KVM: arm64: Move virt/kvm/arm to arch/arm64

Now that the 32bit KVM/arm host is a distant memory, let's move the
whole of the KVM/arm64 code into the arm64 tree.

As they said in the song: Welcome Home (Sanitarium).

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200513104034.74741-1-maz@kernel.org

1 files changed, 556 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 000000000000..32e32d67a127
--- /dev/null
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -0,0 +1,556 @@
+// 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)
+{
+	int i, ret;
+	struct kvm_vcpu *vcpu;
+
+	if (irqchip_in_kernel(kvm))
+		return -EEXIST;
+
+	/*
+	 * 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;
+
+	ret = -EBUSY;
+	if (!lock_all_vcpus(kvm))
+		return ret;
+
+	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->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:
+	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);
+	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->lock);
+		ret = vgic_register_redist_iodev(vcpu);
+		mutex_unlock(&vcpu->kvm->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.
+ * 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, idx;
+
+	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(i, vcpu, kvm)
+		kvm_vgic_vcpu_enable(vcpu);
+
+	ret = kvm_vgic_setup_default_irq_routing(kvm);
+	if (ret)
+		goto out;
+
+	vgic_debug_init(kvm);
+
+	dist->implementation_rev = 2;
+	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;
+
+	if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
+		list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) {
+			list_del(&rdreg->list);
+			kfree(rdreg);
+		}
+		INIT_LIST_HEAD(&dist->rd_regions);
+	}
+
+	if (vgic_has_its(kvm))
+		vgic_lpi_translation_cache_destroy(kvm);
+
+	if (vgic_supports_direct_msis(kvm))
+		vgic_v4_teardown(kvm);
+}
+
+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);
+}
+
+/* To be called with kvm->lock held */
+static void __kvm_vgic_destroy(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int i;
+
+	vgic_debug_destroy(kvm);
+
+	kvm_for_each_vcpu(i, vcpu, kvm)
+		kvm_vgic_vcpu_destroy(vcpu);
+
+	kvm_vgic_dist_destroy(kvm);
+}
+
+void kvm_vgic_destroy(struct kvm *kvm)
+{
+	mutex_lock(&kvm->lock);
+	__kvm_vgic_destroy(kvm);
+	mutex_unlock(&kvm->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->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);
+
+	if (ret)
+		__kvm_vgic_destroy(kvm);
+
+out:
+	mutex_unlock(&kvm->lock);
+	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;
+}
+
+/**
+ * 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)
+{
+	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);
+		if (!ret) {
+			static_branch_enable(&kvm_vgic_global_state.gicv3_cpuif);
+			kvm_info("GIC system register CPU interface enabled\n");
+		}
+		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 = 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;
+}