/* * Kernel-based Virtual Machine - device assignment support * * Copyright (C) 2010 Red Hat, Inc. and/or its affiliates. * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * */ #include <linux/kvm_host.h> #include <linux/kvm.h> #include <linux/uaccess.h> #include <linux/vmalloc.h> #include <linux/errno.h> #include <linux/spinlock.h> #include <linux/pci.h> #include <linux/interrupt.h> #include <linux/slab.h> #include "irq.h" static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head, int assigned_dev_id) { struct list_head *ptr; struct kvm_assigned_dev_kernel *match; list_for_each(ptr, head) { match = list_entry(ptr, struct kvm_assigned_dev_kernel, list); if (match->assigned_dev_id == assigned_dev_id) return match; } return NULL; } static int find_index_from_host_irq(struct kvm_assigned_dev_kernel *assigned_dev, int irq) { int i, index; struct msix_entry *host_msix_entries; host_msix_entries = assigned_dev->host_msix_entries; index = -1; for (i = 0; i < assigned_dev->entries_nr; i++) if (irq == host_msix_entries[i].vector) { index = i; break; } if (index < 0) { printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n"); return 0; } return index; } static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) { struct kvm_assigned_dev_kernel *assigned_dev; int i; assigned_dev = container_of(work, struct kvm_assigned_dev_kernel, interrupt_work); spin_lock_irq(&assigned_dev->assigned_dev_lock); if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) { struct kvm_guest_msix_entry *guest_entries = assigned_dev->guest_msix_entries; for (i = 0; i < assigned_dev->entries_nr; i++) { if (!(guest_entries[i].flags & KVM_ASSIGNED_MSIX_PENDING)) continue; guest_entries[i].flags &= ~KVM_ASSIGNED_MSIX_PENDING; kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, guest_entries[i].vector, 1); } } else kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id, assigned_dev->guest_irq, 1); spin_unlock_irq(&assigned_dev->assigned_dev_lock); } static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) { unsigned long flags; struct kvm_assigned_dev_kernel *assigned_dev = (struct kvm_assigned_dev_kernel *) dev_id; spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags); if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) { int index = find_index_from_host_irq(assigned_dev, irq); if (index < 0) goto out; assigned_dev->guest_msix_entries[index].flags |= KVM_ASSIGNED_MSIX_PENDING; } schedule_work(&assigned_dev->interrupt_work); if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) { disable_irq_nosync(irq); assigned_dev->host_irq_disabled = true; } out: spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags); return IRQ_HANDLED; } /* Ack the irq line for an assigned device */ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) { struct kvm_assigned_dev_kernel *dev; unsigned long flags; if (kian->gsi == -1) return; dev = container_of(kian, struct kvm_assigned_dev_kernel, ack_notifier); kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0); /* The guest irq may be shared so this ack may be * from another device. */ spin_lock_irqsave(&dev->assigned_dev_lock, flags); if (dev->host_irq_disabled) { enable_irq(dev->host_irq); dev->host_irq_disabled = false; } spin_unlock_irqrestore(&dev->assigned_dev_lock, flags); } static void deassign_guest_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier); assigned_dev->ack_notifier.gsi = -1; if (assigned_dev->irq_source_id != -1) kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id); assigned_dev->irq_source_id = -1; assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK); } /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */ static void deassign_host_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { /* * In kvm_free_device_irq, cancel_work_sync return true if: * 1. work is scheduled, and then cancelled. * 2. work callback is executed. * * The first one ensured that the irq is disabled and no more events * would happen. But for the second one, the irq may be enabled (e.g. * for MSI). So we disable irq here to prevent further events. * * Notice this maybe result in nested disable if the interrupt type is * INTx, but it's OK for we are going to free it. * * If this function is a part of VM destroy, please ensure that till * now, the kvm state is still legal for probably we also have to wait * interrupt_work done. */ if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) { int i; for (i = 0; i < assigned_dev->entries_nr; i++) disable_irq_nosync(assigned_dev-> host_msix_entries[i].vector); cancel_work_sync(&assigned_dev->interrupt_work); for (i = 0; i < assigned_dev->entries_nr; i++) free_irq(assigned_dev->host_msix_entries[i].vector, (void *)assigned_dev); assigned_dev->entries_nr = 0; kfree(assigned_dev->host_msix_entries); kfree(assigned_dev->guest_msix_entries); pci_disable_msix(assigned_dev->dev); } else { /* Deal with MSI and INTx */ disable_irq_nosync(assigned_dev->host_irq); cancel_work_sync(&assigned_dev->interrupt_work); free_irq(assigned_dev->host_irq, (void *)assigned_dev); if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI) pci_disable_msi(assigned_dev->dev); } assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK); } static int kvm_deassign_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev, unsigned long irq_requested_type) { unsigned long guest_irq_type, host_irq_type; if (!irqchip_in_kernel(kvm)) return -EINVAL; /* no irq assignment to deassign */ if (!assigned_dev->irq_requested_type) return -ENXIO; host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK; guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK; if (host_irq_type) deassign_host_irq(kvm, assigned_dev); if (guest_irq_type) deassign_guest_irq(kvm, assigned_dev); return 0; } static void kvm_free_assigned_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type); } static void kvm_free_assigned_device(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { kvm_free_assigned_irq(kvm, assigned_dev); pci_reset_function(assigned_dev->dev); pci_release_regions(assigned_dev->dev); pci_disable_device(assigned_dev->dev); pci_dev_put(assigned_dev->dev); list_del(&assigned_dev->list); kfree(assigned_dev); } void kvm_free_all_assigned_devices(struct kvm *kvm) { struct list_head *ptr, *ptr2; struct kvm_assigned_dev_kernel *assigned_dev; list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) { assigned_dev = list_entry(ptr, struct kvm_assigned_dev_kernel, list); kvm_free_assigned_device(kvm, assigned_dev); } } static int assigned_device_enable_host_intx(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev) { dev->host_irq = dev->dev->irq; /* Even though this is PCI, we don't want to use shared * interrupts. Sharing host devices with guest-assigned devices * on the same interrupt line is not a happy situation: there * are going to be long delays in accepting, acking, etc. */ if (request_irq(dev->host_irq, kvm_assigned_dev_intr, 0, "kvm_assigned_intx_device", (void *)dev)) return -EIO; return 0; } #ifdef __KVM_HAVE_MSI static int assigned_device_enable_host_msi(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev) { int r; if (!dev->dev->msi_enabled) { r = pci_enable_msi(dev->dev); if (r) return r; } dev->host_irq = dev->dev->irq; if (request_irq(dev->host_irq, kvm_assigned_dev_intr, 0, "kvm_assigned_msi_device", (void *)dev)) { pci_disable_msi(dev->dev); return -EIO; } return 0; } #endif #ifdef __KVM_HAVE_MSIX static int assigned_device_enable_host_msix(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev) { int i, r = -EINVAL; /* host_msix_entries and guest_msix_entries should have been * initialized */ if (dev->entries_nr == 0) return r; r = pci_enable_msix(dev->dev, dev->host_msix_entries, dev->entries_nr); if (r) return r; for (i = 0; i < dev->entries_nr; i++) { r = request_irq(dev->host_msix_entries[i].vector, kvm_assigned_dev_intr, 0, "kvm_assigned_msix_device", (void *)dev); if (r) goto err; } return 0; err: for (i -= 1; i >= 0; i--) free_irq(dev->host_msix_entries[i].vector, (void *)dev); pci_disable_msix(dev->dev); return r; } #endif static int assigned_device_enable_guest_intx(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev, struct kvm_assigned_irq *irq) { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = irq->guest_irq; return 0; } #ifdef __KVM_HAVE_MSI static int assigned_device_enable_guest_msi(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev, struct kvm_assigned_irq *irq) { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; dev->host_irq_disabled = false; return 0; } #endif #ifdef __KVM_HAVE_MSIX static int assigned_device_enable_guest_msix(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev, struct kvm_assigned_irq *irq) { dev->guest_irq = irq->guest_irq; dev->ack_notifier.gsi = -1; dev->host_irq_disabled = false; return 0; } #endif static int assign_host_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev, __u32 host_irq_type) { int r = -EEXIST; if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK) return r; switch (host_irq_type) { case KVM_DEV_IRQ_HOST_INTX: r = assigned_device_enable_host_intx(kvm, dev); break; #ifdef __KVM_HAVE_MSI case KVM_DEV_IRQ_HOST_MSI: r = assigned_device_enable_host_msi(kvm, dev); break; #endif #ifdef __KVM_HAVE_MSIX case KVM_DEV_IRQ_HOST_MSIX: r = assigned_device_enable_host_msix(kvm, dev); break; #endif default: r = -EINVAL; } if (!r) dev->irq_requested_type |= host_irq_type; return r; } static int assign_guest_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *dev, struct kvm_assigned_irq *irq, unsigned long guest_irq_type) { int id; int r = -EEXIST; if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK) return r; id = kvm_request_irq_source_id(kvm); if (id < 0) return id; dev->irq_source_id = id; switch (guest_irq_type) { case KVM_DEV_IRQ_GUEST_INTX: r = assigned_device_enable_guest_intx(kvm, dev, irq); break; #ifdef __KVM_HAVE_MSI case KVM_DEV_IRQ_GUEST_MSI: r = assigned_device_enable_guest_msi(kvm, dev, irq); break; #endif #ifdef __KVM_HAVE_MSIX case KVM_DEV_IRQ_GUEST_MSIX: r = assigned_device_enable_guest_msix(kvm, dev, irq); break; #endif default: r = -EINVAL; } if (!r) { dev->irq_requested_type |= guest_irq_type; kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier); } else kvm_free_irq_source_id(kvm, dev->irq_source_id); return r; } /* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm, struct kvm_assigned_irq *assigned_irq) { int r = -EINVAL; struct kvm_assigned_dev_kernel *match; unsigned long host_irq_type, guest_irq_type; if (!irqchip_in_kernel(kvm)) return r; mutex_lock(&kvm->lock); r = -ENODEV; match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, assigned_irq->assigned_dev_id); if (!match) goto out; host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK); guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK); r = -EINVAL; /* can only assign one type at a time */ if (hweight_long(host_irq_type) > 1) goto out; if (hweight_long(guest_irq_type) > 1) goto out; if (host_irq_type == 0 && guest_irq_type == 0) goto out; r = 0; if (host_irq_type) r = assign_host_irq(kvm, match, host_irq_type); if (r) goto out; if (guest_irq_type) r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type); out: mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm, struct kvm_assigned_irq *assigned_irq) { int r = -ENODEV; struct kvm_assigned_dev_kernel *match; mutex_lock(&kvm->lock); match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, assigned_irq->assigned_dev_id); if (!match) goto out; r = kvm_deassign_irq(kvm, match, assigned_irq->flags); out: mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_assign_device(struct kvm *kvm, struct kvm_assigned_pci_dev *assigned_dev) { int r = 0, idx; struct kvm_assigned_dev_kernel *match; struct pci_dev *dev; mutex_lock(&kvm->lock); idx = srcu_read_lock(&kvm->srcu); match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, assigned_dev->assigned_dev_id); if (match) { /* device already assigned */ r = -EEXIST; goto out; } match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL); if (match == NULL) { printk(KERN_INFO "%s: Couldn't allocate memory\n", __func__); r = -ENOMEM; goto out; } dev = pci_get_domain_bus_and_slot(assigned_dev->segnr, assigned_dev->busnr, assigned_dev->devfn); if (!dev) { printk(KERN_INFO "%s: host device not found\n", __func__); r = -EINVAL; goto out_free; } if (pci_enable_device(dev)) { printk(KERN_INFO "%s: Could not enable PCI device\n", __func__); r = -EBUSY; goto out_put; } r = pci_request_regions(dev, "kvm_assigned_device"); if (r) { printk(KERN_INFO "%s: Could not get access to device regions\n", __func__); goto out_disable; } pci_reset_function(dev); match->assigned_dev_id = assigned_dev->assigned_dev_id; match->host_segnr = assigned_dev->segnr; match->host_busnr = assigned_dev->busnr; match->host_devfn = assigned_dev->devfn; match->flags = assigned_dev->flags; match->dev = dev; spin_lock_init(&match->assigned_dev_lock); match->irq_source_id = -1; match->kvm = kvm; match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq; INIT_WORK(&match->interrupt_work, kvm_assigned_dev_interrupt_work_handler); list_add(&match->list, &kvm->arch.assigned_dev_head); if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) { if (!kvm->arch.iommu_domain) { r = kvm_iommu_map_guest(kvm); if (r) goto out_list_del; } r = kvm_assign_device(kvm, match); if (r) goto out_list_del; } out: srcu_read_unlock(&kvm->srcu, idx); mutex_unlock(&kvm->lock); return r; out_list_del: list_del(&match->list); pci_release_regions(dev); out_disable: pci_disable_device(dev); out_put: pci_dev_put(dev); out_free: kfree(match); srcu_read_unlock(&kvm->srcu, idx); mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_deassign_device(struct kvm *kvm, struct kvm_assigned_pci_dev *assigned_dev) { int r = 0; struct kvm_assigned_dev_kernel *match; mutex_lock(&kvm->lock); match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, assigned_dev->assigned_dev_id); if (!match) { printk(KERN_INFO "%s: device hasn't been assigned before, " "so cannot be deassigned\n", __func__); r = -EINVAL; goto out; } if (match->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) kvm_deassign_device(kvm, match); kvm_free_assigned_device(kvm, match); out: mutex_unlock(&kvm->lock); return r; } #ifdef __KVM_HAVE_MSIX static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm, struct kvm_assigned_msix_nr *entry_nr) { int r = 0; struct kvm_assigned_dev_kernel *adev; mutex_lock(&kvm->lock); adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, entry_nr->assigned_dev_id); if (!adev) { r = -EINVAL; goto msix_nr_out; } if (adev->entries_nr == 0) { adev->entries_nr = entry_nr->entry_nr; if (adev->entries_nr == 0 || adev->entries_nr >= KVM_MAX_MSIX_PER_DEV) { r = -EINVAL; goto msix_nr_out; } adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr, GFP_KERNEL); if (!adev->host_msix_entries) { r = -ENOMEM; goto msix_nr_out; } adev->guest_msix_entries = kzalloc( sizeof(struct kvm_guest_msix_entry) * entry_nr->entry_nr, GFP_KERNEL); if (!adev->guest_msix_entries) { kfree(adev->host_msix_entries); r = -ENOMEM; goto msix_nr_out; } } else /* Not allowed set MSI-X number twice */ r = -EINVAL; msix_nr_out: mutex_unlock(&kvm->lock); return r; } static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm, struct kvm_assigned_msix_entry *entry) { int r = 0, i; struct kvm_assigned_dev_kernel *adev; mutex_lock(&kvm->lock); adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head, entry->assigned_dev_id); if (!adev) { r = -EINVAL; goto msix_entry_out; } for (i = 0; i < adev->entries_nr; i++) if (adev->guest_msix_entries[i].vector == 0 || adev->guest_msix_entries[i].entry == entry->entry) { adev->guest_msix_entries[i].entry = entry->entry; adev->guest_msix_entries[i].vector = entry->gsi; adev->host_msix_entries[i].entry = entry->entry; break; } if (i == adev->entries_nr) { r = -ENOSPC; goto msix_entry_out; } msix_entry_out: mutex_unlock(&kvm->lock); return r; } #endif long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl, unsigned long arg) { void __user *argp = (void __user *)arg; int r = -ENOTTY; switch (ioctl) { case KVM_ASSIGN_PCI_DEVICE: { struct kvm_assigned_pci_dev assigned_dev; r = -EFAULT; if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev)) goto out; r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev); if (r) goto out; break; } case KVM_ASSIGN_IRQ: { r = -EOPNOTSUPP; break; } #ifdef KVM_CAP_ASSIGN_DEV_IRQ case KVM_ASSIGN_DEV_IRQ: { struct kvm_assigned_irq assigned_irq; r = -EFAULT; if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq)) goto out; r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq); if (r) goto out; break; } case KVM_DEASSIGN_DEV_IRQ: { struct kvm_assigned_irq assigned_irq; r = -EFAULT; if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq)) goto out; r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq); if (r) goto out; break; } #endif #ifdef KVM_CAP_DEVICE_DEASSIGNMENT case KVM_DEASSIGN_PCI_DEVICE: { struct kvm_assigned_pci_dev assigned_dev; r = -EFAULT; if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev)) goto out; r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev); if (r) goto out; break; } #endif #ifdef KVM_CAP_IRQ_ROUTING case KVM_SET_GSI_ROUTING: { struct kvm_irq_routing routing; struct kvm_irq_routing __user *urouting; struct kvm_irq_routing_entry *entries; r = -EFAULT; if (copy_from_user(&routing, argp, sizeof(routing))) goto out; r = -EINVAL; if (routing.nr >= KVM_MAX_IRQ_ROUTES) goto out; if (routing.flags) goto out; r = -ENOMEM; entries = vmalloc(routing.nr * sizeof(*entries)); if (!entries) goto out; r = -EFAULT; urouting = argp; if (copy_from_user(entries, urouting->entries, routing.nr * sizeof(*entries))) goto out_free_irq_routing; r = kvm_set_irq_routing(kvm, entries, routing.nr, routing.flags); out_free_irq_routing: vfree(entries); break; } #endif /* KVM_CAP_IRQ_ROUTING */ #ifdef __KVM_HAVE_MSIX case KVM_ASSIGN_SET_MSIX_NR: { struct kvm_assigned_msix_nr entry_nr; r = -EFAULT; if (copy_from_user(&entry_nr, argp, sizeof entry_nr)) goto out; r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr); if (r) goto out; break; } case KVM_ASSIGN_SET_MSIX_ENTRY: { struct kvm_assigned_msix_entry entry; r = -EFAULT; if (copy_from_user(&entry, argp, sizeof entry)) goto out; r = kvm_vm_ioctl_set_msix_entry(kvm, &entry); if (r) goto out; break; } #endif } out: return r; }