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-rw-r--r--virt/kvm/arm/vgic/vgic-init.c452
1 files changed, 452 insertions, 0 deletions
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
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index 000000000000..a1442f7c9c4d
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+++ b/virt/kvm/arm/vgic/vgic-init.c
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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"
+
+/*
+ * Initialization rules: there are multiple stages to the vgic
+ * initialization, both for the distributor and the CPU interfaces.
+ *
+ * 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_cpu_early_init(): initialization of static data that
+ * doesn't depend on any sizing information or emulation type. No
+ * allocation is allowed there.
+ */
+
+/* EARLY INIT */
+
+/*
+ * Those 2 functions should not be needed anymore but they
+ * still are called from arm.c
+ */
+void kvm_vgic_early_init(struct kvm *kvm)
+{
+}
+
+void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
+{
+}
+
+/* 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;
+
+ 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;
+}
+
+/* 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);
+ spin_lock_init(&irq->irq_lock);
+ irq->vcpu = NULL;
+ irq->target_vcpu = vcpu0;
+ if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
+ irq->targets = 0;
+ else
+ irq->mpidr = 0;
+ }
+ return 0;
+}
+
+/**
+ * kvm_vgic_vcpu_init: initialize the vcpu data structures and
+ * enable the VCPU interface
+ * @vcpu: the VCPU which's VGIC should be initialized
+ */
+static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ int i;
+
+ INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
+ 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);
+ spin_lock_init(&irq->irq_lock);
+ irq->intid = i;
+ irq->vcpu = NULL;
+ irq->target_vcpu = vcpu;
+ irq->targets = 1U << vcpu->vcpu_id;
+ if (vgic_irq_is_sgi(i)) {
+ /* SGIs */
+ irq->enabled = 1;
+ irq->config = VGIC_CONFIG_EDGE;
+ } else {
+ /* PPIs */
+ irq->config = VGIC_CONFIG_LEVEL;
+ }
+ }
+ 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;
+
+ if (vgic_initialized(kvm))
+ return 0;
+
+ /* 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;
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_vgic_vcpu_init(vcpu);
+
+ dist->initialized = true;
+out:
+ return ret;
+}
+
+static void kvm_vgic_dist_destroy(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+
+ mutex_lock(&kvm->lock);
+
+ dist->ready = false;
+ dist->initialized = false;
+
+ kfree(dist->spis);
+ kfree(dist->redist_iodevs);
+ dist->nr_spis = 0;
+
+ mutex_unlock(&kvm->lock);
+}
+
+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);
+}
+
+void kvm_vgic_destroy(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ int i;
+
+ kvm_vgic_dist_destroy(kvm);
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ kvm_vgic_vcpu_destroy(vcpu);
+}
+
+/**
+ * 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);
+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;
+}