/* * Virtio PCI driver * * 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 * * Authors: * Anthony Liguori * * 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 #include #include #include #include #include #include #include #include #include MODULE_AUTHOR("Anthony Liguori "); MODULE_DESCRIPTION("virtio-pci"); MODULE_LICENSE("GPL"); MODULE_VERSION("1"); /* Our device structure */ struct virtio_pci_device { struct virtio_device vdev; struct pci_dev *pci_dev; /* the IO mapping for the PCI config space */ void __iomem *ioaddr; /* a list of queues so we can dispatch IRQs */ spinlock_t lock; struct list_head virtqueues; }; struct virtio_pci_vq_info { /* the actual virtqueue */ struct virtqueue *vq; /* the number of entries in the queue */ int num; /* the index of the queue */ int queue_index; /* the virtual address of the ring queue */ void *queue; /* the list node for the virtqueues list */ struct list_head node; }; /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */ static struct pci_device_id virtio_pci_id_table[] = { { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 }, { 0 }, }; MODULE_DEVICE_TABLE(pci, virtio_pci_id_table); /* A PCI device has it's own struct device and so does a virtio device so * we create a place for the virtio devices to show up in sysfs. I think it * would make more sense for virtio to not insist on having it's own device. */ static struct device virtio_pci_root = { .parent = NULL, .bus_id = "virtio-pci", }; /* Convert a generic virtio device to our structure */ static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) { return container_of(vdev, struct virtio_pci_device, vdev); } /* virtio config->get_features() implementation */ static u32 vp_get_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* When someone needs more than 32 feature bits, we'll need to * steal a bit to indicate that the rest are somewhere else. */ return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES); } /* virtio config->finalize_features() implementation */ static void vp_finalize_features(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* Give virtio_ring a chance to accept features. */ vring_transport_features(vdev); /* We only support 32 feature bits. */ BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1); iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES); } /* virtio config->get() implementation */ static void vp_get(struct virtio_device *vdev, unsigned offset, void *buf, unsigned len) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset; u8 *ptr = buf; int i; for (i = 0; i < len; i++) ptr[i] = ioread8(ioaddr + i); } /* the config->set() implementation. it's symmetric to the config->get() * implementation */ static void vp_set(struct virtio_device *vdev, unsigned offset, const void *buf, unsigned len) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset; const u8 *ptr = buf; int i; for (i = 0; i < len; i++) iowrite8(ptr[i], ioaddr + i); } /* config->{get,set}_status() implementations */ static u8 vp_get_status(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS); } static void vp_set_status(struct virtio_device *vdev, u8 status) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* We should never be setting status to 0. */ BUG_ON(status == 0); iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS); } static void vp_reset(struct virtio_device *vdev) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); /* 0 status means a reset. */ iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS); } /* the notify function used when creating a virt queue */ static void vp_notify(struct virtqueue *vq) { struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev); struct virtio_pci_vq_info *info = vq->priv; /* we write the queue's selector into the notification register to * signal the other end */ iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY); } /* 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; struct virtio_pci_vq_info *info; irqreturn_t ret = IRQ_NONE; unsigned long flags; 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->ioaddr + VIRTIO_PCI_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) { struct virtio_driver *drv; drv = container_of(vp_dev->vdev.dev.driver, struct virtio_driver, driver); if (drv->config_changed) drv->config_changed(&vp_dev->vdev); } 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; } /* the config->find_vq() implementation */ static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index, void (*callback)(struct virtqueue *vq)) { struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtio_pci_vq_info *info; struct virtqueue *vq; unsigned long flags, size; u16 num; int err; /* Select the queue we're interested in */ iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); /* Check if queue is either not available or already active. */ num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM); if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN)) return ERR_PTR(-ENOENT); /* allocate and fill out our structure the represents an active * queue */ info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL); if (!info) return ERR_PTR(-ENOMEM); info->queue_index = index; info->num = num; size = PAGE_ALIGN(vring_size(num, PAGE_SIZE)); info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO); if (info->queue == NULL) { err = -ENOMEM; goto out_info; } /* activate the queue */ iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); /* create the vring */ vq = vring_new_virtqueue(info->num, vdev, info->queue, vp_notify, callback); if (!vq) { err = -ENOMEM; goto out_activate_queue; } vq->priv = info; info->vq = vq; spin_lock_irqsave(&vp_dev->lock, flags); list_add(&info->node, &vp_dev->virtqueues); spin_unlock_irqrestore(&vp_dev->lock, flags); return vq; out_activate_queue: iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); free_pages_exact(info->queue, size); out_info: kfree(info); return ERR_PTR(err); } /* the config->del_vq() implementation */ 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 = vq->priv; unsigned long flags, size; spin_lock_irqsave(&vp_dev->lock, flags); list_del(&info->node); spin_unlock_irqrestore(&vp_dev->lock, flags); vring_del_virtqueue(vq); /* Select and deactivate the queue */ iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL); iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN); size = PAGE_ALIGN(vring_size(info->num, PAGE_SIZE)); free_pages_exact(info->queue, size); kfree(info); } static struct virtio_config_ops virtio_pci_config_ops = { .get = vp_get, .set = vp_set, .get_status = vp_get_status, .set_status = vp_set_status, .reset = vp_reset, .find_vq = vp_find_vq, .del_vq = vp_del_vq, .get_features = vp_get_features, .finalize_features = vp_finalize_features, }; /* the PCI probing function */ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev, const struct pci_device_id *id) { struct virtio_pci_device *vp_dev; int err; /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */ if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f) return -ENODEV; if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) { printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n", VIRTIO_PCI_ABI_VERSION, pci_dev->revision); return -ENODEV; } /* allocate our structure and fill it out */ vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL); if (vp_dev == NULL) return -ENOMEM; vp_dev->vdev.dev.parent = &virtio_pci_root; vp_dev->vdev.config = &virtio_pci_config_ops; vp_dev->pci_dev = pci_dev; INIT_LIST_HEAD(&vp_dev->virtqueues); spin_lock_init(&vp_dev->lock); /* enable the device */ err = pci_enable_device(pci_dev); if (err) goto out; err = pci_request_regions(pci_dev, "virtio-pci"); if (err) goto out_enable_device; vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0); if (vp_dev->ioaddr == NULL) goto out_req_regions; pci_set_drvdata(pci_dev, vp_dev); /* we use the subsystem vendor/device id as the virtio vendor/device * id. this allows us to use the same PCI vendor/device id for all * virtio devices and to identify the particular virtio driver by * the subsytem ids */ vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor; vp_dev->vdev.id.device = pci_dev->subsystem_device; /* register a handler for the queue with the PCI device's interrupt */ err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED, vp_dev->vdev.dev.bus_id, vp_dev); if (err) goto out_set_drvdata; /* finally register the virtio device */ err = register_virtio_device(&vp_dev->vdev); if (err) goto out_req_irq; return 0; out_req_irq: free_irq(pci_dev->irq, vp_dev); out_set_drvdata: pci_set_drvdata(pci_dev, NULL); pci_iounmap(pci_dev, vp_dev->ioaddr); out_req_regions: pci_release_regions(pci_dev); out_enable_device: pci_disable_device(pci_dev); out: kfree(vp_dev); return err; } static void __devexit 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); free_irq(pci_dev->irq, vp_dev); pci_set_drvdata(pci_dev, NULL); pci_iounmap(pci_dev, vp_dev->ioaddr); pci_release_regions(pci_dev); pci_disable_device(pci_dev); kfree(vp_dev); } #ifdef CONFIG_PM static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state) { pci_save_state(pci_dev); pci_set_power_state(pci_dev, PCI_D3hot); return 0; } static int virtio_pci_resume(struct pci_dev *pci_dev) { pci_restore_state(pci_dev); pci_set_power_state(pci_dev, PCI_D0); return 0; } #endif 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 .suspend = virtio_pci_suspend, .resume = virtio_pci_resume, #endif }; static int __init virtio_pci_init(void) { int err; err = device_register(&virtio_pci_root); if (err) return err; err = pci_register_driver(&virtio_pci_driver); if (err) device_unregister(&virtio_pci_root); return err; } module_init(virtio_pci_init); static void __exit virtio_pci_exit(void) { device_unregister(&virtio_pci_root); pci_unregister_driver(&virtio_pci_driver); } module_exit(virtio_pci_exit);