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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm64/kvm/vgic/vgic-init.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm64/kvm/vgic/vgic-init.c')
-rw-r--r--arch/arm64/kvm/vgic/vgic-init.c641
1 files changed, 641 insertions, 0 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
new file mode 100644
index 000000000..0919e3b8f
--- /dev/null
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2015, 2016 ARM Ltd.
+ */
+
+#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_emulate.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);
+ INIT_LIST_HEAD(&dist->lpi_translation_cache);
+ 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)
+{
+ struct kvm_vcpu *vcpu;
+ unsigned long i;
+ int ret;
+
+ /*
+ * 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;
+
+ /* Must be held to avoid race with vCPU creation */
+ lockdep_assert_held(&kvm->lock);
+
+ ret = -EBUSY;
+ if (!lock_all_vcpus(kvm))
+ return ret;
+
+ mutex_lock(&kvm->arch.config_lock);
+
+ if (irqchip_in_kernel(kvm)) {
+ ret = -EEXIST;
+ goto out_unlock;
+ }
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ if (vcpu_has_run_once(vcpu))
+ goto out_unlock;
+ }
+ ret = 0;
+
+ if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
+ kvm->max_vcpus = VGIC_V2_MAX_CPUS;
+ else
+ kvm->max_vcpus = VGIC_V3_MAX_CPUS;
+
+ if (atomic_read(&kvm->online_vcpus) > kvm->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:
+ mutex_unlock(&kvm->arch.config_lock);
+ unlock_all_vcpus(kvm);
+ 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_ACCOUNT);
+ 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);
+ switch (dist->vgic_model) {
+ case KVM_DEV_TYPE_ARM_VGIC_V2:
+ irq->targets = 0;
+ irq->group = 0;
+ break;
+ case KVM_DEV_TYPE_ARM_VGIC_V3:
+ irq->mpidr = 0;
+ irq->group = 1;
+ break;
+ default:
+ kfree(dist->spis);
+ dist->spis = NULL;
+ return -EINVAL;
+ }
+ }
+ 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;
+
+ INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
+ raw_spin_lock_init(&vgic_cpu->ap_list_lock);
+ atomic_set(&vgic_cpu->vgic_v3.its_vpe.vlpi_count, 0);
+
+ /*
+ * 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;
+ 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 (!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->slots_lock);
+ ret = vgic_register_redist_iodev(vcpu);
+ mutex_unlock(&vcpu->kvm->slots_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.
+ */
+int vgic_init(struct kvm *kvm)
+{
+ struct vgic_dist *dist = &kvm->arch.vgic;
+ struct kvm_vcpu *vcpu;
+ int ret = 0, i;
+ unsigned long idx;
+
+ lockdep_assert_held(&kvm->arch.config_lock);
+
+ 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];
+ switch (dist->vgic_model) {
+ case KVM_DEV_TYPE_ARM_VGIC_V3:
+ irq->group = 1;
+ irq->mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+ break;
+ case KVM_DEV_TYPE_ARM_VGIC_V2:
+ irq->group = 0;
+ irq->targets = 1U << idx;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ }
+
+ if (vgic_has_its(kvm))
+ vgic_lpi_translation_cache_init(kvm);
+
+ /*
+ * If we have GICv4.1 enabled, unconditionnaly request enable the
+ * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
+ * enable it if we present a virtual ITS to the guest.
+ */
+ if (vgic_supports_direct_msis(kvm)) {
+ ret = vgic_v4_init(kvm);
+ if (ret)
+ goto out;
+ }
+
+ kvm_for_each_vcpu(idx, vcpu, kvm)
+ kvm_vgic_vcpu_enable(vcpu);
+
+ ret = kvm_vgic_setup_default_irq_routing(kvm);
+ if (ret)
+ goto out;
+
+ vgic_debug_init(kvm);
+
+ /*
+ * If userspace didn't set the GIC implementation revision,
+ * default to the latest and greatest. You know want it.
+ */
+ if (!dist->implementation_rev)
+ dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
+ 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;
+ dist->vgic_dist_base = VGIC_ADDR_UNDEF;
+
+ if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
+ list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list)
+ vgic_v3_free_redist_region(rdreg);
+ INIT_LIST_HEAD(&dist->rd_regions);
+ } else {
+ dist->vgic_cpu_base = VGIC_ADDR_UNDEF;
+ }
+
+ if (vgic_has_its(kvm))
+ vgic_lpi_translation_cache_destroy(kvm);
+
+ if (vgic_supports_direct_msis(kvm))
+ vgic_v4_teardown(kvm);
+}
+
+static void __kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+ /*
+ * Retire all pending LPIs on this vcpu anyway as we're
+ * going to destroy it.
+ */
+ vgic_flush_pending_lpis(vcpu);
+
+ INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
+ if (vcpu->kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
+ vgic_unregister_redist_iodev(vcpu);
+ vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF;
+ }
+}
+
+void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = vcpu->kvm;
+
+ mutex_lock(&kvm->slots_lock);
+ __kvm_vgic_vcpu_destroy(vcpu);
+ mutex_unlock(&kvm->slots_lock);
+}
+
+void kvm_vgic_destroy(struct kvm *kvm)
+{
+ struct kvm_vcpu *vcpu;
+ unsigned long i;
+
+ mutex_lock(&kvm->slots_lock);
+
+ vgic_debug_destroy(kvm);
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ __kvm_vgic_vcpu_destroy(vcpu);
+
+ mutex_lock(&kvm->arch.config_lock);
+
+ kvm_vgic_dist_destroy(kvm);
+
+ mutex_unlock(&kvm->arch.config_lock);
+ mutex_unlock(&kvm->slots_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->arch.config_lock);
+ ret = vgic_init(kvm);
+ mutex_unlock(&kvm->arch.config_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 calls vgic_init() if not already done.
+ * v3 and derivatives return an error if the VGIC is not initialized.
+ * 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;
+ enum vgic_type type;
+ gpa_t dist_base;
+ int ret = 0;
+
+ if (likely(vgic_ready(kvm)))
+ return 0;
+
+ mutex_lock(&kvm->slots_lock);
+ mutex_lock(&kvm->arch.config_lock);
+ if (vgic_ready(kvm))
+ goto out;
+
+ if (!irqchip_in_kernel(kvm))
+ goto out;
+
+ if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2) {
+ ret = vgic_v2_map_resources(kvm);
+ type = VGIC_V2;
+ } else {
+ ret = vgic_v3_map_resources(kvm);
+ type = VGIC_V3;
+ }
+
+ if (ret)
+ goto out;
+
+ dist->ready = true;
+ dist_base = dist->vgic_dist_base;
+ mutex_unlock(&kvm->arch.config_lock);
+
+ ret = vgic_register_dist_iodev(kvm, dist_base, type);
+ if (ret)
+ kvm_err("Unable to register VGIC dist MMIO regions\n");
+
+ goto out_slots;
+out:
+ mutex_unlock(&kvm->arch.config_lock);
+out_slots:
+ mutex_unlock(&kvm->slots_lock);
+
+ if (ret)
+ kvm_vgic_destroy(kvm);
+
+ 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;
+}
+
+static struct gic_kvm_info *gic_kvm_info;
+
+void __init vgic_set_kvm_info(const struct gic_kvm_info *info)
+{
+ BUG_ON(gic_kvm_info != NULL);
+ gic_kvm_info = kmalloc(sizeof(*info), GFP_KERNEL);
+ if (gic_kvm_info)
+ *gic_kvm_info = *info;
+}
+
+/**
+ * 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)
+{
+ bool has_mask;
+ int ret;
+
+ if (!gic_kvm_info)
+ return -ENODEV;
+
+ has_mask = !gic_kvm_info->no_maint_irq_mask;
+
+ if (has_mask && !gic_kvm_info->maint_irq) {
+ kvm_err("No vgic maintenance irq\n");
+ return -ENXIO;
+ }
+
+ /*
+ * If we get one of these oddball non-GICs, taint the kernel,
+ * as we have no idea of how they *really* behave.
+ */
+ if (gic_kvm_info->no_hw_deactivation) {
+ kvm_info("Non-architectural vgic, tainting kernel\n");
+ add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
+ kvm_vgic_global_state.no_hw_deactivation = true;
+ }
+
+ 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;
+ }
+
+ kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
+
+ kfree(gic_kvm_info);
+ gic_kvm_info = NULL;
+
+ if (ret)
+ return ret;
+
+ if (!has_mask)
+ return 0;
+
+ 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;
+}