![Rusty Russell](/assets/img/avatar_default.png)
The virtio code never hooked through the ->remove callback. Although noone supports device removal at the moment, this code is already needed for module unloading. This of course also revealed bugs in virtio_blk, virtio_net and lguest unloading paths. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
203 lines
5.2 KiB
C
203 lines
5.2 KiB
C
#include <linux/virtio.h>
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#include <linux/spinlock.h>
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#include <linux/virtio_config.h>
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static ssize_t device_show(struct device *_d,
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struct device_attribute *attr, char *buf)
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{
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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return sprintf(buf, "%hu", dev->id.device);
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}
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static ssize_t vendor_show(struct device *_d,
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struct device_attribute *attr, char *buf)
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{
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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return sprintf(buf, "%hu", dev->id.vendor);
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}
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static ssize_t status_show(struct device *_d,
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struct device_attribute *attr, char *buf)
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{
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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return sprintf(buf, "0x%08x", dev->config->get_status(dev));
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}
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static ssize_t modalias_show(struct device *_d,
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struct device_attribute *attr, char *buf)
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{
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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return sprintf(buf, "virtio:d%08Xv%08X\n",
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dev->id.device, dev->id.vendor);
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}
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static struct device_attribute virtio_dev_attrs[] = {
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__ATTR_RO(device),
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__ATTR_RO(vendor),
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__ATTR_RO(status),
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__ATTR_RO(modalias),
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__ATTR_NULL
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};
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static inline int virtio_id_match(const struct virtio_device *dev,
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const struct virtio_device_id *id)
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{
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if (id->device != dev->id.device)
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return 0;
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return id->vendor == VIRTIO_DEV_ANY_ID || id->vendor != dev->id.vendor;
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}
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/* This looks through all the IDs a driver claims to support. If any of them
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* match, we return 1 and the kernel will call virtio_dev_probe(). */
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static int virtio_dev_match(struct device *_dv, struct device_driver *_dr)
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{
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unsigned int i;
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struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
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const struct virtio_device_id *ids;
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ids = container_of(_dr, struct virtio_driver, driver)->id_table;
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for (i = 0; ids[i].device; i++)
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if (virtio_id_match(dev, &ids[i]))
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return 1;
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return 0;
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}
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static int virtio_uevent(struct device *_dv, struct kobj_uevent_env *env)
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{
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struct virtio_device *dev = container_of(_dv,struct virtio_device,dev);
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return add_uevent_var(env, "MODALIAS=virtio:d%08Xv%08X",
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dev->id.device, dev->id.vendor);
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}
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static struct bus_type virtio_bus = {
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.name = "virtio",
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.match = virtio_dev_match,
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.dev_attrs = virtio_dev_attrs,
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.uevent = virtio_uevent,
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};
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static void add_status(struct virtio_device *dev, unsigned status)
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{
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dev->config->set_status(dev, dev->config->get_status(dev) | status);
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}
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static int virtio_dev_probe(struct device *_d)
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{
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int err;
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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struct virtio_driver *drv = container_of(dev->dev.driver,
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struct virtio_driver, driver);
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add_status(dev, VIRTIO_CONFIG_S_DRIVER);
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err = drv->probe(dev);
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if (err)
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add_status(dev, VIRTIO_CONFIG_S_FAILED);
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else
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add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
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return err;
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}
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static int virtio_dev_remove(struct device *_d)
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{
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struct virtio_device *dev = container_of(_d,struct virtio_device,dev);
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struct virtio_driver *drv = container_of(dev->dev.driver,
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struct virtio_driver, driver);
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dev->config->set_status(dev, dev->config->get_status(dev)
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& ~VIRTIO_CONFIG_S_DRIVER);
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drv->remove(dev);
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return 0;
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}
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int register_virtio_driver(struct virtio_driver *driver)
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{
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driver->driver.bus = &virtio_bus;
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driver->driver.probe = virtio_dev_probe;
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driver->driver.remove = virtio_dev_remove;
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return driver_register(&driver->driver);
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}
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EXPORT_SYMBOL_GPL(register_virtio_driver);
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void unregister_virtio_driver(struct virtio_driver *driver)
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{
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driver_unregister(&driver->driver);
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}
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EXPORT_SYMBOL_GPL(unregister_virtio_driver);
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int register_virtio_device(struct virtio_device *dev)
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{
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int err;
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dev->dev.bus = &virtio_bus;
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sprintf(dev->dev.bus_id, "%u", dev->index);
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/* Acknowledge that we've seen the device. */
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add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE);
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/* device_register() causes the bus infrastructure to look for a
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* matching driver. */
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err = device_register(&dev->dev);
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if (err)
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add_status(dev, VIRTIO_CONFIG_S_FAILED);
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return err;
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}
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EXPORT_SYMBOL_GPL(register_virtio_device);
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void unregister_virtio_device(struct virtio_device *dev)
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{
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device_unregister(&dev->dev);
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}
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EXPORT_SYMBOL_GPL(unregister_virtio_device);
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int __virtio_config_val(struct virtio_device *vdev,
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u8 type, void *val, size_t size)
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{
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void *token;
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unsigned int len;
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token = vdev->config->find(vdev, type, &len);
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if (!token)
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return -ENOENT;
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if (len != size)
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return -EIO;
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vdev->config->get(vdev, token, val, size);
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return 0;
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}
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EXPORT_SYMBOL_GPL(__virtio_config_val);
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int virtio_use_bit(struct virtio_device *vdev,
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void *token, unsigned int len, unsigned int bitnum)
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{
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unsigned long bits[16];
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/* This makes it convenient to pass-through find() results. */
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if (!token)
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return 0;
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/* bit not in range of this bitfield? */
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if (bitnum * 8 >= len / 2)
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return 0;
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/* Giant feature bitfields are silly. */
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BUG_ON(len > sizeof(bits));
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vdev->config->get(vdev, token, bits, len);
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if (!test_bit(bitnum, bits))
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return 0;
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/* Set acknowledge bit, and write it back. */
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set_bit(bitnum + len * 8 / 2, bits);
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vdev->config->set(vdev, token, bits, len);
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return 1;
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}
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EXPORT_SYMBOL_GPL(virtio_use_bit);
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static int virtio_init(void)
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{
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if (bus_register(&virtio_bus) != 0)
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panic("virtio bus registration failed");
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return 0;
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}
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core_initcall(virtio_init);
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