kvj
/
linux-zen-server
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
linux-zen-server/arch/arm64/kvm/arm.c

2397 lines
57 KiB
C
Raw Normal View History

Initial commit
2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012 - Virtual Open Systems and Columbia University
* Author: Christoffer Dall <c.dall@virtualopensystems.com>
*/
#include <linux/bug.h>
#include <linux/cpu_pm.h>
#include <linux/entry-kvm.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/mman.h>
#include <linux/sched.h>
#include <linux/kmemleak.h>
#include <linux/kvm.h>
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/sched/stat.h>
#include <linux/psci.h>
#include <trace/events/kvm.h>
#define CREATE_TRACE_POINTS
#include "trace_arm.h"
#include <linux/uaccess.h>
#include <asm/ptrace.h>
#include <asm/mman.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/virt.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_pkvm.h>
#include <asm/kvm_emulate.h>
#include <asm/sections.h>
#include <kvm/arm_hypercalls.h>
#include <kvm/arm_pmu.h>
#include <kvm/arm_psci.h>
static enum kvm_mode kvm_mode = KVM_MODE_DEFAULT;
DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
static bool vgic_present;
static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
DEFINE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
{
return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
}
int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
struct kvm_enable_cap *cap)
{
int r;
if (cap->flags)
return -EINVAL;
switch (cap->cap) {
case KVM_CAP_ARM_NISV_TO_USER:
r = 0;
set_bit(KVM_ARCH_FLAG_RETURN_NISV_IO_ABORT_TO_USER,
&kvm->arch.flags);
break;
case KVM_CAP_ARM_MTE:
mutex_lock(&kvm->lock);
if (!system_supports_mte() || kvm->created_vcpus) {
r = -EINVAL;
} else {
r = 0;
set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags);
}
mutex_unlock(&kvm->lock);
break;
case KVM_CAP_ARM_SYSTEM_SUSPEND:
r = 0;
set_bit(KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED, &kvm->arch.flags);
break;
default:
r = -EINVAL;
break;
}
return r;
}
static int kvm_arm_default_max_vcpus(void)
{
return vgic_present ? kvm_vgic_get_max_vcpus() : KVM_MAX_VCPUS;
}
static void set_default_spectre(struct kvm *kvm)
{
/*
* The default is to expose CSV2 == 1 if the HW isn't affected.
* Although this is a per-CPU feature, we make it global because
* asymmetric systems are just a nuisance.
*
* Userspace can override this as long as it doesn't promise
* the impossible.
*/
if (arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED)
kvm->arch.pfr0_csv2 = 1;
if (arm64_get_meltdown_state() == SPECTRE_UNAFFECTED)
kvm->arch.pfr0_csv3 = 1;
}
/**
* kvm_arch_init_vm - initializes a VM data structure
* @kvm: pointer to the KVM struct
*/
int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
{
int ret;
mutex_init(&kvm->arch.config_lock);
#ifdef CONFIG_LOCKDEP
/* Clue in lockdep that the config_lock must be taken inside kvm->lock */
mutex_lock(&kvm->lock);
mutex_lock(&kvm->arch.config_lock);
mutex_unlock(&kvm->arch.config_lock);
mutex_unlock(&kvm->lock);
#endif
ret = kvm_share_hyp(kvm, kvm + 1);
if (ret)
return ret;
ret = pkvm_init_host_vm(kvm);
if (ret)
goto err_unshare_kvm;
if (!zalloc_cpumask_var(&kvm->arch.supported_cpus, GFP_KERNEL_ACCOUNT)) {
ret = -ENOMEM;
goto err_unshare_kvm;
}
cpumask_copy(kvm->arch.supported_cpus, cpu_possible_mask);
ret = kvm_init_stage2_mmu(kvm, &kvm->arch.mmu, type);
if (ret)
goto err_free_cpumask;
kvm_vgic_early_init(kvm);
/* The maximum number of VCPUs is limited by the host's GIC model */
kvm->max_vcpus = kvm_arm_default_max_vcpus();
set_default_spectre(kvm);
kvm_arm_init_hypercalls(kvm);
/*
* Initialise the default PMUver before there is a chance to
* create an actual PMU.
*/
kvm->arch.dfr0_pmuver.imp = kvm_arm_pmu_get_pmuver_limit();
return 0;
err_free_cpumask:
free_cpumask_var(kvm->arch.supported_cpus);
err_unshare_kvm:
kvm_unshare_hyp(kvm, kvm + 1);
return ret;
}
vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
{
return VM_FAULT_SIGBUS;
}
/**
* kvm_arch_destroy_vm - destroy the VM data structure
* @kvm: pointer to the KVM struct
*/
void kvm_arch_destroy_vm(struct kvm *kvm)
{
kvm_free_stage2_pgd(&kvm->arch.mmu);
bitmap_free(kvm->arch.pmu_filter);
free_cpumask_var(kvm->arch.supported_cpus);
kvm_vgic_destroy(kvm);
if (is_protected_kvm_enabled())
pkvm_destroy_hyp_vm(kvm);
kvm_destroy_vcpus(kvm);
kvm_unshare_hyp(kvm, kvm + 1);
}
int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
{
int r;
switch (ext) {
case KVM_CAP_IRQCHIP:
r = vgic_present;
break;
case KVM_CAP_IOEVENTFD:
case KVM_CAP_DEVICE_CTRL:
case KVM_CAP_USER_MEMORY:
case KVM_CAP_SYNC_MMU:
case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
case KVM_CAP_ONE_REG:
case KVM_CAP_ARM_PSCI:
case KVM_CAP_ARM_PSCI_0_2:
case KVM_CAP_READONLY_MEM:
case KVM_CAP_MP_STATE:
case KVM_CAP_IMMEDIATE_EXIT:
case KVM_CAP_VCPU_EVENTS:
case KVM_CAP_ARM_IRQ_LINE_LAYOUT_2:
case KVM_CAP_ARM_NISV_TO_USER:
case KVM_CAP_ARM_INJECT_EXT_DABT:
case KVM_CAP_SET_GUEST_DEBUG:
case KVM_CAP_VCPU_ATTRIBUTES:
case KVM_CAP_PTP_KVM:
case KVM_CAP_ARM_SYSTEM_SUSPEND:
case KVM_CAP_IRQFD_RESAMPLE:
r = 1;
break;
case KVM_CAP_SET_GUEST_DEBUG2:
return KVM_GUESTDBG_VALID_MASK;
case KVM_CAP_ARM_SET_DEVICE_ADDR:
r = 1;
break;
case KVM_CAP_NR_VCPUS:
/*
* ARM64 treats KVM_CAP_NR_CPUS differently from all other
* architectures, as it does not always bound it to
* KVM_CAP_MAX_VCPUS. It should not matter much because
* this is just an advisory value.
*/
r = min_t(unsigned int, num_online_cpus(),
kvm_arm_default_max_vcpus());
break;
case KVM_CAP_MAX_VCPUS:
case KVM_CAP_MAX_VCPU_ID:
if (kvm)
r = kvm->max_vcpus;
else
r = kvm_arm_default_max_vcpus();
break;
case KVM_CAP_MSI_DEVID:
if (!kvm)
r = -EINVAL;
else
r = kvm->arch.vgic.msis_require_devid;
break;
case KVM_CAP_ARM_USER_IRQ:
/*
* 1: EL1_VTIMER, EL1_PTIMER, and PMU.
* (bump this number if adding more devices)
*/
r = 1;
break;
case KVM_CAP_ARM_MTE:
r = system_supports_mte();
break;
case KVM_CAP_STEAL_TIME:
r = kvm_arm_pvtime_supported();
break;
case KVM_CAP_ARM_EL1_32BIT:
r = cpus_have_const_cap(ARM64_HAS_32BIT_EL1);
break;
case KVM_CAP_GUEST_DEBUG_HW_BPS:
r = get_num_brps();
break;
case KVM_CAP_GUEST_DEBUG_HW_WPS:
r = get_num_wrps();
break;
case KVM_CAP_ARM_PMU_V3:
r = kvm_arm_support_pmu_v3();
break;
case KVM_CAP_ARM_INJECT_SERROR_ESR:
r = cpus_have_const_cap(ARM64_HAS_RAS_EXTN);
break;
case KVM_CAP_ARM_VM_IPA_SIZE:
r = get_kvm_ipa_limit();
break;
case KVM_CAP_ARM_SVE:
r = system_supports_sve();
break;
case KVM_CAP_ARM_PTRAUTH_ADDRESS:
case KVM_CAP_ARM_PTRAUTH_GENERIC:
r = system_has_full_ptr_auth();
break;
default:
r = 0;
}
return r;
}
long kvm_arch_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
return -EINVAL;
}
struct kvm *kvm_arch_alloc_vm(void)
{
size_t sz = sizeof(struct kvm);
if (!has_vhe())
return kzalloc(sz, GFP_KERNEL_ACCOUNT);
return __vmalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_HIGHMEM | __GFP_ZERO);
}
int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
{
if (irqchip_in_kernel(kvm) && vgic_initialized(kvm))
return -EBUSY;
if (id >= kvm->max_vcpus)
return -EINVAL;
return 0;
}
int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
int err;
spin_lock_init(&vcpu->arch.mp_state_lock);
#ifdef CONFIG_LOCKDEP
/* Inform lockdep that the config_lock is acquired after vcpu->mutex */
mutex_lock(&vcpu->mutex);
mutex_lock(&vcpu->kvm->arch.config_lock);
mutex_unlock(&vcpu->kvm->arch.config_lock);
mutex_unlock(&vcpu->mutex);
#endif
/* Force users to call KVM_ARM_VCPU_INIT */
vcpu->arch.target = -1;
bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
/*
* Default value for the FP state, will be overloaded at load
* time if we support FP (pretty likely)
*/
vcpu->arch.fp_state = FP_STATE_FREE;
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
kvm_pmu_vcpu_init(vcpu);
kvm_arm_reset_debug_ptr(vcpu);
kvm_arm_pvtime_vcpu_init(&vcpu->arch);
vcpu->arch.hw_mmu = &vcpu->kvm->arch.mmu;
err = kvm_vgic_vcpu_init(vcpu);
if (err)
return err;
return kvm_share_hyp(vcpu, vcpu + 1);
}
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
}
void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
{
if (vcpu_has_run_once(vcpu) && unlikely(!irqchip_in_kernel(vcpu->kvm)))
static_branch_dec(&userspace_irqchip_in_use);
kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
kvm_timer_vcpu_terminate(vcpu);
kvm_pmu_vcpu_destroy(vcpu);
kvm_arm_vcpu_destroy(vcpu);
}
void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu)
{
}
void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu)
{
}
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct kvm_s2_mmu *mmu;
int *last_ran;
mmu = vcpu->arch.hw_mmu;
last_ran = this_cpu_ptr(mmu->last_vcpu_ran);
/*
* We guarantee that both TLBs and I-cache are private to each
* vcpu. If detecting that a vcpu from the same VM has
* previously run on the same physical CPU, call into the
* hypervisor code to nuke the relevant contexts.
*
* We might get preempted before the vCPU actually runs, but
* over-invalidation doesn't affect correctness.
*/
if (*last_ran != vcpu->vcpu_id) {
kvm_call_hyp(__kvm_flush_cpu_context, mmu);
*last_ran = vcpu->vcpu_id;
}
vcpu->cpu = cpu;
kvm_vgic_load(vcpu);
kvm_timer_vcpu_load(vcpu);
if (has_vhe())
kvm_vcpu_load_sysregs_vhe(vcpu);
kvm_arch_vcpu_load_fp(vcpu);
kvm_vcpu_pmu_restore_guest(vcpu);
if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
if (single_task_running())
vcpu_clear_wfx_traps(vcpu);
else
vcpu_set_wfx_traps(vcpu);
if (vcpu_has_ptrauth(vcpu))
vcpu_ptrauth_disable(vcpu);
kvm_arch_vcpu_load_debug_state_flags(vcpu);
if (!cpumask_test_cpu(smp_processor_id(), vcpu->kvm->arch.supported_cpus))
vcpu_set_on_unsupported_cpu(vcpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvm_arch_vcpu_put_debug_state_flags(vcpu);
kvm_arch_vcpu_put_fp(vcpu);
if (has_vhe())
kvm_vcpu_put_sysregs_vhe(vcpu);
kvm_timer_vcpu_put(vcpu);
kvm_vgic_put(vcpu);
kvm_vcpu_pmu_restore_host(vcpu);
kvm_arm_vmid_clear_active();
vcpu_clear_on_unsupported_cpu(vcpu);
vcpu->cpu = -1;
}
static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
{
WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_STOPPED);
kvm_make_request(KVM_REQ_SLEEP, vcpu);
kvm_vcpu_kick(vcpu);
}
void kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
{
spin_lock(&vcpu->arch.mp_state_lock);
__kvm_arm_vcpu_power_off(vcpu);
spin_unlock(&vcpu->arch.mp_state_lock);
}
bool kvm_arm_vcpu_stopped(struct kvm_vcpu *vcpu)
{
return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_STOPPED;
}
static void kvm_arm_vcpu_suspend(struct kvm_vcpu *vcpu)
{
WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_SUSPENDED);
kvm_make_request(KVM_REQ_SUSPEND, vcpu);
kvm_vcpu_kick(vcpu);
}
static bool kvm_arm_vcpu_suspended(struct kvm_vcpu *vcpu)
{
return READ_ONCE(vcpu->arch.mp_state.mp_state) == KVM_MP_STATE_SUSPENDED;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
*mp_state = READ_ONCE(vcpu->arch.mp_state);
return 0;
}
int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
struct kvm_mp_state *mp_state)
{
int ret = 0;
spin_lock(&vcpu->arch.mp_state_lock);
switch (mp_state->mp_state) {
case KVM_MP_STATE_RUNNABLE:
WRITE_ONCE(vcpu->arch.mp_state, *mp_state);
break;
case KVM_MP_STATE_STOPPED:
__kvm_arm_vcpu_power_off(vcpu);
break;
case KVM_MP_STATE_SUSPENDED:
kvm_arm_vcpu_suspend(vcpu);
break;
default:
ret = -EINVAL;
}
spin_unlock(&vcpu->arch.mp_state_lock);
return ret;
}
/**
* kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
* @v: The VCPU pointer
*
* If the guest CPU is not waiting for interrupts or an interrupt line is
* asserted, the CPU is by definition runnable.
*/
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
bool irq_lines = *vcpu_hcr(v) & (HCR_VI | HCR_VF);
return ((irq_lines || kvm_vgic_vcpu_pending_irq(v))
&& !kvm_arm_vcpu_stopped(v) && !v->arch.pause);
}
bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu)
{
return vcpu_mode_priv(vcpu);
}
#ifdef CONFIG_GUEST_PERF_EVENTS
unsigned long kvm_arch_vcpu_get_ip(struct kvm_vcpu *vcpu)
{
return *vcpu_pc(vcpu);
}
#endif
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
{
return vcpu->arch.target >= 0;
}
/*
* Handle both the initialisation that is being done when the vcpu is
* run for the first time, as well as the updates that must be
* performed each time we get a new thread dealing with this vcpu.
*/
int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = vcpu->kvm;
int ret;
if (!kvm_vcpu_initialized(vcpu))
return -ENOEXEC;
if (!kvm_arm_vcpu_is_finalized(vcpu))
return -EPERM;
ret = kvm_arch_vcpu_run_map_fp(vcpu);
if (ret)
return ret;
if (likely(vcpu_has_run_once(vcpu)))
return 0;
kvm_arm_vcpu_init_debug(vcpu);
if (likely(irqchip_in_kernel(kvm))) {
/*
* Map the VGIC hardware resources before running a vcpu the
* first time on this VM.
*/
ret = kvm_vgic_map_resources(kvm);
if (ret)
return ret;
}
ret = kvm_timer_enable(vcpu);
if (ret)
return ret;
ret = kvm_arm_pmu_v3_enable(vcpu);
if (ret)
return ret;
if (is_protected_kvm_enabled()) {
ret = pkvm_create_hyp_vm(kvm);
if (ret)
return ret;
}
if (!irqchip_in_kernel(kvm)) {
/*
* Tell the rest of the code that there are userspace irqchip
* VMs in the wild.
*/
static_branch_inc(&userspace_irqchip_in_use);
}
/*
* Initialize traps for protected VMs.
* NOTE: Move to run in EL2 directly, rather than via a hypercall, once
* the code is in place for first run initialization at EL2.
*/
if (kvm_vm_is_protected(kvm))
kvm_call_hyp_nvhe(__pkvm_vcpu_init_traps, vcpu);
mutex_lock(&kvm->arch.config_lock);
set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
mutex_unlock(&kvm->arch.config_lock);
return ret;
}
bool kvm_arch_intc_initialized(struct kvm *kvm)
{
return vgic_initialized(kvm);
}
void kvm_arm_halt_guest(struct kvm *kvm)
{
unsigned long i;
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm)
vcpu->arch.pause = true;
kvm_make_all_cpus_request(kvm, KVM_REQ_SLEEP);
}
void kvm_arm_resume_guest(struct kvm *kvm)
{
unsigned long i;
struct kvm_vcpu *vcpu;
kvm_for_each_vcpu(i, vcpu, kvm) {
vcpu->arch.pause = false;
__kvm_vcpu_wake_up(vcpu);
}
}
static void kvm_vcpu_sleep(struct kvm_vcpu *vcpu)
{
struct rcuwait *wait = kvm_arch_vcpu_get_wait(vcpu);
rcuwait_wait_event(wait,
(!kvm_arm_vcpu_stopped(vcpu)) && (!vcpu->arch.pause),
TASK_INTERRUPTIBLE);
if (kvm_arm_vcpu_stopped(vcpu) || vcpu->arch.pause) {
/* Awaken to handle a signal, request we sleep again later. */
kvm_make_request(KVM_REQ_SLEEP, vcpu);
}
/*
* Make sure we will observe a potential reset request if we've
* observed a change to the power state. Pairs with the smp_wmb() in
* kvm_psci_vcpu_on().
*/
smp_rmb();
}
/**
* kvm_vcpu_wfi - emulate Wait-For-Interrupt behavior
* @vcpu: The VCPU pointer
*
* Suspend execution of a vCPU until a valid wake event is detected, i.e. until
* the vCPU is runnable. The vCPU may or may not be scheduled out, depending
* on when a wake event arrives, e.g. there may already be a pending wake event.
*/
void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
{
/*
* Sync back the state of the GIC CPU interface so that we have
* the latest PMR and group enables. This ensures that
* kvm_arch_vcpu_runnable has up-to-date data to decide whether
* we have pending interrupts, e.g. when determining if the
* vCPU should block.
*
* For the same reason, we want to tell GICv4 that we need
* doorbells to be signalled, should an interrupt become pending.
*/
preempt_disable();
kvm_vgic_vmcr_sync(vcpu);
vgic_v4_put(vcpu, true);
preempt_enable();
kvm_vcpu_halt(vcpu);
vcpu_clear_flag(vcpu, IN_WFIT);
preempt_disable();
vgic_v4_load(vcpu);
preempt_enable();
}
static int kvm_vcpu_suspend(struct kvm_vcpu *vcpu)
{
if (!kvm_arm_vcpu_suspended(vcpu))
return 1;
kvm_vcpu_wfi(vcpu);
/*
* The suspend state is sticky; we do not leave it until userspace
* explicitly marks the vCPU as runnable. Request that we suspend again
* later.
*/
kvm_make_request(KVM_REQ_SUSPEND, vcpu);
/*
* Check to make sure the vCPU is actually runnable. If so, exit to
* userspace informing it of the wakeup condition.
*/
if (kvm_arch_vcpu_runnable(vcpu)) {
memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
vcpu->run->system_event.type = KVM_SYSTEM_EVENT_WAKEUP;
vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
return 0;
}
/*
* Otherwise, we were unblocked to process a different event, such as a
* pending signal. Return 1 and allow kvm_arch_vcpu_ioctl_run() to
* process the event.
*/
return 1;
}
/**
* check_vcpu_requests - check and handle pending vCPU requests
* @vcpu: the VCPU pointer
*
* Return: 1 if we should enter the guest
* 0 if we should exit to userspace
* < 0 if we should exit to userspace, where the return value indicates
* an error
*/
static int check_vcpu_requests(struct kvm_vcpu *vcpu)
{
if (kvm_request_pending(vcpu)) {
if (kvm_check_request(KVM_REQ_SLEEP, vcpu))
kvm_vcpu_sleep(vcpu);
if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
kvm_reset_vcpu(vcpu);
/*
* Clear IRQ_PENDING requests that were made to guarantee
* that a VCPU sees new virtual interrupts.
*/
kvm_check_request(KVM_REQ_IRQ_PENDING, vcpu);
if (kvm_check_request(KVM_REQ_RECORD_STEAL, vcpu))
kvm_update_stolen_time(vcpu);
if (kvm_check_request(KVM_REQ_RELOAD_GICv4, vcpu)) {
/* The distributor enable bits were changed */
preempt_disable();
vgic_v4_put(vcpu, false);
vgic_v4_load(vcpu);
preempt_enable();
}
if (kvm_check_request(KVM_REQ_RELOAD_PMU, vcpu))
kvm_pmu_handle_pmcr(vcpu,
__vcpu_sys_reg(vcpu, PMCR_EL0));
if (kvm_check_request(KVM_REQ_SUSPEND, vcpu))
return kvm_vcpu_suspend(vcpu);
if (kvm_dirty_ring_check_request(vcpu))
return 0;
}
return 1;
}
static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu)
{
if (likely(!vcpu_mode_is_32bit(vcpu)))
return false;
return !kvm_supports_32bit_el0();
}
/**
* kvm_vcpu_exit_request - returns true if the VCPU should *not* enter the guest
* @vcpu: The VCPU pointer
* @ret: Pointer to write optional return code
*
* Returns: true if the VCPU needs to return to a preemptible + interruptible
* and skip guest entry.
*
* This function disambiguates between two different types of exits: exits to a
* preemptible + interruptible kernel context and exits to userspace. For an
* exit to userspace, this function will write the return code to ret and return
* true. For an exit to preemptible + interruptible kernel context (i.e. check
* for pending work and re-enter), return true without writing to ret.
*/
static bool kvm_vcpu_exit_request(struct kvm_vcpu *vcpu, int *ret)
{
struct kvm_run *run = vcpu->run;
/*
* If we're using a userspace irqchip, then check if we need
* to tell a userspace irqchip about timer or PMU level
* changes and if so, exit to userspace (the actual level
* state gets updated in kvm_timer_update_run and
* kvm_pmu_update_run below).
*/
if (static_branch_unlikely(&userspace_irqchip_in_use)) {
if (kvm_timer_should_notify_user(vcpu) ||
kvm_pmu_should_notify_user(vcpu)) {
*ret = -EINTR;
run->exit_reason = KVM_EXIT_INTR;
return true;
}
}
if (unlikely(vcpu_on_unsupported_cpu(vcpu))) {
run->exit_reason = KVM_EXIT_FAIL_ENTRY;
run->fail_entry.hardware_entry_failure_reason = KVM_EXIT_FAIL_ENTRY_CPU_UNSUPPORTED;
run->fail_entry.cpu = smp_processor_id();
*ret = 0;
return true;
}
return kvm_request_pending(vcpu) ||
xfer_to_guest_mode_work_pending();
}
/*
* Actually run the vCPU, entering an RCU extended quiescent state (EQS) while
* the vCPU is running.
*
* This must be noinstr as instrumentation may make use of RCU, and this is not
* safe during the EQS.
*/
static int noinstr kvm_arm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
{
int ret;
guest_state_enter_irqoff();
ret = kvm_call_hyp_ret(__kvm_vcpu_run, vcpu);
guest_state_exit_irqoff();
return ret;
}
/**
* kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
* @vcpu: The VCPU pointer
*
* This function is called through the VCPU_RUN ioctl called from user space. It
* will execute VM code in a loop until the time slice for the process is used
* or some emulation is needed from user space in which case the function will
* return with return value 0 and with the kvm_run structure filled in with the
* required data for the requested emulation.
*/
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
int ret;
if (run->exit_reason == KVM_EXIT_MMIO) {
ret = kvm_handle_mmio_return(vcpu);
if (ret)
return ret;
}
vcpu_load(vcpu);
if (run->immediate_exit) {
ret = -EINTR;
goto out;
}
kvm_sigset_activate(vcpu);
ret = 1;
run->exit_reason = KVM_EXIT_UNKNOWN;
run->flags = 0;
while (ret > 0) {
/*
* Check conditions before entering the guest
*/
ret = xfer_to_guest_mode_handle_work(vcpu);
if (!ret)
ret = 1;
if (ret > 0)
ret = check_vcpu_requests(vcpu);
/*
* Preparing the interrupts to be injected also
* involves poking the GIC, which must be done in a
* non-preemptible context.
*/
preempt_disable();
/*
* The VMID allocator only tracks active VMIDs per
* physical CPU, and therefore the VMID allocated may not be
* preserved on VMID roll-over if the task was preempted,
* making a thread's VMID inactive. So we need to call
* kvm_arm_vmid_update() in non-premptible context.
*/
kvm_arm_vmid_update(&vcpu->arch.hw_mmu->vmid);
kvm_pmu_flush_hwstate(vcpu);
local_irq_disable();
kvm_vgic_flush_hwstate(vcpu);
kvm_pmu_update_vcpu_events(vcpu);
/*
* Ensure we set mode to IN_GUEST_MODE after we disable
* interrupts and before the final VCPU requests check.
* See the comment in kvm_vcpu_exiting_guest_mode() and
* Documentation/virt/kvm/vcpu-requests.rst
*/
smp_store_mb(vcpu->mode, IN_GUEST_MODE);
if (ret <= 0 || kvm_vcpu_exit_request(vcpu, &ret)) {
vcpu->mode = OUTSIDE_GUEST_MODE;
isb(); /* Ensure work in x_flush_hwstate is committed */
kvm_pmu_sync_hwstate(vcpu);
if (static_branch_unlikely(&userspace_irqchip_in_use))
kvm_timer_sync_user(vcpu);
kvm_vgic_sync_hwstate(vcpu);
local_irq_enable();
preempt_enable();
continue;
}
kvm_arm_setup_debug(vcpu);
kvm_arch_vcpu_ctxflush_fp(vcpu);
/**************************************************************
* Enter the guest
*/
trace_kvm_entry(*vcpu_pc(vcpu));
guest_timing_enter_irqoff();
ret = kvm_arm_vcpu_enter_exit(vcpu);
vcpu->mode = OUTSIDE_GUEST_MODE;
vcpu->stat.exits++;
/*
* Back from guest
*************************************************************/
kvm_arm_clear_debug(vcpu);
/*
* We must sync the PMU state before the vgic state so
* that the vgic can properly sample the updated state of the
* interrupt line.
*/
kvm_pmu_sync_hwstate(vcpu);
/*
* Sync the vgic state before syncing the timer state because
* the timer code needs to know if the virtual timer
* interrupts are active.
*/
kvm_vgic_sync_hwstate(vcpu);
/*
* Sync the timer hardware state before enabling interrupts as
* we don't want vtimer interrupts to race with syncing the
* timer virtual interrupt state.
*/
if (static_branch_unlikely(&userspace_irqchip_in_use))
kvm_timer_sync_user(vcpu);
kvm_arch_vcpu_ctxsync_fp(vcpu);
/*
* We must ensure that any pending interrupts are taken before
* we exit guest timing so that timer ticks are accounted as
* guest time. Transiently unmask interrupts so that any
* pending interrupts are taken.
*
* Per ARM DDI 0487G.b section D1.13.4, an ISB (or other
* context synchronization event) is necessary to ensure that
* pending interrupts are taken.
*/
if (ARM_EXCEPTION_CODE(ret) == ARM_EXCEPTION_IRQ) {
local_irq_enable();
isb();
local_irq_disable();
}
guest_timing_exit_irqoff();
local_irq_enable();
trace_kvm_exit(ret, kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
/* Exit types that need handling before we can be preempted */
handle_exit_early(vcpu, ret);
preempt_enable();
/*
* The ARMv8 architecture doesn't give the hypervisor
* a mechanism to prevent a guest from dropping to AArch32 EL0
* if implemented by the CPU. If we spot the guest in such
* state and that we decided it wasn't supposed to do so (like
* with the asymmetric AArch32 case), return to userspace with
* a fatal error.
*/
if (vcpu_mode_is_bad_32bit(vcpu)) {
/*
* As we have caught the guest red-handed, decide that
* it isn't fit for purpose anymore by making the vcpu
* invalid. The VMM can try and fix it by issuing a
* KVM_ARM_VCPU_INIT if it really wants to.
*/
vcpu->arch.target = -1;
ret = ARM_EXCEPTION_IL;
}
ret = handle_exit(vcpu, ret);
}
/* Tell userspace about in-kernel device output levels */
if (unlikely(!irqchip_in_kernel(vcpu->kvm))) {
kvm_timer_update_run(vcpu);
kvm_pmu_update_run(vcpu);
}
kvm_sigset_deactivate(vcpu);
out:
/*
* In the unlikely event that we are returning to userspace
* with pending exceptions or PC adjustment, commit these
* adjustments in order to give userspace a consistent view of
* the vcpu state. Note that this relies on __kvm_adjust_pc()
* being preempt-safe on VHE.
*/
if (unlikely(vcpu_get_flag(vcpu, PENDING_EXCEPTION) ||
vcpu_get_flag(vcpu, INCREMENT_PC)))
kvm_call_hyp(__kvm_adjust_pc, vcpu);
vcpu_put(vcpu);
return ret;
}
static int vcpu_interrupt_line(struct kvm_vcpu *vcpu, int number, bool level)
{
int bit_index;
bool set;
unsigned long *hcr;
if (number == KVM_ARM_IRQ_CPU_IRQ)
bit_index = __ffs(HCR_VI);
else /* KVM_ARM_IRQ_CPU_FIQ */
bit_index = __ffs(HCR_VF);
hcr = vcpu_hcr(vcpu);
if (level)
set = test_and_set_bit(bit_index, hcr);
else
set = test_and_clear_bit(bit_index, hcr);
/*
* If we didn't change anything, no need to wake up or kick other CPUs
*/
if (set == level)
return 0;
/*
* The vcpu irq_lines field was updated, wake up sleeping VCPUs and
* trigger a world-switch round on the running physical CPU to set the
* virtual IRQ/FIQ fields in the HCR appropriately.
*/
kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu);
kvm_vcpu_kick(vcpu);
return 0;
}
int kvm_vm_ioctl_irq_line(struct kvm *kvm, struct kvm_irq_level *irq_level,
bool line_status)
{
u32 irq = irq_level->irq;
unsigned int irq_type, vcpu_idx, irq_num;
int nrcpus = atomic_read(&kvm->online_vcpus);
struct kvm_vcpu *vcpu = NULL;
bool level = irq_level->level;
irq_type = (irq >> KVM_ARM_IRQ_TYPE_SHIFT) & KVM_ARM_IRQ_TYPE_MASK;
vcpu_idx = (irq >> KVM_ARM_IRQ_VCPU_SHIFT) & KVM_ARM_IRQ_VCPU_MASK;
vcpu_idx += ((irq >> KVM_ARM_IRQ_VCPU2_SHIFT) & KVM_ARM_IRQ_VCPU2_MASK) * (KVM_ARM_IRQ_VCPU_MASK + 1);
irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;
trace_kvm_irq_line(irq_type, vcpu_idx, irq_num, irq_level->level);
switch (irq_type) {
case KVM_ARM_IRQ_TYPE_CPU:
if (irqchip_in_kernel(kvm))
return -ENXIO;
if (vcpu_idx >= nrcpus)
return -EINVAL;
vcpu = kvm_get_vcpu(kvm, vcpu_idx);
if (!vcpu)
return -EINVAL;
if (irq_num > KVM_ARM_IRQ_CPU_FIQ)
return -EINVAL;
return vcpu_interrupt_line(vcpu, irq_num, level);
case KVM_ARM_IRQ_TYPE_PPI:
if (!irqchip_in_kernel(kvm))
return -ENXIO;
if (vcpu_idx >= nrcpus)
return -EINVAL;
vcpu = kvm_get_vcpu(kvm, vcpu_idx);
if (!vcpu)
return -EINVAL;
if (irq_num < VGIC_NR_SGIS || irq_num >= VGIC_NR_PRIVATE_IRQS)
return -EINVAL;
return kvm_vgic_inject_irq(kvm, vcpu->vcpu_id, irq_num, level, NULL);
case KVM_ARM_IRQ_TYPE_SPI:
if (!irqchip_in_kernel(kvm))
return -ENXIO;
if (irq_num < VGIC_NR_PRIVATE_IRQS)
return -EINVAL;
return kvm_vgic_inject_irq(kvm, 0, irq_num, level, NULL);
}
return -EINVAL;
}
static int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
const struct kvm_vcpu_init *init)
{
unsigned int i, ret;
u32 phys_target = kvm_target_cpu();
if (init->target != phys_target)
return -EINVAL;
/*
* Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
* use the same target.
*/
if (vcpu->arch.target != -1 && vcpu->arch.target != init->target)
return -EINVAL;
/* -ENOENT for unknown features, -EINVAL for invalid combinations. */
for (i = 0; i < sizeof(init->features) * 8; i++) {
bool set = (init->features[i / 32] & (1 << (i % 32)));
if (set && i >= KVM_VCPU_MAX_FEATURES)
return -ENOENT;
/*
* Secondary and subsequent calls to KVM_ARM_VCPU_INIT must
* use the same feature set.
*/
if (vcpu->arch.target != -1 && i < KVM_VCPU_MAX_FEATURES &&
test_bit(i, vcpu->arch.features) != set)
return -EINVAL;
if (set)
set_bit(i, vcpu->arch.features);
}
vcpu->arch.target = phys_target;
/* Now we know what it is, we can reset it. */
ret = kvm_reset_vcpu(vcpu);
if (ret) {
vcpu->arch.target = -1;
bitmap_zero(vcpu->arch.features, KVM_VCPU_MAX_FEATURES);
}
return ret;
}
static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
struct kvm_vcpu_init *init)
{
int ret;
ret = kvm_vcpu_set_target(vcpu, init);
if (ret)
return ret;
/*
* Ensure a rebooted VM will fault in RAM pages and detect if the
* guest MMU is turned off and flush the caches as needed.
*
* S2FWB enforces all memory accesses to RAM being cacheable,
* ensuring that the data side is always coherent. We still
* need to invalidate the I-cache though, as FWB does *not*
* imply CTR_EL0.DIC.
*/
if (vcpu_has_run_once(vcpu)) {
if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB))
stage2_unmap_vm(vcpu->kvm);
else
icache_inval_all_pou();
}
vcpu_reset_hcr(vcpu);
vcpu->arch.cptr_el2 = CPTR_EL2_DEFAULT;
/*
* Handle the "start in power-off" case.
*/
if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features))
kvm_arm_vcpu_power_off(vcpu);
else
WRITE_ONCE(vcpu->arch.mp_state.mp_state, KVM_MP_STATE_RUNNABLE);
return 0;
}
static int kvm_arm_vcpu_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret = -ENXIO;
switch (attr->group) {
default:
ret = kvm_arm_vcpu_arch_set_attr(vcpu, attr);
break;
}
return ret;
}
static int kvm_arm_vcpu_get_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret = -ENXIO;
switch (attr->group) {
default:
ret = kvm_arm_vcpu_arch_get_attr(vcpu, attr);
break;
}
return ret;
}
static int kvm_arm_vcpu_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{
int ret = -ENXIO;
switch (attr->group) {
default:
ret = kvm_arm_vcpu_arch_has_attr(vcpu, attr);
break;
}
return ret;
}
static int kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
struct kvm_vcpu_events *events)
{
memset(events, 0, sizeof(*events));
return __kvm_arm_vcpu_get_events(vcpu, events);
}
static int kvm_arm_vcpu_set_events(struct kvm_vcpu *vcpu,
struct kvm_vcpu_events *events)
{
int i;
/* check whether the reserved field is zero */
for (i = 0; i < ARRAY_SIZE(events->reserved); i++)
if (events->reserved[i])
return -EINVAL;
/* check whether the pad field is zero */
for (i = 0; i < ARRAY_SIZE(events->exception.pad); i++)
if (events->exception.pad[i])
return -EINVAL;
return __kvm_arm_vcpu_set_events(vcpu, events);
}
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm_vcpu *vcpu = filp->private_data;
void __user *argp = (void __user *)arg;
struct kvm_device_attr attr;
long r;
switch (ioctl) {
case KVM_ARM_VCPU_INIT: {
struct kvm_vcpu_init init;
r = -EFAULT;
if (copy_from_user(&init, argp, sizeof(init)))
break;
r = kvm_arch_vcpu_ioctl_vcpu_init(vcpu, &init);
break;
}
case KVM_SET_ONE_REG:
case KVM_GET_ONE_REG: {
struct kvm_one_reg reg;
r = -ENOEXEC;
if (unlikely(!kvm_vcpu_initialized(vcpu)))
break;
r = -EFAULT;
if (copy_from_user(&reg, argp, sizeof(reg)))
break;
/*
* We could owe a reset due to PSCI. Handle the pending reset
* here to ensure userspace register accesses are ordered after
* the reset.
*/
if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu))
kvm_reset_vcpu(vcpu);
if (ioctl == KVM_SET_ONE_REG)
r = kvm_arm_set_reg(vcpu, &reg);
else
r = kvm_arm_get_reg(vcpu, &reg);
break;
}
case KVM_GET_REG_LIST: {
struct kvm_reg_list __user *user_list = argp;
struct kvm_reg_list reg_list;
unsigned n;
r = -ENOEXEC;
if (unlikely(!kvm_vcpu_initialized(vcpu)))
break;
r = -EPERM;
if (!kvm_arm_vcpu_is_finalized(vcpu))
break;
r = -EFAULT;
if (copy_from_user(&reg_list, user_list, sizeof(reg_list)))
break;
n = reg_list.n;
reg_list.n = kvm_arm_num_regs(vcpu);
if (copy_to_user(user_list, &reg_list, sizeof(reg_list)))
break;
r = -E2BIG;
if (n < reg_list.n)
break;
r = kvm_arm_copy_reg_indices(vcpu, user_list->reg);
break;
}
case KVM_SET_DEVICE_ATTR: {
r = -EFAULT;
if (copy_from_user(&attr, argp, sizeof(attr)))
break;
r = kvm_arm_vcpu_set_attr(vcpu, &attr);
break;
}
case KVM_GET_DEVICE_ATTR: {
r = -EFAULT;
if (copy_from_user(&attr, argp, sizeof(attr)))
break;
r = kvm_arm_vcpu_get_attr(vcpu, &attr);
break;
}
case KVM_HAS_DEVICE_ATTR: {
r = -EFAULT;
if (copy_from_user(&attr, argp, sizeof(attr)))
break;
r = kvm_arm_vcpu_has_attr(vcpu, &attr);
break;
}
case KVM_GET_VCPU_EVENTS: {
struct kvm_vcpu_events events;
if (kvm_arm_vcpu_get_events(vcpu, &events))
return -EINVAL;
if (copy_to_user(argp, &events, sizeof(events)))
return -EFAULT;
return 0;
}
case KVM_SET_VCPU_EVENTS: {
struct kvm_vcpu_events events;
if (copy_from_user(&events, argp, sizeof(events)))
return -EFAULT;
return kvm_arm_vcpu_set_events(vcpu, &events);
}
case KVM_ARM_VCPU_FINALIZE: {
int what;
if (!kvm_vcpu_initialized(vcpu))
return -ENOEXEC;
if (get_user(what, (const int __user *)argp))
return -EFAULT;
return kvm_arm_vcpu_finalize(vcpu, what);
}
default:
r = -EINVAL;
}
return r;
}
void kvm_arch_sync_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot)
{
}
void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
const struct kvm_memory_slot *memslot)
{
kvm_flush_remote_tlbs(kvm);
}
static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
struct kvm_arm_device_addr *dev_addr)
{
switch (FIELD_GET(KVM_ARM_DEVICE_ID_MASK, dev_addr->id)) {
case KVM_ARM_DEVICE_VGIC_V2:
if (!vgic_present)
return -ENXIO;
return kvm_set_legacy_vgic_v2_addr(kvm, dev_addr);
default:
return -ENODEV;
}
}
long kvm_arch_vm_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
struct kvm *kvm = filp->private_data;
void __user *argp = (void __user *)arg;
switch (ioctl) {
case KVM_CREATE_IRQCHIP: {
int ret;
if (!vgic_present)
return -ENXIO;
mutex_lock(&kvm->lock);
ret = kvm_vgic_create(kvm, KVM_DEV_TYPE_ARM_VGIC_V2);
mutex_unlock(&kvm->lock);
return ret;
}
case KVM_ARM_SET_DEVICE_ADDR: {
struct kvm_arm_device_addr dev_addr;
if (copy_from_user(&dev_addr, argp, sizeof(dev_addr)))
return -EFAULT;
return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
}
case KVM_ARM_PREFERRED_TARGET: {
struct kvm_vcpu_init init;
kvm_vcpu_preferred_target(&init);
if (copy_to_user(argp, &init, sizeof(init)))
return -EFAULT;
return 0;
}
case KVM_ARM_MTE_COPY_TAGS: {
struct kvm_arm_copy_mte_tags copy_tags;
if (copy_from_user(&copy_tags, argp, sizeof(copy_tags)))
return -EFAULT;
return kvm_vm_ioctl_mte_copy_tags(kvm, &copy_tags);
}
default:
return -EINVAL;
}
}
static unsigned long nvhe_percpu_size(void)
{
return (unsigned long)CHOOSE_NVHE_SYM(__per_cpu_end) -
(unsigned long)CHOOSE_NVHE_SYM(__per_cpu_start);
}
static unsigned long nvhe_percpu_order(void)
{
unsigned long size = nvhe_percpu_size();
return size ? get_order(size) : 0;
}
/* A lookup table holding the hypervisor VA for each vector slot */
static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS];
static void kvm_init_vector_slot(void *base, enum arm64_hyp_spectre_vector slot)
{
hyp_spectre_vector_selector[slot] = __kvm_vector_slot2addr(base, slot);
}
static int kvm_init_vector_slots(void)
{
int err;
void *base;
base = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
kvm_init_vector_slot(base, HYP_VECTOR_DIRECT);
base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT);
if (kvm_system_needs_idmapped_vectors() &&
!is_protected_kvm_enabled()) {
err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs),
__BP_HARDEN_HYP_VECS_SZ, &base);
if (err)
return err;
}
kvm_init_vector_slot(base, HYP_VECTOR_INDIRECT);
kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_INDIRECT);
return 0;
}
static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits)
{
struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
unsigned long tcr;
/*
* Calculate the raw per-cpu offset without a translation from the
* kernel's mapping to the linear mapping, and store it in tpidr_el2
* so that we can use adr_l to access per-cpu variables in EL2.
* Also drop the KASAN tag which gets in the way...
*/
params->tpidr_el2 = (unsigned long)kasan_reset_tag(per_cpu_ptr_nvhe_sym(__per_cpu_start, cpu)) -
(unsigned long)kvm_ksym_ref(CHOOSE_NVHE_SYM(__per_cpu_start));
params->mair_el2 = read_sysreg(mair_el1);
tcr = (read_sysreg(tcr_el1) & TCR_EL2_MASK) | TCR_EL2_RES1;
tcr &= ~TCR_T0SZ_MASK;
tcr |= TCR_T0SZ(hyp_va_bits);
params->tcr_el2 = tcr;
params->pgd_pa = kvm_mmu_get_httbr();
if (is_protected_kvm_enabled())
params->hcr_el2 = HCR_HOST_NVHE_PROTECTED_FLAGS;
else
params->hcr_el2 = HCR_HOST_NVHE_FLAGS;
params->vttbr = params->vtcr = 0;
/*
* Flush the init params from the data cache because the struct will
* be read while the MMU is off.
*/
kvm_flush_dcache_to_poc(params, sizeof(*params));
}
static void hyp_install_host_vector(void)
{
struct kvm_nvhe_init_params *params;
struct arm_smccc_res res;
/* Switch from the HYP stub to our own HYP init vector */
__hyp_set_vectors(kvm_get_idmap_vector());
/*
* Call initialization code, and switch to the full blown HYP code.
* If the cpucaps haven't been finalized yet, something has gone very
* wrong, and hyp will crash and burn when it uses any
* cpus_have_const_cap() wrapper.
*/
BUG_ON(!system_capabilities_finalized());
params = this_cpu_ptr_nvhe_sym(kvm_init_params);
arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__kvm_hyp_init), virt_to_phys(params), &res);
WARN_ON(res.a0 != SMCCC_RET_SUCCESS);
}
static void cpu_init_hyp_mode(void)
{
hyp_install_host_vector();
/*
* Disabling SSBD on a non-VHE system requires us to enable SSBS
* at EL2.
*/
if (this_cpu_has_cap(ARM64_SSBS) &&
arm64_get_spectre_v4_state() == SPECTRE_VULNERABLE) {
kvm_call_hyp_nvhe(__kvm_enable_ssbs);
}
}
static void cpu_hyp_reset(void)
{
if (!is_kernel_in_hyp_mode())
__hyp_reset_vectors();
}
/*
* EL2 vectors can be mapped and rerouted in a number of ways,
* depending on the kernel configuration and CPU present:
*
* - If the CPU is affected by Spectre-v2, the hardening sequence is
* placed in one of the vector slots, which is executed before jumping
* to the real vectors.
*
* - If the CPU also has the ARM64_SPECTRE_V3A cap, the slot
* containing the hardening sequence is mapped next to the idmap page,
* and executed before jumping to the real vectors.
*
* - If the CPU only has the ARM64_SPECTRE_V3A cap, then an
* empty slot is selected, mapped next to the idmap page, and
* executed before jumping to the real vectors.
*
* Note that ARM64_SPECTRE_V3A is somewhat incompatible with
* VHE, as we don't have hypervisor-specific mappings. If the system
* is VHE and yet selects this capability, it will be ignored.
*/
static void cpu_set_hyp_vector(void)
{
struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data);
void *vector = hyp_spectre_vector_selector[data->slot];
if (!is_protected_kvm_enabled())
*this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector;
else
kvm_call_hyp_nvhe(__pkvm_cpu_set_vector, data->slot);
}
static void cpu_hyp_init_context(void)
{
kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt);
if (!is_kernel_in_hyp_mode())
cpu_init_hyp_mode();
}
static void cpu_hyp_init_features(void)
{
cpu_set_hyp_vector();
kvm_arm_init_debug();
if (is_kernel_in_hyp_mode())
kvm_timer_init_vhe();
if (vgic_present)
kvm_vgic_init_cpu_hardware();
}
static void cpu_hyp_reinit(void)
{
cpu_hyp_reset();
cpu_hyp_init_context();
cpu_hyp_init_features();
}
static void _kvm_arch_hardware_enable(void *discard)
{
if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
cpu_hyp_reinit();
__this_cpu_write(kvm_arm_hardware_enabled, 1);
}
}
int kvm_arch_hardware_enable(void)
{
int was_enabled = __this_cpu_read(kvm_arm_hardware_enabled);
_kvm_arch_hardware_enable(NULL);
if (!was_enabled) {
kvm_vgic_cpu_up();
kvm_timer_cpu_up();
}
return 0;
}
static void _kvm_arch_hardware_disable(void *discard)
{
if (__this_cpu_read(kvm_arm_hardware_enabled)) {
cpu_hyp_reset();
__this_cpu_write(kvm_arm_hardware_enabled, 0);
}
}
void kvm_arch_hardware_disable(void)
{
if (__this_cpu_read(kvm_arm_hardware_enabled)) {
kvm_timer_cpu_down();
kvm_vgic_cpu_down();
}
if (!is_protected_kvm_enabled())
_kvm_arch_hardware_disable(NULL);
}
#ifdef CONFIG_CPU_PM
static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
unsigned long cmd,
void *v)
{
/*
* kvm_arm_hardware_enabled is left with its old value over
* PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
* re-enable hyp.
*/
switch (cmd) {
case CPU_PM_ENTER:
if (__this_cpu_read(kvm_arm_hardware_enabled))
/*
* don't update kvm_arm_hardware_enabled here
* so that the hardware will be re-enabled
* when we resume. See below.
*/
cpu_hyp_reset();
return NOTIFY_OK;
case CPU_PM_ENTER_FAILED:
case CPU_PM_EXIT:
if (__this_cpu_read(kvm_arm_hardware_enabled))
/* The hardware was enabled before suspend. */
cpu_hyp_reinit();
return NOTIFY_OK;
default:
return NOTIFY_DONE;
}
}
static struct notifier_block hyp_init_cpu_pm_nb = {
.notifier_call = hyp_init_cpu_pm_notifier,
};
static void __init hyp_cpu_pm_init(void)
{
if (!is_protected_kvm_enabled())
cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
}
static void __init hyp_cpu_pm_exit(void)
{
if (!is_protected_kvm_enabled())
cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
}
#else
static inline void __init hyp_cpu_pm_init(void)
{
}
static inline void __init hyp_cpu_pm_exit(void)
{
}
#endif
static void __init init_cpu_logical_map(void)
{
unsigned int cpu;
/*
* Copy the MPIDR <-> logical CPU ID mapping to hyp.
* Only copy the set of online CPUs whose features have been checked
* against the finalized system capabilities. The hypervisor will not
* allow any other CPUs from the `possible` set to boot.
*/
for_each_online_cpu(cpu)
hyp_cpu_logical_map[cpu] = cpu_logical_map(cpu);
}
#define init_psci_0_1_impl_state(config, what) \
config.psci_0_1_ ## what ## _implemented = psci_ops.what
static bool __init init_psci_relay(void)
{
/*
* If PSCI has not been initialized, protected KVM cannot install
* itself on newly booted CPUs.
*/
if (!psci_ops.get_version) {
kvm_err("Cannot initialize protected mode without PSCI\n");
return false;
}
kvm_host_psci_config.version = psci_ops.get_version();
if (kvm_host_psci_config.version == PSCI_VERSION(0, 1)) {
kvm_host_psci_config.function_ids_0_1 = get_psci_0_1_function_ids();
init_psci_0_1_impl_state(kvm_host_psci_config, cpu_suspend);
init_psci_0_1_impl_state(kvm_host_psci_config, cpu_on);
init_psci_0_1_impl_state(kvm_host_psci_config, cpu_off);
init_psci_0_1_impl_state(kvm_host_psci_config, migrate);
}
return true;
}
static int __init init_subsystems(void)
{
int err = 0;
/*
* Enable hardware so that subsystem initialisation can access EL2.
*/
on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);
/*
* Register CPU lower-power notifier
*/
hyp_cpu_pm_init();
/*
* Init HYP view of VGIC
*/
err = kvm_vgic_hyp_init();
switch (err) {
case 0:
vgic_present = true;
break;
case -ENODEV:
case -ENXIO:
vgic_present = false;
err = 0;
break;
default:
goto out;
}
/*
* Init HYP architected timer support
*/
err = kvm_timer_hyp_init(vgic_present);
if (err)
goto out;
kvm_register_perf_callbacks(NULL);
out:
if (err)
hyp_cpu_pm_exit();
if (err || !is_protected_kvm_enabled())
on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
return err;
}
static void __init teardown_subsystems(void)
{
kvm_unregister_perf_callbacks();
hyp_cpu_pm_exit();
}
static void __init teardown_hyp_mode(void)
{
int cpu;
free_hyp_pgds();
for_each_possible_cpu(cpu) {
free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
free_pages(kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu], nvhe_percpu_order());
}
}
static int __init do_pkvm_init(u32 hyp_va_bits)
{
void *per_cpu_base = kvm_ksym_ref(kvm_nvhe_sym(kvm_arm_hyp_percpu_base));
int ret;
preempt_disable();
cpu_hyp_init_context();
ret = kvm_call_hyp_nvhe(__pkvm_init, hyp_mem_base, hyp_mem_size,
num_possible_cpus(), kern_hyp_va(per_cpu_base),
hyp_va_bits);
cpu_hyp_init_features();
/*
* The stub hypercalls are now disabled, so set our local flag to
* prevent a later re-init attempt in kvm_arch_hardware_enable().
*/
__this_cpu_write(kvm_arm_hardware_enabled, 1);
preempt_enable();
return ret;
}
static u64 get_hyp_id_aa64pfr0_el1(void)
{
/*
* Track whether the system isn't affected by spectre/meltdown in the
* hypervisor's view of id_aa64pfr0_el1, used for protected VMs.
* Although this is per-CPU, we make it global for simplicity, e.g., not
* to have to worry about vcpu migration.
*
* Unlike for non-protected VMs, userspace cannot override this for
* protected VMs.
*/
u64 val = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
val &= ~(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2) |
ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3));
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV2),
arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED);
val |= FIELD_PREP(ARM64_FEATURE_MASK(ID_AA64PFR0_EL1_CSV3),
arm64_get_meltdown_state() == SPECTRE_UNAFFECTED);
return val;
}
static void kvm_hyp_init_symbols(void)
{
kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = get_hyp_id_aa64pfr0_el1();
kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1);
kvm_nvhe_sym(id_aa64isar0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR0_EL1);
kvm_nvhe_sym(id_aa64isar1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
kvm_nvhe_sym(id_aa64isar2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1);
kvm_nvhe_sym(id_aa64smfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64SMFR0_EL1);
kvm_nvhe_sym(__icache_flags) = __icache_flags;
kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits;
}
static int __init kvm_hyp_init_protection(u32 hyp_va_bits)
{
void *addr = phys_to_virt(hyp_mem_base);
int ret;
ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
if (ret)
return ret;
ret = do_pkvm_init(hyp_va_bits);
if (ret)
return ret;
free_hyp_pgds();
return 0;
}
/* Inits Hyp-mode on all online CPUs */
static int __init init_hyp_mode(void)
{
u32 hyp_va_bits;
int cpu;
int err = -ENOMEM;
/*
* The protected Hyp-mode cannot be initialized if the memory pool
* allocation has failed.
*/
if (is_protected_kvm_enabled() && !hyp_mem_base)
goto out_err;
/*
* Allocate Hyp PGD and setup Hyp identity mapping
*/
err = kvm_mmu_init(&hyp_va_bits);
if (err)
goto out_err;
/*
* Allocate stack pages for Hypervisor-mode
*/
for_each_possible_cpu(cpu) {
unsigned long stack_page;
stack_page = __get_free_page(GFP_KERNEL);
if (!stack_page) {
err = -ENOMEM;
goto out_err;
}
per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
}
/*
* Allocate and initialize pages for Hypervisor-mode percpu regions.
*/
for_each_possible_cpu(cpu) {
struct page *page;
void *page_addr;
page = alloc_pages(GFP_KERNEL, nvhe_percpu_order());
if (!page) {
err = -ENOMEM;
goto out_err;
}
page_addr = page_address(page);
memcpy(page_addr, CHOOSE_NVHE_SYM(__per_cpu_start), nvhe_percpu_size());
kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu] = (unsigned long)page_addr;
}
/*
* Map the Hyp-code called directly from the host
*/
err = create_hyp_mappings(kvm_ksym_ref(__hyp_text_start),
kvm_ksym_ref(__hyp_text_end), PAGE_HYP_EXEC);
if (err) {
kvm_err("Cannot map world-switch code\n");
goto out_err;
}
err = create_hyp_mappings(kvm_ksym_ref(__hyp_rodata_start),
kvm_ksym_ref(__hyp_rodata_end), PAGE_HYP_RO);
if (err) {
kvm_err("Cannot map .hyp.rodata section\n");
goto out_err;
}
err = create_hyp_mappings(kvm_ksym_ref(__start_rodata),
kvm_ksym_ref(__end_rodata), PAGE_HYP_RO);
if (err) {
kvm_err("Cannot map rodata section\n");
goto out_err;
}
/*
* .hyp.bss is guaranteed to be placed at the beginning of the .bss
* section thanks to an assertion in the linker script. Map it RW and
* the rest of .bss RO.
*/
err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_start),
kvm_ksym_ref(__hyp_bss_end), PAGE_HYP);
if (err) {
kvm_err("Cannot map hyp bss section: %d\n", err);
goto out_err;
}
err = create_hyp_mappings(kvm_ksym_ref(__hyp_bss_end),
kvm_ksym_ref(__bss_stop), PAGE_HYP_RO);
if (err) {
kvm_err("Cannot map bss section\n");
goto out_err;
}
/*
* Map the Hyp stack pages
*/
for_each_possible_cpu(cpu) {
struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
char *stack_page = (char *)per_cpu(kvm_arm_hyp_stack_page, cpu);
unsigned long hyp_addr;
/*
* Allocate a contiguous HYP private VA range for the stack
* and guard page. The allocation is also aligned based on
* the order of its size.
*/
err = hyp_alloc_private_va_range(PAGE_SIZE * 2, &hyp_addr);
if (err) {
kvm_err("Cannot allocate hyp stack guard page\n");
goto out_err;
}
/*
* Since the stack grows downwards, map the stack to the page
* at the higher address and leave the lower guard page
* unbacked.
*
* Any valid stack address now has the PAGE_SHIFT bit as 1
* and addresses corresponding to the guard page have the
* PAGE_SHIFT bit as 0 - this is used for overflow detection.
*/
err = __create_hyp_mappings(hyp_addr + PAGE_SIZE, PAGE_SIZE,
__pa(stack_page), PAGE_HYP);
if (err) {
kvm_err("Cannot map hyp stack\n");
goto out_err;
}
/*
* Save the stack PA in nvhe_init_params. This will be needed
* to recreate the stack mapping in protected nVHE mode.
* __hyp_pa() won't do the right thing there, since the stack
* has been mapped in the flexible private VA space.
*/
params->stack_pa = __pa(stack_page);
params->stack_hyp_va = hyp_addr + (2 * PAGE_SIZE);
}
for_each_possible_cpu(cpu) {
char *percpu_begin = (char *)kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];
char *percpu_end = percpu_begin + nvhe_percpu_size();
/* Map Hyp percpu pages */
err = create_hyp_mappings(percpu_begin, percpu_end, PAGE_HYP);
if (err) {
kvm_err("Cannot map hyp percpu region\n");
goto out_err;
}
/* Prepare the CPU initialization parameters */
cpu_prepare_hyp_mode(cpu, hyp_va_bits);
}
kvm_hyp_init_symbols();
if (is_protected_kvm_enabled()) {
init_cpu_logical_map();
if (!init_psci_relay()) {
err = -ENODEV;
goto out_err;
}
err = kvm_hyp_init_protection(hyp_va_bits);
if (err) {
kvm_err("Failed to init hyp memory protection\n");
goto out_err;
}
}
return 0;
out_err:
teardown_hyp_mode();
kvm_err("error initializing Hyp mode: %d\n", err);
return err;
}
static void __init _kvm_host_prot_finalize(void *arg)
{
int *err = arg;
if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)))
WRITE_ONCE(*err, -EINVAL);
}
static int __init pkvm_drop_host_privileges(void)
{
int ret = 0;
/*
* Flip the static key upfront as that may no longer be possible
* once the host stage 2 is installed.
*/
static_branch_enable(&kvm_protected_mode_initialized);
on_each_cpu(_kvm_host_prot_finalize, &ret, 1);
return ret;
}
static int __init finalize_hyp_mode(void)
{
if (!is_protected_kvm_enabled())
return 0;
/*
* Exclude HYP sections from kmemleak so that they don't get peeked
* at, which would end badly once inaccessible.
*/
kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start);
kmemleak_free_part_phys(hyp_mem_base, hyp_mem_size);
return pkvm_drop_host_privileges();
}
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
{
struct kvm_vcpu *vcpu;
unsigned long i;
mpidr &= MPIDR_HWID_BITMASK;
kvm_for_each_vcpu(i, vcpu, kvm) {
if (mpidr == kvm_vcpu_get_mpidr_aff(vcpu))
return vcpu;
}
return NULL;
}
bool kvm_arch_irqchip_in_kernel(struct kvm *kvm)
{
return irqchip_in_kernel(kvm);
}
bool kvm_arch_has_irq_bypass(void)
{
return true;
}
int kvm_arch_irq_bypass_add_producer(struct irq_bypass_consumer *cons,
struct irq_bypass_producer *prod)
{
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
return kvm_vgic_v4_set_forwarding(irqfd->kvm, prod->irq,
&irqfd->irq_entry);
}
void kvm_arch_irq_bypass_del_producer(struct irq_bypass_consumer *cons,
struct irq_bypass_producer *prod)
{
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
kvm_vgic_v4_unset_forwarding(irqfd->kvm, prod->irq,
&irqfd->irq_entry);
}
void kvm_arch_irq_bypass_stop(struct irq_bypass_consumer *cons)
{
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
kvm_arm_halt_guest(irqfd->kvm);
}
void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
{
struct kvm_kernel_irqfd *irqfd =
container_of(cons, struct kvm_kernel_irqfd, consumer);
kvm_arm_resume_guest(irqfd->kvm);
}
/* Initialize Hyp-mode and memory mappings on all CPUs */
static __init int kvm_arm_init(void)
{
int err;
bool in_hyp_mode;
if (!is_hyp_mode_available()) {
kvm_info("HYP mode not available\n");
return -ENODEV;
}
if (kvm_get_mode() == KVM_MODE_NONE) {
kvm_info("KVM disabled from command line\n");
return -ENODEV;
}
err = kvm_sys_reg_table_init();
if (err) {
kvm_info("Error initializing system register tables");
return err;
}
in_hyp_mode = is_kernel_in_hyp_mode();
if (cpus_have_final_cap(ARM64_WORKAROUND_DEVICE_LOAD_ACQUIRE) ||
cpus_have_final_cap(ARM64_WORKAROUND_1508412))
kvm_info("Guests without required CPU erratum workarounds can deadlock system!\n" \
"Only trusted guests should be used on this system.\n");
err = kvm_set_ipa_limit();
if (err)
return err;
err = kvm_arm_init_sve();
if (err)
return err;
err = kvm_arm_vmid_alloc_init();
if (err) {
kvm_err("Failed to initialize VMID allocator.\n");
return err;
}
if (!in_hyp_mode) {
err = init_hyp_mode();
if (err)
goto out_err;
}
err = kvm_init_vector_slots();
if (err) {
kvm_err("Cannot initialise vector slots\n");
goto out_hyp;
}
err = init_subsystems();
if (err)
goto out_hyp;
if (!in_hyp_mode) {
err = finalize_hyp_mode();
if (err) {
kvm_err("Failed to finalize Hyp protection\n");
goto out_subs;
}
}
if (is_protected_kvm_enabled()) {
kvm_info("Protected nVHE mode initialized successfully\n");
} else if (in_hyp_mode) {
kvm_info("VHE mode initialized successfully\n");
} else {
kvm_info("Hyp mode initialized successfully\n");
}
/*
* FIXME: Do something reasonable if kvm_init() fails after pKVM
* hypervisor protection is finalized.
*/
err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
if (err)
goto out_subs;
return 0;
out_subs:
teardown_subsystems();
out_hyp:
if (!in_hyp_mode)
teardown_hyp_mode();
out_err:
kvm_arm_vmid_alloc_free();
return err;
}
static int __init early_kvm_mode_cfg(char *arg)
{
if (!arg)
return -EINVAL;
if (strcmp(arg, "none") == 0) {
kvm_mode = KVM_MODE_NONE;
return 0;
}
if (!is_hyp_mode_available()) {
pr_warn_once("KVM is not available. Ignoring kvm-arm.mode\n");
return 0;
}
if (strcmp(arg, "protected") == 0) {
if (!is_kernel_in_hyp_mode())
kvm_mode = KVM_MODE_PROTECTED;
else
pr_warn_once("Protected KVM not available with VHE\n");
return 0;
}
if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode())) {
kvm_mode = KVM_MODE_DEFAULT;
return 0;
}
if (strcmp(arg, "nested") == 0 && !WARN_ON(!is_kernel_in_hyp_mode())) {
kvm_mode = KVM_MODE_NV;
return 0;
}
return -EINVAL;
}
early_param("kvm-arm.mode", early_kvm_mode_cfg);
enum kvm_mode kvm_get_mode(void)
{
return kvm_mode;
}
module_init(kvm_arm_init);