#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/stat.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
struct vfio_container {
struct kref kref;
struct list_head group_list;
- struct mutex group_lock;
+ struct rw_semaphore group_lock;
struct vfio_iommu_driver *iommu_driver;
void *iommu_data;
};
}
/* Device reference always implies a group reference */
-static void vfio_device_put(struct vfio_device *device)
+void vfio_device_put(struct vfio_device *device)
{
struct vfio_group *group = device->group;
kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock);
vfio_group_put(group);
}
+EXPORT_SYMBOL_GPL(vfio_device_put);
static void vfio_device_get(struct vfio_device *device)
{
}
EXPORT_SYMBOL_GPL(vfio_add_group_dev);
+/**
+ * Get a reference to the vfio_device for a device that is known to
+ * be bound to a vfio driver. The driver implicitly holds a
+ * vfio_device reference between vfio_add_group_dev and
+ * vfio_del_group_dev. We can therefore use drvdata to increment
+ * that reference from the struct device. This additional
+ * reference must be released by calling vfio_device_put.
+ */
+struct vfio_device *vfio_device_get_from_dev(struct device *dev)
+{
+ struct vfio_device *device = dev_get_drvdata(dev);
+
+ vfio_device_get(device);
+
+ return device;
+}
+EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
+
+/*
+ * Caller must hold a reference to the vfio_device
+ */
+void *vfio_device_data(struct vfio_device *device)
+{
+ return device->device_data;
+}
+EXPORT_SYMBOL_GPL(vfio_device_data);
+
/* Given a referenced group, check if it contains the device */
static bool vfio_dev_present(struct vfio_group *group, struct device *dev)
{
static long vfio_ioctl_check_extension(struct vfio_container *container,
unsigned long arg)
{
- struct vfio_iommu_driver *driver = container->iommu_driver;
+ struct vfio_iommu_driver *driver;
long ret = 0;
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+
switch (arg) {
/* No base extensions yet */
default:
VFIO_CHECK_EXTENSION, arg);
}
+ up_read(&container->group_lock);
+
return ret;
}
-/* hold container->group_lock */
+/* hold write lock on container->group_lock */
static int __vfio_container_attach_groups(struct vfio_container *container,
struct vfio_iommu_driver *driver,
void *data)
struct vfio_iommu_driver *driver;
long ret = -ENODEV;
- mutex_lock(&container->group_lock);
+ down_write(&container->group_lock);
/*
* The container is designed to be an unprivileged interface while
* the container is deprivileged and returns to an unset state.
*/
if (list_empty(&container->group_list) || container->iommu_driver) {
- mutex_unlock(&container->group_lock);
+ up_write(&container->group_lock);
return -EINVAL;
}
mutex_unlock(&vfio.iommu_drivers_lock);
skip_drivers_unlock:
- mutex_unlock(&container->group_lock);
+ up_write(&container->group_lock);
return ret;
}
if (!container)
return ret;
- driver = container->iommu_driver;
- data = container->iommu_data;
-
switch (cmd) {
case VFIO_GET_API_VERSION:
ret = VFIO_API_VERSION;
ret = vfio_ioctl_set_iommu(container, arg);
break;
default:
+ down_read(&container->group_lock);
+
+ driver = container->iommu_driver;
+ data = container->iommu_data;
+
if (driver) /* passthrough all unrecognized ioctls */
ret = driver->ops->ioctl(data, cmd, arg);
+
+ up_read(&container->group_lock);
}
return ret;
return -ENOMEM;
INIT_LIST_HEAD(&container->group_list);
- mutex_init(&container->group_lock);
+ init_rwsem(&container->group_lock);
kref_init(&container->kref);
filep->private_data = container;
size_t count, loff_t *ppos)
{
struct vfio_container *container = filep->private_data;
- struct vfio_iommu_driver *driver = container->iommu_driver;
+ struct vfio_iommu_driver *driver;
+ ssize_t ret = -EINVAL;
- if (unlikely(!driver || !driver->ops->read))
- return -EINVAL;
+ down_read(&container->group_lock);
- return driver->ops->read(container->iommu_data, buf, count, ppos);
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->read))
+ ret = driver->ops->read(container->iommu_data,
+ buf, count, ppos);
+
+ up_read(&container->group_lock);
+
+ return ret;
}
static ssize_t vfio_fops_write(struct file *filep, const char __user *buf,
size_t count, loff_t *ppos)
{
struct vfio_container *container = filep->private_data;
- struct vfio_iommu_driver *driver = container->iommu_driver;
+ struct vfio_iommu_driver *driver;
+ ssize_t ret = -EINVAL;
- if (unlikely(!driver || !driver->ops->write))
- return -EINVAL;
+ down_read(&container->group_lock);
- return driver->ops->write(container->iommu_data, buf, count, ppos);
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->write))
+ ret = driver->ops->write(container->iommu_data,
+ buf, count, ppos);
+
+ up_read(&container->group_lock);
+
+ return ret;
}
static int vfio_fops_mmap(struct file *filep, struct vm_area_struct *vma)
{
struct vfio_container *container = filep->private_data;
- struct vfio_iommu_driver *driver = container->iommu_driver;
+ struct vfio_iommu_driver *driver;
+ int ret = -EINVAL;
- if (unlikely(!driver || !driver->ops->mmap))
- return -EINVAL;
+ down_read(&container->group_lock);
- return driver->ops->mmap(container->iommu_data, vma);
+ driver = container->iommu_driver;
+ if (likely(driver && driver->ops->mmap))
+ ret = driver->ops->mmap(container->iommu_data, vma);
+
+ up_read(&container->group_lock);
+
+ return ret;
}
static const struct file_operations vfio_fops = {
struct vfio_container *container = group->container;
struct vfio_iommu_driver *driver;
- mutex_lock(&container->group_lock);
+ down_write(&container->group_lock);
driver = container->iommu_driver;
if (driver)
container->iommu_data = NULL;
}
- mutex_unlock(&container->group_lock);
+ up_write(&container->group_lock);
vfio_container_put(container);
}
container = f.file->private_data;
WARN_ON(!container); /* fget ensures we don't race vfio_release */
- mutex_lock(&container->group_lock);
+ down_write(&container->group_lock);
driver = container->iommu_driver;
if (driver) {
atomic_inc(&group->container_users);
unlock_out:
- mutex_unlock(&container->group_lock);
+ up_write(&container->group_lock);
fdput(f);
return ret;
}
*/
static char *vfio_devnode(struct device *dev, umode_t *mode)
{
+ if (mode && (MINOR(dev->devt) == 0))
+ *mode = S_IRUGO | S_IWUGO;
+
return kasprintf(GFP_KERNEL, "vfio/%s", dev_name(dev));
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff