/* * Virtio PCI driver - common functionality for all device versions * * This module allows virtio devices to be used over a virtual PCI device. * This can be used with QEMU based VMMs like KVM or Xen. * * Copyright IBM Corp. 2007 * Copyright Red Hat, Inc. 2014 * * Authors: * Anthony Liguori * Rusty Russell * Michael S. Tsirkin * * This work is licensed under the terms of the GNU GPL, version 2 or later. * See the COPYING file in the top-level directory. * */ #include "virtio_pci_common.h" static bool force_legacy = false; #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) module_param(force_legacy, bool, 0444); MODULE_PARM_DESC(force_legacy, "Force legacy mode for transitional virtio 1 devices"); #endif /* wait for pending irq handlers */ void vp_synchronize_vectors(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); int i; if (vp_dev->intx_enabled) synchronize_irq(vp_dev->pci_dev->irq); for (i = 0; i < vp_dev->msix_vectors; ++i) synchronize_irq(vp_dev->msix_entries[i].vector); } /* the notify function used when creating a virt queue */ bool vp_notify(struct virtqueue *vq) { /* we write the queue's selector into the notification register to * signal the other end */ iowrite16(vq->index, (void __iomem *)vq->priv); return true; } /* Handle a configuration change: Tell driver if it wants to know. */ static irqreturn_t vp_config_changed(int irq, void *opaque) { struct virtio_pci_device *vp_dev = opaque; virtio_config_changed(&vp_dev->vdev); return IRQ_HANDLED; } /* Notify all virtqueues on an interrupt. */ static irqreturn_t vp_vring_interrupt(int irq, void *opaque) { struct virtio_pci_device *vp_dev = opaque; struct virtio_pci_vq_info *info; irqreturn_t ret = IRQ_NONE; unsigned long flags; spin_lock_irqsave(&vp_dev->lock, flags); list_for_each_entry(info, &vp_dev->virtqueues, node) { if (vring_interrupt(irq, info->vq) == IRQ_HANDLED) ret = IRQ_HANDLED; } spin_unlock_irqrestore(&vp_dev->lock, flags); return ret; } /* A small wrapper to also acknowledge the interrupt when it's handled. * I really need an EIO hook for the vring so I can ack the interrupt once we * know that we'll be handling the IRQ but before we invoke the callback since * the callback may notify the host which results in the host attempting to * raise an interrupt that we would then mask once we acknowledged the * interrupt. */ static irqreturn_t vp_interrupt(int irq, void *opaque) { struct virtio_pci_device *vp_dev = opaque; u8 isr; /* reading the ISR has the effect of also clearing it so it's very * important to save off the value. */ isr = ioread8(vp_dev->isr); /* It's definitely not us if the ISR was not high */ if (!isr) return IRQ_NONE; /* Configuration change? Tell driver if it wants to know. */ if (isr & VIRTIO_PCI_ISR_CONFIG) vp_config_changed(irq, opaque); return vp_vring_interrupt(irq, opaque); } static void vp_free_vectors(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); int i; if (vp_dev->intx_enabled) { free_irq(vp_dev->pci_dev->irq, vp_dev); vp_dev->intx_enabled = 0; } for (i = 0; i < vp_dev->msix_used_vectors; ++i) free_irq(vp_dev->msix_entries[i].vector, vp_dev); for (i = 0; i < vp_dev->msix_vectors; i++) if (vp_dev->msix_affinity_masks[i]) free_cpumask_var(vp_dev->msix_affinity_masks[i]); if (vp_dev->msix_enabled) { /* Disable the vector used for configuration */ vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR); pci_disable_msix(vp_dev->pci_dev); vp_dev->msix_enabled = 0; } vp_dev->msix_vectors = 0; vp_dev->msix_used_vectors = 0; kfree(vp_dev->msix_names); vp_dev->msix_names = NULL; kfree(vp_dev->msix_entries); vp_dev->msix_entries = NULL; kfree(vp_dev->msix_affinity_masks); vp_dev->msix_affinity_masks = NULL; } static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, bool per_vq_vectors) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); const char *name = dev_name(&vp_dev->vdev.dev); unsigned i, v; int err = -ENOMEM; vp_dev->msix_vectors = nvectors; vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries, GFP_KERNEL); if (!vp_dev->msix_entries) goto error; vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names, GFP_KERNEL); if (!vp_dev->msix_names) goto error; vp_dev->msix_affinity_masks = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks, GFP_KERNEL); if (!vp_dev->msix_affinity_masks) goto error; for (i = 0; i < nvectors; ++i) if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i], GFP_KERNEL)) goto error; for (i = 0; i < nvectors; ++i) vp_dev->msix_entries[i].entry = i; err = pci_enable_msix_exact(vp_dev->pci_dev, vp_dev->msix_entries, nvectors); if (err) goto error; vp_dev->msix_enabled = 1; /* Set the vector used for configuration */ v = vp_dev->msix_used_vectors; snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names, "%s-config", name); err = request_irq(vp_dev->msix_entries[v].vector, vp_config_changed, 0, vp_dev->msix_names[v], vp_dev); if (err) goto error; ++vp_dev->msix_used_vectors; v = vp_dev->config_vector(vp_dev, v); /* Verify we had enough resources to assign the vector */ if (v == VIRTIO_MSI_NO_VECTOR) { err = -EBUSY; goto error; } if (!per_vq_vectors) { /* Shared vector for all VQs */ v = vp_dev->msix_used_vectors; snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names, "%s-virtqueues", name); err = request_irq(vp_dev->msix_entries[v].vector, vp_vring_interrupt, 0, vp_dev->msix_names[v], vp_dev); if (err) goto error; ++vp_dev->msix_used_vectors; } return 0; error: vp_free_vectors(vdev); return err; } static int vp_request_intx(struct virtio_device *vdev) { int err; struct virtio_pci_device *vp_dev = to_vp_device(vdev); err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED, dev_name(&vdev->dev), vp_dev); if (!err) vp_dev->intx_enabled = 1; return err; } static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index, void (*callback)(struct virtqueue *vq), const char *name, u16 msix_vec) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL); struct virtqueue *vq; unsigned long flags; /* fill out our structure that represents an active queue */ if (!info) return ERR_PTR(-ENOMEM); vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, msix_vec); if (IS_ERR(vq)) goto out_info; info->vq = vq; if (callback) { spin_lock_irqsave(&vp_dev->lock, flags); list_add(&info->node, &vp_dev->virtqueues); spin_unlock_irqrestore(&vp_dev->lock, flags); } else { INIT_LIST_HEAD(&info->node); } vp_dev->vqs[index] = info; return vq; out_info: kfree(info); return vq; } static void vp_del_vq(struct virtqueue *vq) { struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index]; unsigned long flags; spin_lock_irqsave(&vp_dev->lock, flags); list_del(&info->node); spin_unlock_irqrestore(&vp_dev->lock, flags); vp_dev->del_vq(info); kfree(info); } /* the config->del_vqs() implementation */ void vp_del_vqs(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtqueue *vq, *n; struct virtio_pci_vq_info *info; list_for_each_entry_safe(vq, n, &vdev->vqs, list) { info = vp_dev->vqs[vq->index]; if (vp_dev->per_vq_vectors && info->msix_vector != VIRTIO_MSI_NO_VECTOR) free_irq(vp_dev->msix_entries[info->msix_vector].vector, vq); vp_del_vq(vq); } vp_dev->per_vq_vectors = false; vp_free_vectors(vdev); kfree(vp_dev->vqs); vp_dev->vqs = NULL; } static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs, struct virtqueue *vqs[], vq_callback_t *callbacks[], const char * const names[], bool use_msix, bool per_vq_vectors) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); u16 msix_vec; int i, err, nvectors, allocated_vectors; vp_dev->vqs = kmalloc(nvqs * sizeof *vp_dev->vqs, GFP_KERNEL); if (!vp_dev->vqs) return -ENOMEM; if (!use_msix) { /* Old style: one normal interrupt for change and all vqs. */ err = vp_request_intx(vdev); if (err) goto error_find; } else { if (per_vq_vectors) { /* Best option: one for change interrupt, one per vq. */ nvectors = 1; for (i = 0; i < nvqs; ++i) if (callbacks[i]) ++nvectors; } else { /* Second best: one for change, shared for all vqs. */ nvectors = 2; } err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors); if (err) goto error_find; } vp_dev->per_vq_vectors = per_vq_vectors; allocated_vectors = vp_dev->msix_used_vectors; for (i = 0; i < nvqs; ++i) { if (!names[i]) { vqs[i] = NULL; continue; } else if (!callbacks[i] || !vp_dev->msix_enabled) msix_vec = VIRTIO_MSI_NO_VECTOR; else if (vp_dev->per_vq_vectors) msix_vec = allocated_vectors++; else msix_vec = VP_MSIX_VQ_VECTOR; vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], msix_vec); if (IS_ERR(vqs[i])) { err = PTR_ERR(vqs[i]); goto error_find; } if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR) continue; /* allocate per-vq irq if available and necessary */ snprintf(vp_dev->msix_names[msix_vec], sizeof *vp_dev->msix_names, "%s-%s", dev_name(&vp_dev->vdev.dev), names[i]); err = request_irq(vp_dev->msix_entries[msix_vec].vector, vring_interrupt, 0, vp_dev->msix_names[msix_vec], vqs[i]); if (err) { vp_del_vq(vqs[i]); goto error_find; } } return 0; error_find: vp_del_vqs(vdev); return err; } /* the config->find_vqs() implementation */ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, struct virtqueue *vqs[], vq_callback_t *callbacks[], const char * const names[]) { int err; /* Try MSI-X with one vector per queue. */ err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true); if (!err) return 0; /* Fallback: MSI-X with one vector for config, one shared for queues. */ err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, false); if (!err) return 0; /* Finally fall back to regular interrupts. */ return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, false, false); } const char *vp_bus_name(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); return pci_name(vp_dev->pci_dev); } /* Setup the affinity for a virtqueue: * - force the affinity for per vq vector * - OR over all affinities for shared MSI * - ignore the affinity request if we're using INTX */ int vp_set_vq_affinity(struct virtqueue *vq, int cpu) { struct virtio_device *vdev = vq->vdev; struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index]; struct cpumask *mask; unsigned int irq; if (!vq->callback) return -EINVAL; if (vp_dev->msix_enabled) { mask = vp_dev->msix_affinity_masks[info->msix_vector]; irq = vp_dev->msix_entries[info->msix_vector].vector; if (cpu == -1) irq_set_affinity_hint(irq, NULL); else { cpumask_clear(mask); cpumask_set_cpu(cpu, mask); irq_set_affinity_hint(irq, mask); } } return 0; } #ifdef CONFIG_PM_SLEEP static int virtio_pci_freeze(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); int ret; ret = virtio_device_freeze(&vp_dev->vdev); if (!ret) pci_disable_device(pci_dev); return ret; } static int virtio_pci_restore(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); int ret; ret = pci_enable_device(pci_dev); if (ret) return ret; pci_set_master(pci_dev); return virtio_device_restore(&vp_dev->vdev); } static const struct dev_pm_ops virtio_pci_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(virtio_pci_freeze, virtio_pci_restore) }; #endif /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */ static const struct pci_device_id virtio_pci_id_table[] = { { PCI_DEVICE(PCI_VENDOR_ID_REDHAT_QUMRANET, PCI_ANY_ID) }, { 0 } }; MODULE_DEVICE_TABLE(pci, virtio_pci_id_table); static void virtio_pci_release_dev(struct device *_d) { struct virtio_device *vdev = dev_to_virtio(_d); struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* As struct device is a kobject, it's not safe to * free the memory (including the reference counter itself) * until it's release callback. */ kfree(vp_dev); } static int virtio_pci_probe(struct pci_dev *pci_dev, const struct pci_device_id *id) { struct virtio_pci_device *vp_dev; int rc; /* allocate our structure and fill it out */ vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL); if (!vp_dev) return -ENOMEM; pci_set_drvdata(pci_dev, vp_dev); vp_dev->vdev.dev.parent = &pci_dev->dev; vp_dev->vdev.dev.release = virtio_pci_release_dev; vp_dev->pci_dev = pci_dev; INIT_LIST_HEAD(&vp_dev->virtqueues); spin_lock_init(&vp_dev->lock); /* enable the device */ rc = pci_enable_device(pci_dev); if (rc) goto err_enable_device; if (force_legacy) { rc = virtio_pci_legacy_probe(vp_dev); /* Also try modern mode if we can't map BAR0 (no IO space). */ if (rc == -ENODEV || rc == -ENOMEM) rc = virtio_pci_modern_probe(vp_dev); if (rc) goto err_probe; } else { rc = virtio_pci_modern_probe(vp_dev); if (rc == -ENODEV) rc = virtio_pci_legacy_probe(vp_dev); if (rc) goto err_probe; } pci_set_master(pci_dev); rc = register_virtio_device(&vp_dev->vdev); if (rc) goto err_register; return 0; err_register: if (vp_dev->ioaddr) virtio_pci_legacy_remove(vp_dev); else virtio_pci_modern_remove(vp_dev); err_probe: pci_disable_device(pci_dev); err_enable_device: kfree(vp_dev); return rc; } static void virtio_pci_remove(struct pci_dev *pci_dev) { struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev); unregister_virtio_device(&vp_dev->vdev); if (vp_dev->ioaddr) virtio_pci_legacy_remove(vp_dev); else virtio_pci_modern_remove(vp_dev); pci_disable_device(pci_dev); } static struct pci_driver virtio_pci_driver = { .name = "virtio-pci", .id_table = virtio_pci_id_table, .probe = virtio_pci_probe, .remove = virtio_pci_remove, #ifdef CONFIG_PM_SLEEP .driver.pm = &virtio_pci_pm_ops, #endif }; module_pci_driver(virtio_pci_driver); MODULE_AUTHOR("Anthony Liguori "); MODULE_DESCRIPTION("virtio-pci"); MODULE_LICENSE("GPL"); MODULE_VERSION("1");