diff options
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-v4.c')
| -rw-r--r-- | virt/kvm/arm/vgic/vgic-v4.c | 453 |
1 files changed, 0 insertions, 453 deletions
diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c deleted file mode 100644 index 27ac833e5ec7..000000000000 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ /dev/null @@ -1,453 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 2017 ARM Ltd. - * Author: Marc Zyngier <marc.zyngier@arm.com> - */ - -#include <linux/interrupt.h> -#include <linux/irq.h> -#include <linux/irqdomain.h> -#include <linux/kvm_host.h> -#include <linux/irqchip/arm-gic-v3.h> - -#include "vgic.h" - -/* - * How KVM uses GICv4 (insert rude comments here): - * - * The vgic-v4 layer acts as a bridge between several entities: - * - The GICv4 ITS representation offered by the ITS driver - * - VFIO, which is in charge of the PCI endpoint - * - The virtual ITS, which is the only thing the guest sees - * - * The configuration of VLPIs is triggered by a callback from VFIO, - * instructing KVM that a PCI device has been configured to deliver - * MSIs to a vITS. - * - * kvm_vgic_v4_set_forwarding() is thus called with the routing entry, - * and this is used to find the corresponding vITS data structures - * (ITS instance, device, event and irq) using a process that is - * extremely similar to the injection of an MSI. - * - * At this stage, we can link the guest's view of an LPI (uniquely - * identified by the routing entry) and the host irq, using the GICv4 - * driver mapping operation. Should the mapping succeed, we've then - * successfully upgraded the guest's LPI to a VLPI. We can then start - * with updating GICv4's view of the property table and generating an - * INValidation in order to kickstart the delivery of this VLPI to the - * guest directly, without software intervention. Well, almost. - * - * When the PCI endpoint is deconfigured, this operation is reversed - * with VFIO calling kvm_vgic_v4_unset_forwarding(). - * - * Once the VLPI has been mapped, it needs to follow any change the - * guest performs on its LPI through the vITS. For that, a number of - * command handlers have hooks to communicate these changes to the HW: - * - Any invalidation triggers a call to its_prop_update_vlpi() - * - The INT command results in a irq_set_irqchip_state(), which - * generates an INT on the corresponding VLPI. - * - The CLEAR command results in a irq_set_irqchip_state(), which - * generates an CLEAR on the corresponding VLPI. - * - DISCARD translates into an unmap, similar to a call to - * kvm_vgic_v4_unset_forwarding(). - * - MOVI is translated by an update of the existing mapping, changing - * the target vcpu, resulting in a VMOVI being generated. - * - MOVALL is translated by a string of mapping updates (similar to - * the handling of MOVI). MOVALL is horrible. - * - * Note that a DISCARD/MAPTI sequence emitted from the guest without - * reprogramming the PCI endpoint after MAPTI does not result in a - * VLPI being mapped, as there is no callback from VFIO (the guest - * will get the interrupt via the normal SW injection). Fixing this is - * not trivial, and requires some horrible messing with the VFIO - * internals. Not fun. Don't do that. - * - * Then there is the scheduling. Each time a vcpu is about to run on a - * physical CPU, KVM must tell the corresponding redistributor about - * it. And if we've migrated our vcpu from one CPU to another, we must - * tell the ITS (so that the messages reach the right redistributor). - * This is done in two steps: first issue a irq_set_affinity() on the - * irq corresponding to the vcpu, then call its_make_vpe_resident(). - * You must be in a non-preemptible context. On exit, a call to - * its_make_vpe_non_resident() tells the redistributor that we're done - * with the vcpu. - * - * Finally, the doorbell handling: Each vcpu is allocated an interrupt - * which will fire each time a VLPI is made pending whilst the vcpu is - * not running. Each time the vcpu gets blocked, the doorbell - * interrupt gets enabled. When the vcpu is unblocked (for whatever - * reason), the doorbell interrupt is disabled. - */ - -#define DB_IRQ_FLAGS (IRQ_NOAUTOEN | IRQ_DISABLE_UNLAZY | IRQ_NO_BALANCING) - -static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info) -{ - struct kvm_vcpu *vcpu = info; - - /* We got the message, no need to fire again */ - if (!kvm_vgic_global_state.has_gicv4_1 && - !irqd_irq_disabled(&irq_to_desc(irq)->irq_data)) - disable_irq_nosync(irq); - - vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true; - kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); - kvm_vcpu_kick(vcpu); - - return IRQ_HANDLED; -} - -static void vgic_v4_sync_sgi_config(struct its_vpe *vpe, struct vgic_irq *irq) -{ - vpe->sgi_config[irq->intid].enabled = irq->enabled; - vpe->sgi_config[irq->intid].group = irq->group; - vpe->sgi_config[irq->intid].priority = irq->priority; -} - -static void vgic_v4_enable_vsgis(struct kvm_vcpu *vcpu) -{ - struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; - int i; - - /* - * With GICv4.1, every virtual SGI can be directly injected. So - * let's pretend that they are HW interrupts, tied to a host - * IRQ. The SGI code will do its magic. - */ - for (i = 0; i < VGIC_NR_SGIS; i++) { - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); - struct irq_desc *desc; - unsigned long flags; - int ret; - - raw_spin_lock_irqsave(&irq->irq_lock, flags); - - if (irq->hw) - goto unlock; - - irq->hw = true; - irq->host_irq = irq_find_mapping(vpe->sgi_domain, i); - - /* Transfer the full irq state to the vPE */ - vgic_v4_sync_sgi_config(vpe, irq); - desc = irq_to_desc(irq->host_irq); - ret = irq_domain_activate_irq(irq_desc_get_irq_data(desc), - false); - if (!WARN_ON(ret)) { - /* Transfer pending state */ - ret = irq_set_irqchip_state(irq->host_irq, - IRQCHIP_STATE_PENDING, - irq->pending_latch); - WARN_ON(ret); - irq->pending_latch = false; - } - unlock: - raw_spin_unlock_irqrestore(&irq->irq_lock, flags); - vgic_put_irq(vcpu->kvm, irq); - } -} - -static void vgic_v4_disable_vsgis(struct kvm_vcpu *vcpu) -{ - int i; - - for (i = 0; i < VGIC_NR_SGIS; i++) { - struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, i); - struct irq_desc *desc; - unsigned long flags; - int ret; - - raw_spin_lock_irqsave(&irq->irq_lock, flags); - - if (!irq->hw) - goto unlock; - - irq->hw = false; - ret = irq_get_irqchip_state(irq->host_irq, - IRQCHIP_STATE_PENDING, - &irq->pending_latch); - WARN_ON(ret); - - desc = irq_to_desc(irq->host_irq); - irq_domain_deactivate_irq(irq_desc_get_irq_data(desc)); - unlock: - raw_spin_unlock_irqrestore(&irq->irq_lock, flags); - vgic_put_irq(vcpu->kvm, irq); - } -} - -/* Must be called with the kvm lock held */ -void vgic_v4_configure_vsgis(struct kvm *kvm) -{ - struct vgic_dist *dist = &kvm->arch.vgic; - struct kvm_vcpu *vcpu; - int i; - - kvm_arm_halt_guest(kvm); - - kvm_for_each_vcpu(i, vcpu, kvm) { - if (dist->nassgireq) - vgic_v4_enable_vsgis(vcpu); - else - vgic_v4_disable_vsgis(vcpu); - } - - kvm_arm_resume_guest(kvm); -} - -/** - * vgic_v4_init - Initialize the GICv4 data structures - * @kvm: Pointer to the VM being initialized - * - * We may be called each time a vITS is created, or when the - * vgic is initialized. This relies on kvm->lock to be - * held. In both cases, the number of vcpus should now be - * fixed. - */ -int vgic_v4_init(struct kvm *kvm) -{ - struct vgic_dist *dist = &kvm->arch.vgic; - struct kvm_vcpu *vcpu; - int i, nr_vcpus, ret; - - if (!kvm_vgic_global_state.has_gicv4) - return 0; /* Nothing to see here... move along. */ - - if (dist->its_vm.vpes) - return 0; - - nr_vcpus = atomic_read(&kvm->online_vcpus); - - dist->its_vm.vpes = kcalloc(nr_vcpus, sizeof(*dist->its_vm.vpes), - GFP_KERNEL); - if (!dist->its_vm.vpes) - return -ENOMEM; - - dist->its_vm.nr_vpes = nr_vcpus; - - kvm_for_each_vcpu(i, vcpu, kvm) - dist->its_vm.vpes[i] = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; - - ret = its_alloc_vcpu_irqs(&dist->its_vm); - if (ret < 0) { - kvm_err("VPE IRQ allocation failure\n"); - kfree(dist->its_vm.vpes); - dist->its_vm.nr_vpes = 0; - dist->its_vm.vpes = NULL; - return ret; - } - - kvm_for_each_vcpu(i, vcpu, kvm) { - int irq = dist->its_vm.vpes[i]->irq; - unsigned long irq_flags = DB_IRQ_FLAGS; - - /* - * Don't automatically enable the doorbell, as we're - * flipping it back and forth when the vcpu gets - * blocked. Also disable the lazy disabling, as the - * doorbell could kick us out of the guest too - * early... - * - * On GICv4.1, the doorbell is managed in HW and must - * be left enabled. - */ - if (kvm_vgic_global_state.has_gicv4_1) - irq_flags &= ~IRQ_NOAUTOEN; - irq_set_status_flags(irq, irq_flags); - - ret = request_irq(irq, vgic_v4_doorbell_handler, - 0, "vcpu", vcpu); - if (ret) { - kvm_err("failed to allocate vcpu IRQ%d\n", irq); - /* - * Trick: adjust the number of vpes so we know - * how many to nuke on teardown... - */ - dist->its_vm.nr_vpes = i; - break; - } - } - - if (ret) - vgic_v4_teardown(kvm); - - return ret; -} - -/** - * vgic_v4_teardown - Free the GICv4 data structures - * @kvm: Pointer to the VM being destroyed - * - * Relies on kvm->lock to be held. - */ -void vgic_v4_teardown(struct kvm *kvm) -{ - struct its_vm *its_vm = &kvm->arch.vgic.its_vm; - int i; - - if (!its_vm->vpes) - return; - - for (i = 0; i < its_vm->nr_vpes; i++) { - struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, i); - int irq = its_vm->vpes[i]->irq; - - irq_clear_status_flags(irq, DB_IRQ_FLAGS); - free_irq(irq, vcpu); - } - - its_free_vcpu_irqs(its_vm); - kfree(its_vm->vpes); - its_vm->nr_vpes = 0; - its_vm->vpes = NULL; -} - -int vgic_v4_put(struct kvm_vcpu *vcpu, bool need_db) -{ - struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; - - if (!vgic_supports_direct_msis(vcpu->kvm) || !vpe->resident) - return 0; - - return its_make_vpe_non_resident(vpe, need_db); -} - -int vgic_v4_load(struct kvm_vcpu *vcpu) -{ - struct its_vpe *vpe = &vcpu->arch.vgic_cpu.vgic_v3.its_vpe; - int err; - - if (!vgic_supports_direct_msis(vcpu->kvm) || vpe->resident) - return 0; - - /* - * Before making the VPE resident, make sure the redistributor - * corresponding to our current CPU expects us here. See the - * doc in drivers/irqchip/irq-gic-v4.c to understand how this - * turns into a VMOVP command at the ITS level. - */ - err = irq_set_affinity(vpe->irq, cpumask_of(smp_processor_id())); - if (err) - return err; - - err = its_make_vpe_resident(vpe, false, vcpu->kvm->arch.vgic.enabled); - if (err) - return err; - - /* - * Now that the VPE is resident, let's get rid of a potential - * doorbell interrupt that would still be pending. This is a - * GICv4.0 only "feature"... - */ - if (!kvm_vgic_global_state.has_gicv4_1) - err = irq_set_irqchip_state(vpe->irq, IRQCHIP_STATE_PENDING, false); - - return err; -} - -static struct vgic_its *vgic_get_its(struct kvm *kvm, - struct kvm_kernel_irq_routing_entry *irq_entry) -{ - struct kvm_msi msi = (struct kvm_msi) { - .address_lo = irq_entry->msi.address_lo, - .address_hi = irq_entry->msi.address_hi, - .data = irq_entry->msi.data, - .flags = irq_entry->msi.flags, - .devid = irq_entry->msi.devid, - }; - - return vgic_msi_to_its(kvm, &msi); -} - -int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq, - struct kvm_kernel_irq_routing_entry *irq_entry) -{ - struct vgic_its *its; - struct vgic_irq *irq; - struct its_vlpi_map map; - int ret; - - if (!vgic_supports_direct_msis(kvm)) - return 0; - - /* - * Get the ITS, and escape early on error (not a valid - * doorbell for any of our vITSs). - */ - its = vgic_get_its(kvm, irq_entry); - if (IS_ERR(its)) - return 0; - - mutex_lock(&its->its_lock); - - /* Perform the actual DevID/EventID -> LPI translation. */ - ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid, - irq_entry->msi.data, &irq); - if (ret) - goto out; - - /* - * Emit the mapping request. If it fails, the ITS probably - * isn't v4 compatible, so let's silently bail out. Holding - * the ITS lock should ensure that nothing can modify the - * target vcpu. - */ - map = (struct its_vlpi_map) { - .vm = &kvm->arch.vgic.its_vm, - .vpe = &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe, - .vintid = irq->intid, - .properties = ((irq->priority & 0xfc) | - (irq->enabled ? LPI_PROP_ENABLED : 0) | - LPI_PROP_GROUP1), - .db_enabled = true, - }; - - ret = its_map_vlpi(virq, &map); - if (ret) - goto out; - - irq->hw = true; - irq->host_irq = virq; - atomic_inc(&map.vpe->vlpi_count); - -out: - mutex_unlock(&its->its_lock); - return ret; -} - -int kvm_vgic_v4_unset_forwarding(struct kvm *kvm, int virq, - struct kvm_kernel_irq_routing_entry *irq_entry) -{ - struct vgic_its *its; - struct vgic_irq *irq; - int ret; - - if (!vgic_supports_direct_msis(kvm)) - return 0; - - /* - * Get the ITS, and escape early on error (not a valid - * doorbell for any of our vITSs). - */ - its = vgic_get_its(kvm, irq_entry); - if (IS_ERR(its)) - return 0; - - mutex_lock(&its->its_lock); - - ret = vgic_its_resolve_lpi(kvm, its, irq_entry->msi.devid, - irq_entry->msi.data, &irq); - if (ret) - goto out; - - WARN_ON(!(irq->hw && irq->host_irq == virq)); - if (irq->hw) { - atomic_dec(&irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe.vlpi_count); - irq->hw = false; - ret = its_unmap_vlpi(virq); - } - -out: - mutex_unlock(&its->its_lock); - return ret; -} |