lkml.org 
[lkml]   [2020]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Subject[RFC PATCH 1/7] vfio: Include optional device match in vfio_device_ops callbacks
    From
    Date
    Allow bus drivers to provide their own callback to match a device to
    the user provided string.

    Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
    ---
    drivers/vfio/vfio.c | 19 +++++++++++++++----
    include/linux/vfio.h | 3 +++
    2 files changed, 18 insertions(+), 4 deletions(-)

    diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
    index 388597930b64..dda1726adda8 100644
    --- a/drivers/vfio/vfio.c
    +++ b/drivers/vfio/vfio.c
    @@ -875,11 +875,22 @@ EXPORT_SYMBOL_GPL(vfio_device_get_from_dev);
    static struct vfio_device *vfio_device_get_from_name(struct vfio_group *group,
    char *buf)
    {
    - struct vfio_device *it, *device = NULL;
    + struct vfio_device *it, *device = ERR_PTR(-ENODEV);

    mutex_lock(&group->device_lock);
    list_for_each_entry(it, &group->device_list, group_next) {
    - if (!strcmp(dev_name(it->dev), buf)) {
    + int ret;
    +
    + if (it->ops->match) {
    + ret = it->ops->match(it->device_data, buf);
    + if (ret < 0 && ret != -ENODEV) {
    + device = ERR_PTR(ret);
    + break;
    + }
    + } else
    + ret = strcmp(dev_name(it->dev), buf);
    +
    + if (!ret) {
    device = it;
    vfio_device_get(device);
    break;
    @@ -1441,8 +1452,8 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
    return -EPERM;

    device = vfio_device_get_from_name(group, buf);
    - if (!device)
    - return -ENODEV;
    + if (IS_ERR(device))
    + return PTR_ERR(device);

    ret = device->ops->open(device->device_data);
    if (ret) {
    diff --git a/include/linux/vfio.h b/include/linux/vfio.h
    index e42a711a2800..755e0f0e2900 100644
    --- a/include/linux/vfio.h
    +++ b/include/linux/vfio.h
    @@ -26,6 +26,8 @@
    * operations documented below
    * @mmap: Perform mmap(2) on a region of the device file descriptor
    * @request: Request for the bus driver to release the device
    + * @match: Optional device name match callback (return: 0 for match, -ENODEV
    + * (or >0) for no match and continue, other -errno: no match and stop)
    */
    struct vfio_device_ops {
    char *name;
    @@ -39,6 +41,7 @@ struct vfio_device_ops {
    unsigned long arg);
    int (*mmap)(void *device_data, struct vm_area_struct *vma);
    void (*request)(void *device_data, unsigned int count);
    + int (*match)(void *device_data, char *buf);
    };

    extern struct iommu_group *vfio_iommu_group_get(struct device *dev);
    \
     
     \ /
      Last update: 2020-02-05 00:06    [W:3.051 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site