/*
* Copyright (C) 2015, 2016 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/kvm_host.h>
#include <kvm/arm_vgic.h>
#include <asm/kvm_mmu.h>
#include "vgic.h"
/*
* Initialization rules: there are multiple stages to the vgic
* initialization, both for the distributor and the CPU interfaces. The basic
* idea is that even though the VGIC is not functional or not requested from
* user space, the critical path of the run loop can still call VGIC functions
* that just won't do anything, without them having to check additional
* initialization flags to ensure they don't look at uninitialized data
* structures.
*
* Distributor:
*
* - kvm_vgic_early_init(): initialization of static data that doesn't
* depend on any sizing information or emulation type. No allocation
* is allowed there.
*
* - vgic_init(): allocation and initialization of the generic data
* structures that depend on sizing information (number of CPUs,
* number of interrupts). Also initializes the vcpu specific data
* structures. Can be executed lazily for GICv2.
*
* CPU Interface:
*
* - kvm_vgic_vcpu_init(): initialization of static data that
* doesn't depend on any sizing information or emulation type. No
* allocation is allowed there.
*/
/* EARLY INIT */
/**
* kvm_vgic_early_init() - Initialize static VGIC VCPU data structures
* @kvm: The VM whose VGIC districutor should be initialized
*
* Only do initialization of static structures that don't require any
* allocation or sizing information from userspace. vgic_init() called
* kvm_vgic_dist_init() which takes care of the rest.
*/
void kvm_vgic_early_init(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
INIT_LIST_HEAD(&dist->lpi_list_head);
raw_spin_lock_init(&dist->lpi_list_lock);
}
/* CREATION */
/**
* kvm_vgic_create: triggered by the instantiation of the VGIC device by
* user space, either through the legacy KVM_CREATE_IRQCHIP ioctl (v2 only)
* or through the generic KVM_CREATE_DEVICE API ioctl.
* irqchip_in_kernel() tells you if this function succeeded or not.
* @kvm: kvm struct pointer
* @type: KVM_DEV_TYPE_ARM_VGIC_V[23]
*/
int kvm_vgic_create(struct kvm *kvm, u32 type)
{
int i, vcpu_lock_idx = -1, ret;
struct kvm_vcpu *vcpu;
if (irqchip_in_kernel(kvm))
return -EEXIST;
/*
* This function is also called by the KVM_CREATE_IRQCHIP handler,
* which had no chance yet to check the availability of the GICv2
* emulation. So check this here again. KVM_CREATE_DEVICE does
* the proper checks already.
*/
if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
!kvm_vgic_global_state.can_emulate_gicv2)
return -ENODEV;
/*
* Any time a vcpu is run, vcpu_load is called which tries to grab the
* vcpu->mutex. By grabbing the vcpu->mutex of all VCPUs we ensure
* that no other VCPUs are run while we create the vgic.
*/
ret = -EBUSY;
kvm_for_each_vcpu(i, vcpu, kvm) {
if (!mutex_trylock(&vcpu->mutex))
goto out_unlock;
vcpu_lock_idx = i;
}
kvm_for_each_vcpu(i, vcpu, kvm) {
if (vcpu->arch.has_run_once)
goto out_unlock;
}
ret = 0;
if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
kvm->arch.max_vcpus = VGIC_V2_MAX_CPUS;
else
kvm->arch.max_vcpus = VGIC_V3_MAX_CPUS;
if (atomic_read(&kvm->online_vcpus) > kvm->arch.max_vcpus) {
ret = -E2BIG;
goto out_unlock;
}
kvm->arch.vgic.in_kernel = true;
kvm->arch.vgic.vgic_model = type;
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
else
INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
out_unlock:
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
mutex_unlock(&vcpu->mutex);
}
return ret;
}
/* INIT/DESTROY */
/**
* kvm_vgic_dist_init: initialize the dist data structures
* @kvm: kvm struct pointer
* @nr_spis: number of spis, frozen by caller
*/
static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
{
struct vgic_dist *dist = &kvm->arch.vgic;
struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
int i;
dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
if (!dist->spis)
return -ENOMEM;
/*
* In the following code we do not take the irq struct lock since
* no other action on irq structs can happen while the VGIC is
* not initialized yet:
* If someone wants to inject an interrupt or does a MMIO access, we
* require prior initialization in case of a virtual GICv3 or trigger
* initialization when using a virtual GICv2.
*/
for (i = 0; i < nr_spis; i++) {
struct vgic_irq *irq = &dist->spis[i];
irq->intid = i + VGIC_NR_PRIVATE_IRQS;
INIT_LIST_HEAD(&irq->ap_list);
raw_spin_lock_init(&irq->irq_lock);
irq->vcpu = NULL;
irq->target_vcpu = vcpu0;
kref_init(&irq->refcount);
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
irq->targets = 0;
irq->group = 0;
} else {
irq->mpidr = 0;
irq->group = 1;
}
}
return 0;
}
/**
* kvm_vgic_vcpu_init() - Initialize static VGIC VCPU data
* structures and register VCPU-specific KVM iodevs
*
* @vcpu: pointer to the VCPU being created and initialized
*
* Only do initialization, but do not actually enable the
* VGIC CPU interface
*/
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
int ret = 0;
int i;
vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
vgic_cpu->sgi_iodev.base_addr = VGIC_ADDR_UNDEF;
INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
raw_spin_lock_init(&vgic_cpu->ap_list_lock);
/*
* Enable and configure all SGIs to be edge-triggered and
* configure all PPIs as level-triggered.
*/
for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
INIT_LIST_HEAD(&irq->ap_list);
raw_spin_lock_init(&irq->irq_lock);
irq->intid = i;
irq->vcpu = NULL;
irq->target_vcpu = vcpu;
irq->targets = 1U << vcpu->vcpu_id;
kref_init(&irq->refcount);
if (vgic_irq_is_sgi(i)) {
/* SGIs */
irq->enabled = 1;
irq->config = VGIC_CONFIG_EDGE;
} else {
/* PPIs */
irq->config = VGIC_CONFIG_LEVEL;
}
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
irq->group = 1;
else
irq->group = 0;
}
if (!irqchip_in_kernel(vcpu->kvm))
return 0;
/*
* If we are creating a VCPU with a GICv3 we must also register the
* KVM io device for the redistributor that belongs to this VCPU.
*/
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
mutex_lock(&vcpu->kvm->lock);
ret = vgic_register_redist_iodev(vcpu);
mutex_unlock(&vcpu->kvm->lock);
}
return ret;
}
static void kvm_vgic_vcpu_enable(struct kvm_vcpu *vcpu)
{
if (kvm_vgic_global_state.type == VGIC_V2)
vgic_v2_enable(vcpu);
else
vgic_v3_enable(vcpu);
}
/*
* vgic_init: allocates and initializes dist and vcpu data structures
* depending on two dimensioning parameters:
* - the number of spis
* - the number of vcpus
* The function is generally called when nr_spis has been explicitly set
* by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
* vgic_initialized() returns true when this function has succeeded.
* Must be called with kvm->lock held!
*/
int vgic_init(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
struct kvm_vcpu *vcpu;
int ret = 0, i, idx;
if (vgic_initialized(kvm))
return 0;
/* Are we also in the middle of creating a VCPU? */
if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
return -EBUSY;
/* freeze the number of spis */
if (!dist->nr_spis)
dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
if (ret)
goto out;
/* Initialize groups on CPUs created before the VGIC type was known */
kvm_for_each_vcpu(idx, vcpu, kvm) {
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3)
irq->group = 1;
else
irq->group = 0;
}
}
if (vgic_has_its(kvm)) {
ret = vgic_v4_init(kvm);
if (ret)
goto out;
}
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_vgic_vcpu_enable(vcpu);
ret = kvm_vgic_setup_default_irq_routing(kvm);
if (ret)
goto out;
vgic_debug_init(kvm);
dist->implementation_rev = 2;
dist->initialized = true;
out:
return ret;
}
static void kvm_vgic_dist_destroy(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
struct vgic_redist_region *rdreg, *next;
dist->ready = false;
dist->initialized = false;
kfree(dist->spis);
dist->spis = NULL;
dist->nr_spis = 0;
if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) {
list_del(&rdreg->list);
kfree(rdreg);
}
INIT_LIST_HEAD(&dist->rd_regions);
}
if (vgic_supports_direct_msis(kvm))
vgic_v4_teardown(kvm);
}
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
{
struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
}
/* To be called with kvm->lock held */
static void __kvm_vgic_destroy(struct kvm *kvm)
{
struct kvm_vcpu *vcpu;
int i;
vgic_debug_destroy(kvm);
kvm_vgic_dist_destroy(kvm);
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_vgic_vcpu_destroy(vcpu);
}
void kvm_vgic_destroy(struct kvm *kvm)
{
mutex_lock(&kvm->lock);
__kvm_vgic_destroy(kvm);
mutex_unlock(&kvm->lock);
}
/**
* vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
* is a GICv2. A GICv3 must be explicitly initialized by the guest using the
* KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group.
* @kvm: kvm struct pointer
*/
int vgic_lazy_init(struct kvm *kvm)
{
int ret = 0;
if (unlikely(!vgic_initialized(kvm))) {
/*
* We only provide the automatic initialization of the VGIC
* for the legacy case of a GICv2. Any other type must
* be explicitly initialized once setup with the respective
* KVM device call.
*/
if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
return -EBUSY;
mutex_lock(&kvm->lock);
ret = vgic_init(kvm);
mutex_unlock(&kvm->lock);
}
return ret;
}
/* RESOURCE MAPPING */
/**
* Map the MMIO regions depending on the VGIC model exposed to the guest
* called on the first VCPU run.
* Also map the virtual CPU interface into the VM.
* v2/v3 derivatives call vgic_init if not already done.
* vgic_ready() returns true if this function has succeeded.
* @kvm: kvm struct pointer
*/
int kvm_vgic_map_resources(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
int ret = 0;
mutex_lock(&kvm->lock);
if (!irqchip_in_kernel(kvm))
goto out;
if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
ret = vgic_v2_map_resources(kvm);
else
ret = vgic_v3_map_resources(kvm);
if (ret)
__kvm_vgic_destroy(kvm);
out:
mutex_unlock(&kvm->lock);
return ret;
}
/* GENERIC PROBE */
static int vgic_init_cpu_starting(unsigned int cpu)
{
enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
return 0;
}
static int vgic_init_cpu_dying(unsigned int cpu)
{
disable_percpu_irq(kvm_vgic_global_state.maint_irq);
return 0;
}
static irqreturn_t vgic_maintenance_handler(int irq, void *data)
{
/*
* We cannot rely on the vgic maintenance interrupt to be
* delivered synchronously. This means we can only use it to
* exit the VM, and we perform the handling of EOIed
* interrupts on the exit path (see vgic_fold_lr_state).
*/
return IRQ_HANDLED;
}
/**
* kvm_vgic_init_cpu_hardware - initialize the GIC VE hardware
*
* For a specific CPU, initialize the GIC VE hardware.
*/
void kvm_vgic_init_cpu_hardware(void)
{
BUG_ON(preemptible());
/*
* We want to make sure the list registers start out clear so that we
* only have the program the used registers.
*/
if (kvm_vgic_global_state.type == VGIC_V2)
vgic_v2_init_lrs();
else
kvm_call_hyp(__vgic_v3_init_lrs);
}
/**
* kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
* according to the host GIC model. Accordingly calls either
* vgic_v2/v3_probe which registers the KVM_DEVICE that can be
* instantiated by a guest later on .
*/
int kvm_vgic_hyp_init(void)
{
const struct gic_kvm_info *gic_kvm_info;
int ret;
gic_kvm_info = gic_get_kvm_info();
if (!gic_kvm_info)
return -ENODEV;
if (!gic_kvm_info->maint_irq) {
kvm_err("No vgic maintenance irq\n");
return -ENXIO;
}
switch (gic_kvm_info->type) {
case GIC_V2:
ret = vgic_v2_probe(gic_kvm_info);
break;
case GIC_V3:
ret = vgic_v3_probe(gic_kvm_info);
if (!ret) {
static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
kvm_info("GIC system register CPU interface enabled\n");
}
break;
default:
ret = -ENODEV;
};
if (ret)
return ret;
kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
vgic_maintenance_handler,
"vgic", kvm_get_running_vcpus());
if (ret) {
kvm_err("Cannot register interrupt %d\n",
kvm_vgic_global_state.maint_irq);
return ret;
}
ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
"kvm/arm/vgic:starting",
vgic_init_cpu_starting, vgic_init_cpu_dying);
if (ret) {
kvm_err("Cannot register vgic CPU notifier\n");
goto out_free_irq;
}
kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
return 0;
out_free_irq:
free_percpu_irq(kvm_vgic_global_state.maint_irq,
kvm_get_running_vcpus());
return ret;
}
