4 * This module allows virtio devices to be used over a virtual PCI device.
5 * This can be used with QEMU based VMMs like KVM or Xen.
7 * Copyright IBM Corp. 2007
10 * Anthony Liguori <aliguori@us.ibm.com>
12 * This work is licensed under the terms of the GNU GPL, version 2 or later.
13 * See the COPYING file in the top-level directory.
17 #include <linux/module.h>
18 #include <linux/list.h>
19 #include <linux/pci.h>
20 #include <linux/interrupt.h>
21 #include <linux/virtio.h>
22 #include <linux/virtio_config.h>
23 #include <linux/virtio_ring.h>
24 #include <linux/virtio_pci.h>
25 #include <linux/highmem.h>
26 #include <linux/spinlock.h>
28 MODULE_AUTHOR("Anthony Liguori <aliguori@us.ibm.com>");
29 MODULE_DESCRIPTION("virtio-pci");
30 MODULE_LICENSE("GPL");
33 /* Our device structure */
34 struct virtio_pci_device
36 struct virtio_device vdev;
37 struct pci_dev *pci_dev;
39 /* the IO mapping for the PCI config space */
42 /* a list of queues so we can dispatch IRQs */
44 struct list_head virtqueues;
47 struct virtio_pci_vq_info
49 /* the actual virtqueue */
52 /* the number of entries in the queue */
55 /* the index of the queue */
58 /* the virtual address of the ring queue */
61 /* the list node for the virtqueues list */
62 struct list_head node;
65 /* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
66 static struct pci_device_id virtio_pci_id_table[] = {
67 { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
71 MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
73 /* A PCI device has it's own struct device and so does a virtio device so
74 * we create a place for the virtio devices to show up in sysfs. I think it
75 * would make more sense for virtio to not insist on having it's own device. */
76 static struct device virtio_pci_root = {
78 .bus_id = "virtio-pci",
81 /* Convert a generic virtio device to our structure */
82 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
84 return container_of(vdev, struct virtio_pci_device, vdev);
87 /* virtio config->get_features() implementation */
88 static u32 vp_get_features(struct virtio_device *vdev)
90 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
92 /* When someone needs more than 32 feature bits, we'll need to
93 * steal a bit to indicate that the rest are somewhere else. */
94 return ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
97 /* virtio config->finalize_features() implementation */
98 static void vp_finalize_features(struct virtio_device *vdev)
100 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
102 /* We only support 32 feature bits. */
103 BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
104 iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
107 /* virtio config->get() implementation */
108 static void vp_get(struct virtio_device *vdev, unsigned offset,
109 void *buf, unsigned len)
111 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
112 void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
116 for (i = 0; i < len; i++)
117 ptr[i] = ioread8(ioaddr + i);
120 /* the config->set() implementation. it's symmetric to the config->get()
122 static void vp_set(struct virtio_device *vdev, unsigned offset,
123 const void *buf, unsigned len)
125 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
126 void __iomem *ioaddr = vp_dev->ioaddr + VIRTIO_PCI_CONFIG + offset;
130 for (i = 0; i < len; i++)
131 iowrite8(ptr[i], ioaddr + i);
134 /* config->{get,set}_status() implementations */
135 static u8 vp_get_status(struct virtio_device *vdev)
137 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
138 return ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
141 static void vp_set_status(struct virtio_device *vdev, u8 status)
143 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
144 /* We should never be setting status to 0. */
146 iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
149 static void vp_reset(struct virtio_device *vdev)
151 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
152 /* 0 status means a reset. */
153 iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
156 /* the notify function used when creating a virt queue */
157 static void vp_notify(struct virtqueue *vq)
159 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
160 struct virtio_pci_vq_info *info = vq->priv;
162 /* we write the queue's selector into the notification register to
163 * signal the other end */
164 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
167 /* A small wrapper to also acknowledge the interrupt when it's handled.
168 * I really need an EIO hook for the vring so I can ack the interrupt once we
169 * know that we'll be handling the IRQ but before we invoke the callback since
170 * the callback may notify the host which results in the host attempting to
171 * raise an interrupt that we would then mask once we acknowledged the
173 static irqreturn_t vp_interrupt(int irq, void *opaque)
175 struct virtio_pci_device *vp_dev = opaque;
176 struct virtio_pci_vq_info *info;
177 irqreturn_t ret = IRQ_NONE;
181 /* reading the ISR has the effect of also clearing it so it's very
182 * important to save off the value. */
183 isr = ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
185 /* It's definitely not us if the ISR was not high */
189 /* Configuration change? Tell driver if it wants to know. */
190 if (isr & VIRTIO_PCI_ISR_CONFIG) {
191 struct virtio_driver *drv;
192 drv = container_of(vp_dev->vdev.dev.driver,
193 struct virtio_driver, driver);
195 if (drv->config_changed)
196 drv->config_changed(&vp_dev->vdev);
199 spin_lock_irqsave(&vp_dev->lock, flags);
200 list_for_each_entry(info, &vp_dev->virtqueues, node) {
201 if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
204 spin_unlock_irqrestore(&vp_dev->lock, flags);
209 /* the config->find_vq() implementation */
210 static struct virtqueue *vp_find_vq(struct virtio_device *vdev, unsigned index,
211 void (*callback)(struct virtqueue *vq))
213 struct virtio_pci_device *vp_dev = to_vp_device(vdev);
214 struct virtio_pci_vq_info *info;
215 struct virtqueue *vq;
220 /* Select the queue we're interested in */
221 iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
223 /* Check if queue is either not available or already active. */
224 num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
225 if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
226 return ERR_PTR(-ENOENT);
228 /* allocate and fill out our structure the represents an active
230 info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
232 return ERR_PTR(-ENOMEM);
234 info->queue_index = index;
237 info->queue = kzalloc(PAGE_ALIGN(vring_size(num,PAGE_SIZE)), GFP_KERNEL);
238 if (info->queue == NULL) {
243 /* activate the queue */
244 iowrite32(virt_to_phys(info->queue) >> PAGE_SHIFT,
245 vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
247 /* create the vring */
248 vq = vring_new_virtqueue(info->num, vdev, info->queue,
249 vp_notify, callback);
252 goto out_activate_queue;
258 spin_lock_irqsave(&vp_dev->lock, flags);
259 list_add(&info->node, &vp_dev->virtqueues);
260 spin_unlock_irqrestore(&vp_dev->lock, flags);
265 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
272 /* the config->del_vq() implementation */
273 static void vp_del_vq(struct virtqueue *vq)
275 struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
276 struct virtio_pci_vq_info *info = vq->priv;
279 spin_lock_irqsave(&vp_dev->lock, flags);
280 list_del(&info->node);
281 spin_unlock_irqrestore(&vp_dev->lock, flags);
283 vring_del_virtqueue(vq);
285 /* Select and deactivate the queue */
286 iowrite16(info->queue_index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
287 iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
293 static struct virtio_config_ops virtio_pci_config_ops = {
296 .get_status = vp_get_status,
297 .set_status = vp_set_status,
299 .find_vq = vp_find_vq,
301 .get_features = vp_get_features,
302 .finalize_features = vp_finalize_features,
305 /* the PCI probing function */
306 static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
307 const struct pci_device_id *id)
309 struct virtio_pci_device *vp_dev;
312 /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
313 if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
316 if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
317 printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
318 VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
322 /* allocate our structure and fill it out */
323 vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
327 vp_dev->vdev.dev.parent = &virtio_pci_root;
328 vp_dev->vdev.config = &virtio_pci_config_ops;
329 vp_dev->pci_dev = pci_dev;
330 INIT_LIST_HEAD(&vp_dev->virtqueues);
331 spin_lock_init(&vp_dev->lock);
333 /* enable the device */
334 err = pci_enable_device(pci_dev);
338 err = pci_request_regions(pci_dev, "virtio-pci");
340 goto out_enable_device;
342 vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
343 if (vp_dev->ioaddr == NULL)
344 goto out_req_regions;
346 pci_set_drvdata(pci_dev, vp_dev);
348 /* we use the subsystem vendor/device id as the virtio vendor/device
349 * id. this allows us to use the same PCI vendor/device id for all
350 * virtio devices and to identify the particular virtio driver by
351 * the subsytem ids */
352 vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
353 vp_dev->vdev.id.device = pci_dev->subsystem_device;
355 /* register a handler for the queue with the PCI device's interrupt */
356 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
357 vp_dev->vdev.dev.bus_id, vp_dev);
359 goto out_set_drvdata;
361 /* finally register the virtio device */
362 err = register_virtio_device(&vp_dev->vdev);
369 free_irq(pci_dev->irq, vp_dev);
371 pci_set_drvdata(pci_dev, NULL);
372 pci_iounmap(pci_dev, vp_dev->ioaddr);
374 pci_release_regions(pci_dev);
376 pci_disable_device(pci_dev);
382 static void __devexit virtio_pci_remove(struct pci_dev *pci_dev)
384 struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
386 unregister_virtio_device(&vp_dev->vdev);
387 free_irq(pci_dev->irq, vp_dev);
388 pci_set_drvdata(pci_dev, NULL);
389 pci_iounmap(pci_dev, vp_dev->ioaddr);
390 pci_release_regions(pci_dev);
391 pci_disable_device(pci_dev);
396 static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
398 pci_save_state(pci_dev);
399 pci_set_power_state(pci_dev, PCI_D3hot);
403 static int virtio_pci_resume(struct pci_dev *pci_dev)
405 pci_restore_state(pci_dev);
406 pci_set_power_state(pci_dev, PCI_D0);
411 static struct pci_driver virtio_pci_driver = {
412 .name = "virtio-pci",
413 .id_table = virtio_pci_id_table,
414 .probe = virtio_pci_probe,
415 .remove = virtio_pci_remove,
417 .suspend = virtio_pci_suspend,
418 .resume = virtio_pci_resume,
422 static int __init virtio_pci_init(void)
426 err = device_register(&virtio_pci_root);
430 err = pci_register_driver(&virtio_pci_driver);
432 device_unregister(&virtio_pci_root);
437 module_init(virtio_pci_init);
439 static void __exit virtio_pci_exit(void)
441 device_unregister(&virtio_pci_root);
442 pci_unregister_driver(&virtio_pci_driver);
445 module_exit(virtio_pci_exit);