diff options
Diffstat (limited to 'arch/arm64/kvm/vgic/vgic-init.c')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic-init.c | 641 |
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; +} |