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alistair23-linux/virt/kvm/arm/vgic/vgic-init.c

124 lines
3.0 KiB
C

/*
* 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"
/* 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;
}