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/*
* 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"
/* 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.
*/
int kvm_vgic_create(struct kvm *kvm, u32 type)
{
int i, vcpu_lock_idx = -1, ret;
struct kvm_vcpu *vcpu;
mutex_lock(&kvm->lock);
if (irqchip_in_kernel(kvm)) {
ret = -EEXIST;
goto out;
}
/*
* 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) {
ret = -ENODEV;
goto out;
}
/*
* 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_vgic_global_state.vctrl_base is set on vgic probe (kvm_arch_init)
* it is stored in distributor struct for asm save/restore purpose
*/
kvm->arch.vgic.vctrl_base = kvm_vgic_global_state.vctrl_base;
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
out_unlock:
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
mutex_unlock(&vcpu->mutex);
}
out:
mutex_unlock(&kvm->lock);
return ret;
}
/* GENERIC PROBE */
static void vgic_init_maintenance_interrupt(void *info)
{
enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
}
static int vgic_cpu_notify(struct notifier_block *self,
unsigned long action, void *cpu)
{
switch (action) {
case CPU_STARTING:
case CPU_STARTING_FROZEN:
vgic_init_maintenance_interrupt(NULL);
break;
case CPU_DYING:
case CPU_DYING_FROZEN:
disable_percpu_irq(kvm_vgic_global_state.maint_irq);
break;
}
return NOTIFY_OK;
}
static struct notifier_block vgic_cpu_nb = {
.notifier_call = vgic_cpu_notify,
};
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_process_maintenance).
*/
return IRQ_HANDLED;
}
/**
* 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);
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 = __register_cpu_notifier(&vgic_cpu_nb);
if (ret) {
kvm_err("Cannot register vgic CPU notifier\n");
goto out_free_irq;
}
on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
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;
}
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