMAP_BIT_COUNT - 1, 0)
static void kvm_ptp_get_time(struct kvm_vcpu *vcpu, u64 *val)
{
struct system_time_snapshot systime_snapshot;
u64 cycles = ~0UL;
u32 feature;
/*
* system time and counter value must captured at the same
* time to keep consistency and precision.
*/
ktime_get_snapshot(&systime_snapshot);
/*
* This is only valid if the current clocksource is the
* architected counter, as this is the only one the guest
* can see.
*/
if (systime_snapshot.cs_id != CSID_ARM_ARCH_COUNTER)
return;
/*
* The guest selects one of the two reference counters
* (virtual or physical) with the first argument of the SMCCC
* call. In case the identifier is not supported, error out.
*/
feature = smccc_get_arg1(vcpu);
switch (feature) {
case KVM_PTP_VIRT_COUNTER:
cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.voffset;
break;
case KVM_PTP_PHYS_COUNTER:
cycles = systime_snapshot.cycles - vcpu->kvm->arch.timer_data.poffset;
break;
default:
return;
}
/*
* This relies on the top bit of val[0] never being set for
* valid values of system time, because that is *really* far
* in the future (about 292 years from 1970, and at that stage
* nobody will give a damn about it).
*/
val[0] = upper_32_bits(systime_snapshot.real);
val[1] = lower_32_bits(systime_snapshot.real);
val[2] = upper_32_bits(cycles);
val[3] = lower_32_bits(cycles);
}
static bool kvm_smccc_default_allowed(u32 func_id)
{
switch (func_id) {
/*
* List of function-ids that are not gated with the bitmapped
* feature firmware registers, and are to be allowed for
* servicing the call by default.
*/
case ARM_SMCCC_VERSION_FUNC_ID:
case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
return true;
default:
/* PSCI 0.2 and up is in the 0:0x1f range */
if (ARM_SMCCC_OWNER_NUM(func_id) == ARM_SMCCC_OWNER_STANDARD &&
ARM_SMCCC_FUNC_NUM(func_id) <= 0x1f)
return true;
/*
* KVM's PSCI 0.1 doesn't comply with SMCCC, and has
* its own function-id base and range
*/
if (func_id >= KVM_PSCI_FN(0) && func_id <= KVM_PSCI_FN(3))
return true;
return false;
}
}
static bool kvm_smccc_test_fw_bmap(struct kvm_vcpu *vcpu, u32 func_id)
{
struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
switch (func_id) {
case ARM_SMCCC_TRNG_VERSION:
case ARM_SMCCC_TRNG_FEATURES:
case ARM_SMCCC_TRNG_GET_UUID:
case ARM_SMCCC_TRNG_RND32:
case ARM_SMCCC_TRNG_RND64:
return test_bit(KVM_REG_ARM_STD_BIT_TRNG_V1_0,
&smccc_feat->std_bmap);
case ARM_SMCCC_HV_PV_TIME_FEATURES:
case ARM_SMCCC_HV_PV_TIME_ST:
return test_bit(KVM_REG_ARM_STD_HYP_BIT_PV_TIME,
&smccc_feat->std_hyp_bmap);
case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_FUNC_FEAT,
&smccc_feat->vendor_hyp_bmap);
case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
return test_bit(KVM_REG_ARM_VENDOR_HYP_BIT_PTP,
&smccc_feat->vendor_hyp_bmap);
default:
return false;
}
}
#define SMC32_ARCH_RANGE_BEGIN ARM_SMCCC_VERSION_FUNC_ID
#define SMC32_ARCH_RANGE_END ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
ARM_SMCCC_SMC_32, \
0, ARM_SMCCC_FUNC_MASK)
#define SMC64_ARCH_RANGE_BEGIN ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
ARM_SMCCC_SMC_64, \
0, 0)
#define SMC64_ARCH_RANGE_END ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
ARM_SMCCC_SMC_64, \
0, ARM_SMCCC_FUNC_MASK)
static int kvm_smccc_filter_insert_reserved(struct kvm *kvm)
{
int r;
/*
* Prevent userspace from handling any SMCCC calls in the architecture
* range, avoiding the risk of misrepresenting Spectre mitigation status
* to the guest.
*/
r = mtree_insert_range(&kvm->arch.smccc_filter,
SMC32_ARCH_RANGE_BEGIN, SMC32_ARCH_RANGE_END,
xa_mk_value(KVM_SMCCC_FILTER_HANDLE),
GFP_KERNEL_ACCOUNT);
if (r)
goto out_destroy;
r = mtree_insert_range(&kvm->arch.smccc_filter,
SMC64_ARCH_RANGE_BEGIN, SMC64_ARCH_RANGE_END,
xa_mk_value(KVM_SMCCC_FILTER_HANDLE),
GFP_KERNEL_ACCOUNT);
if (r)
goto out_destroy;
return 0;
out_destroy:
mtree_destroy(&kvm->arch.smccc_filter);
return r;
}
static bool kvm_smccc_filter_configured(struct kvm *kvm)
{
return !mtree_empty(&kvm->arch.smccc_filter);
}
static int kvm_smccc_set_filter(struct kvm *kvm, struct kvm_smccc_filter __user *uaddr)
{
const void *zero_page = page_to_virt(ZERO_PAGE(0));
struct kvm_smccc_filter filter;
u32 start, end;
int r;
if (copy_from_user(&filter, uaddr, sizeof(filter)))
return -EFAULT;
if (memcmp(filter.pad, zero_page, sizeof(filter.pad)))
return -EINVAL;
start = filter.base;
end = start + filter.nr_functions - 1;
if (end < start || filter.action >= NR_SMCCC_FILTER_ACTIONS)
return -EINVAL;
mutex_lock(&kvm->arch.config_lock);
if (kvm_vm_has_ran_once(kvm)) {
r = -EBUSY;
goto out_unlock;
}
if (!kvm_smccc_filter_configured(kvm)) {
r = kvm_smccc_filter_insert_reserved(kvm);
if (WARN_ON_ONCE(r))
goto out_unlock;
}
r = mtree_insert_range(&kvm->arch.smccc_filter, start, end,
xa_mk_value(filter.action), GFP_KERNEL_ACCOUNT);
out_unlock:
mutex_unlock(&kvm->arch.config_lock);
return r;
}
static u8 kvm_smccc_filter_get_action(struct kvm *kvm, u32 func_id)
{
unsigned long idx = func_id;
void *val;
if (!kvm_smccc_filter_configured(kvm))
return KVM_SMCCC_FILTER_HANDLE;
/*
* But where's the error handling, you say?
*
* mt_find() returns NULL if no entry was found, which just so happens
* to match KVM_SMCCC_FILTER_HANDLE.
*/
val = mt_find(&kvm->arch.smccc_filter, &idx, idx);
return xa_to_value(val);
}
static u8 kvm_smccc_get_action(struct kvm_vcpu *vcpu, u32 func_id)
{
/*
* Intervening actions in the SMCCC filter take precedence over the
* pseudo-firmware register bitmaps.
*/
u8 action = kvm_smccc_filter_get_action(vcpu->kvm, func_id);
if (action != KVM_SMCCC_FILTER_HANDLE)
return action;
if (kvm_smccc_test_fw_bmap(vcpu, func_id) ||
kvm_smccc_default_allowed(func_id))
return KVM_SMCCC_FILTER_HANDLE;
return KVM_SMCCC_FILTER_DENY;
}
static void kvm_prepare_hypercall_exit(struct kvm_vcpu *vcpu, u32 func_id)
{
u8 ec = ESR_ELx_EC(kvm_vcpu_get_esr(vcpu));
struct kvm_run *run = vcpu->run;
u64 flags = 0;
if (ec == ESR_ELx_EC_SMC32 || ec == ESR_ELx_EC_SMC64)
flags |= KVM_HYPERCALL_EXIT_SMC;
if (!kvm_vcpu_trap_il_is32bit(vcpu))
flags |= KVM_HYPERCALL_EXIT_16BIT;
run->exit_reason = KVM_EXIT_HYPERCALL;
run->hypercall = (typeof(run->hypercall)) {
.nr = func_id,
.flags = flags,
};
}
int kvm_smccc_call_handler(struct kvm_vcpu *vcpu)
{
struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
u32 func_id = smccc_get_function(vcpu);
u64 val[4] = {SMCCC_RET_NOT_SUPPORTED};
u32 feature;
u8 action;
gpa_t gpa;
action = kvm_smccc_get_action(vcpu, func_id);
switch (action) {
case KVM_SMCCC_FILTER_HANDLE:
break;
case KVM_SMCCC_FILTER_DENY:
goto out;
case KVM_SMCCC_FILTER_FWD_TO_USER:
kvm_prepare_hypercall_exit(vcpu, func_id);
return 0;
default:
WARN_RATELIMIT(1, "Unhandled SMCCC filter action: %d\n", action);
goto out;
}
switch (func_id) {
case ARM_SMCCC_VERSION_FUNC_ID:
val[0] = ARM_SMCCC_VERSION_1_1;
break;
case ARM_SMCCC_ARCH_FEATURES_FUNC_ID:
feature = smccc_get_arg1(vcpu);
switch (feature) {
case ARM_SMCCC_ARCH_WORKAROUND_1:
switch (arm64_get_spectre_v2_state()) {
case SPECTRE_VULNERABLE:
break;
case SPECTRE_MITIGATED:
val[0] = SMCCC_RET_SUCCESS;
break;
case SPECTRE_UNAFFECTED:
val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
break;
}
break;
case ARM_SMCCC_ARCH_WORKAROUND_2:
switch (arm64_get_spectre_v4_state()) {
case SPECTRE_VULNERABLE:
break;
case SPECTRE_MITIGATED:
/*
* SSBS everywhere: Indicate no firmware
* support, as the SSBS support will be
* indicated to the guest and the default is
* safe.
*
* Otherwise, expose a permanent mitigation
* to the guest, and hide SSBS so that the
* guest stays protected.
*/
if (cpus_have_final_cap(ARM64_SSBS))
break;
fallthrough;
case SPECTRE_UNAFFECTED:
val[0] = SMCCC_RET_NOT_REQUIRED;
break;
}
break;
case ARM_SMCCC_ARCH_WORKAROUND_3:
switch (arm64_get_spectre_bhb_state()) {
case SPECTRE_VULNERABLE:
break;
case SPECTRE_MITIGATED:
val[0] = SMCCC_RET_SUCCESS;
break;
case SPECTRE_UNAFFECTED:
val[0] = SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED;
break;
}
break;
case ARM_SMCCC_HV_PV_TIME_FEATURES:
if (test_bit(KVM_REG_ARM_STD_HYP_BIT_PV_TIME,
&smccc_feat->std_hyp_bmap))
val[0] = SMCCC_RET_SUCCESS;
break;
}
break;
case ARM_SMCCC_HV_PV_TIME_FEATURES:
val[0] = kvm_hypercall_pv_features(vcpu);
break;
case ARM_SMCCC_HV_PV_TIME_ST:
gpa = kvm_init_stolen_time(vcpu);
if (gpa != INVALID_GPA)
val[0] = gpa;
break;
case ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID:
val[0] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0;
val[1] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1;
val[2] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2;
val[3] = ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3;
break;
case ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID:
val[0] = smccc_feat->vendor_hyp_bmap;
break;
case ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID:
kvm_ptp_get_time(vcpu, val);
break;
case ARM_SMCCC_TRNG_VERSION:
case ARM_SMCCC_TRNG_FEATURES:
case ARM_SMCCC_TRNG_GET_UUID:
case ARM_SMCCC_TRNG_RND32:
case ARM_SMCCC_TRNG_RND64:
return kvm_trng_call(vcpu);
default:
return kvm_psci_call(vcpu);
}
out:
smccc_set_retval(vcpu, val[0], val[1], val[2], val[3]);
return 1;
}
static const u64 kvm_arm_fw_reg_ids[] = {
KVM_REG_ARM_PSCI_VERSION,
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1,
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2,
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3,
KVM_REG_ARM_STD_BMAP,
KVM_REG_ARM_STD_HYP_BMAP,
KVM_REG_ARM_VENDOR_HYP_BMAP,
};
void kvm_arm_init_hypercalls(struct kvm *kvm)
{
struct kvm_smccc_features *smccc_feat = &kvm->arch.smccc_feat;
smccc_feat->std_bmap = KVM_ARM_SMCCC_STD_FEATURES;
smccc_feat->std_hyp_bmap = KVM_ARM_SMCCC_STD_HYP_FEATURES;
smccc_feat->vendor_hyp_bmap = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
mt_init(&kvm->arch.smccc_filter);
}
void kvm_arm_teardown_hypercalls(struct kvm *kvm)
{
mtree_destroy(&kvm->arch.smccc_filter);
}
int kvm_arm_get_fw_num_regs(struct kvm_vcpu *vcpu)
{
return ARRAY_SIZE(kvm_arm_fw_reg_ids);
}
int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
{
int i;
for (i = 0; i < ARRAY_SIZE(kvm_arm_fw_reg_ids); i++) {
if (put_user(kvm_arm_fw_reg_ids[i], uindices++))
return -EFAULT;
}
return 0;
}
#define KVM_REG_FEATURE_LEVEL_MASK GENMASK(3, 0)
/*
* Convert the workaround level into an easy-to-compare number, where higher
* values mean better protection.
*/
static int get_kernel_wa_level(u64 regid)
{
switch (regid) {
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
switch (arm64_get_spectre_v2_state()) {
case SPECTRE_VULNERABLE:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
case SPECTRE_MITIGATED:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
case SPECTRE_UNAFFECTED:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
}
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
switch (arm64_get_spectre_v4_state()) {
case SPECTRE_MITIGATED:
/*
* As for the hypercall discovery, we pretend we
* don't have any FW mitigation if SSBS is there at
* all times.
*/
if (cpus_have_final_cap(ARM64_SSBS))
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
fallthrough;
case SPECTRE_UNAFFECTED:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
case SPECTRE_VULNERABLE:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
}
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
switch (arm64_get_spectre_bhb_state()) {
case SPECTRE_VULNERABLE:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
case SPECTRE_MITIGATED:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_AVAIL;
case SPECTRE_UNAFFECTED:
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_REQUIRED;
}
return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3_NOT_AVAIL;
}
return -EINVAL;
}
int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
struct kvm_smccc_features *smccc_feat = &vcpu->kvm->arch.smccc_feat;
void __user *uaddr = (void __user *)(long)reg->addr;
u64 val;
switch (reg->id) {
case KVM_REG_ARM_PSCI_VERSION:
val = kvm_psci_version(vcpu);
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
val = get_kernel_wa_level(reg->id) & KVM_REG_FEATURE_LEVEL_MASK;
break;
case KVM_REG_ARM_STD_BMAP:
val = READ_ONCE(smccc_feat->std_bmap);
break;
case KVM_REG_ARM_STD_HYP_BMAP:
val = READ_ONCE(smccc_feat->std_hyp_bmap);
break;
case KVM_REG_ARM_VENDOR_HYP_BMAP:
val = READ_ONCE(smccc_feat->vendor_hyp_bmap);
break;
default:
return -ENOENT;
}
if (copy_to_user(uaddr, &val, KVM_REG_SIZE(reg->id)))
return -EFAULT;
return 0;
}
static int kvm_arm_set_fw_reg_bmap(struct kvm_vcpu *vcpu, u64 reg_id, u64 val)
{
int ret = 0;
struct kvm *kvm = vcpu->kvm;
struct kvm_smccc_features *smccc_feat = &kvm->arch.smccc_feat;
unsigned long *fw_reg_bmap, fw_reg_features;
switch (reg_id) {
case KVM_REG_ARM_STD_BMAP:
fw_reg_bmap = &smccc_feat->std_bmap;
fw_reg_features = KVM_ARM_SMCCC_STD_FEATURES;
break;
case KVM_REG_ARM_STD_HYP_BMAP:
fw_reg_bmap = &smccc_feat->std_hyp_bmap;
fw_reg_features = KVM_ARM_SMCCC_STD_HYP_FEATURES;
break;
case KVM_REG_ARM_VENDOR_HYP_BMAP:
fw_reg_bmap = &smccc_feat->vendor_hyp_bmap;
fw_reg_features = KVM_ARM_SMCCC_VENDOR_HYP_FEATURES;
break;
default:
return -ENOENT;
}
/* Check for unsupported bit */
if (val & ~fw_reg_features)
return -EINVAL;
mutex_lock(&kvm->arch.config_lock);
if (kvm_vm_has_ran_once(kvm) && val != *fw_reg_bmap) {
ret = -EBUSY;
goto out;
}
WRITE_ONCE(*fw_reg_bmap, val);
out:
mutex_unlock(&kvm->arch.config_lock);
return ret;
}
int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
void __user *uaddr = (void __user *)(long)reg->addr;
u64 val;
int wa_level;
if (KVM_REG_SIZE(reg->id) != sizeof(val))
return -ENOENT;
if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
return -EFAULT;
switch (reg->id) {
case KVM_REG_ARM_PSCI_VERSION:
{
bool wants_02;
wants_02 = vcpu_has_feature(vcpu, KVM_ARM_VCPU_PSCI_0_2);
switch (val) {
case KVM_ARM_PSCI_0_1:
if (wants_02)
return -EINVAL;
vcpu->kvm->arch.psci_version = val;
return 0;
case KVM_ARM_PSCI_0_2:
case KVM_ARM_PSCI_1_0:
case KVM_ARM_PSCI_1_1:
if (!wants_02)
return -EINVAL;
vcpu->kvm->arch.psci_version = val;
return 0;
}
break;
}
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_3:
if (val & ~KVM_REG_FEATURE_LEVEL_MASK)
return -EINVAL;
if (get_kernel_wa_level(reg->id) < val)
return -EINVAL;
return 0;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
if (val & ~(KVM_REG_FEATURE_LEVEL_MASK |
KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED))
return -EINVAL;
/* The enabled bit must not be set unless the level is AVAIL. */
if ((val & KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_ENABLED) &&
(val & KVM_REG_FEATURE_LEVEL_MASK) != KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL)
return -EINVAL;
/*
* Map all the possible incoming states to the only two we
* really want to deal with.
*/
switch (val & KVM_REG_FEATURE_LEVEL_MASK) {
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN:
wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
break;
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_AVAIL:
case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED:
wa_level = KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
break;
default:
return -EINVAL;
}
/*
* We can deal with NOT_AVAIL on NOT_REQUIRED, but not the
* other way around.
*/
if (get_kernel_wa_level(reg->id) < wa_level)
return -EINVAL;
return 0;
case KVM_REG_ARM_STD_BMAP:
case KVM_REG_ARM_STD_HYP_BMAP:
case KVM_REG_ARM_VENDOR_HYP_BMAP:
return kvm_arm_set_fw_reg_bmap(vcpu, reg->id, val);
default:
return -ENOENT;
}
return -EINVAL;
}
int kvm_vm_smccc_has_attr(struct kvm *kvm, struct kvm_device_attr *attr)
{
switch (attr->attr) {
case KVM_ARM_VM_SMCCC_FILTER:
return 0;
default:
return -ENXIO;
}
}
int kvm_vm_smccc_set_attr(struct kvm *kvm, struct kvm_device_attr *attr)
{
void __user *uaddr = (void __user *)attr->addr;
switch (attr->attr) {
case KVM_ARM_VM_SMCCC_FILTER:
return kvm_smccc_set_filter(kvm, uaddr);
default:
return -ENXIO;
}
}