On Fri, 20 Jul 2018 10:19:25 +0800
Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx> wrote:
> For special mdev type which can aggregate instances for mdev device,
> this extends mdev create interface by allowing extra "instances=xxx"
> parameter, which is passed to mdev device model to be able to create
> arbitrary bundled number of instances for target mdev device.
>
> v2: create new create_with_instances operator for vendor driver
>
> Cc: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
> Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
> ---
> drivers/vfio/mdev/mdev_core.c | 18 +++++++++++++----
> drivers/vfio/mdev/mdev_private.h | 5 ++++-
> drivers/vfio/mdev/mdev_sysfs.c | 34 ++++++++++++++++++++++++++------
> include/linux/mdev.h | 10 ++++++++++
> 4 files changed, 56 insertions(+), 11 deletions(-)
>
(...)
> diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
> index 249472f05509..a06e5b7c69d3 100644
> --- a/drivers/vfio/mdev/mdev_sysfs.c
> +++ b/drivers/vfio/mdev/mdev_sysfs.c
> @@ -54,11 +54,15 @@ static const struct sysfs_ops mdev_type_sysfs_ops = {
> static ssize_t create_store(struct kobject *kobj, struct device *dev,
> const char *buf, size_t count)
> {
> - char *str;
> + char *str, *opt = NULL;
> uuid_le uuid;
> int ret;
> + unsigned int instances = 1;
>
> - if ((count < UUID_STRING_LEN) || (count > UUID_STRING_LEN + 1))
> + if (count < UUID_STRING_LEN)
> + return -EINVAL;
> +
> + if (count > UUID_STRING_LEN + 1 + MDEV_CREATE_OPT_LEN)
Do you plan to have other optional parameters? If you don't, you could
probably do a quick exit here if count is between UUID_STRING_LEN + 1
and UUID_STRING_LEN + 12 (for ",instances=<one digit>")?
> return -EINVAL;
>
> str = kstrndup(buf, count, GFP_KERNEL);
(...)
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index b6e048e1045f..cfb702600f95 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -30,6 +30,13 @@ struct mdev_device;
> * @kobj: kobject of type for which 'create' is called.
> * @mdev: mdev_device structure on of mediated device
> * that is being created
> + * @create_with_instances: Allocate aggregated instances' resources in parent device's
> + * driver for a particular mediated device. It is optional
> + * if doesn't support aggregated resources.
"Optional if aggregated resources are not supported"
> + * @kobj: kobject of type for which 'create' is called.
> + * @mdev: mdev_device structure on of mediated device
> + * that is being created
> + * @instances: number of instances to aggregate
> * Returns integer: success (0) or error (< 0)
You need that "Returns" line for both the old and the new ops.
> * @remove: Called to free resources in parent device's driver for a
> * a mediated device. It is mandatory to provide 'remove'
> @@ -71,6 +78,9 @@ struct mdev_parent_ops {
> struct attribute_group **supported_type_groups;
>
> int (*create)(struct kobject *kobj, struct mdev_device *mdev);
> + int (*create_with_instances)(struct kobject *kobj,
> + struct mdev_device *mdev,
> + unsigned int instances);
> int (*remove)(struct mdev_device *mdev);
> int (*open)(struct mdev_device *mdev);
> void (*release)(struct mdev_device *mdev);
