On Mon, Aug 19, 2024 at 5:29 PM Cindy Lu <lulu@xxxxxxxxxx> wrote:
>
> Add a new UAPI to support setting the vhost device to
> use kthread mode. The user space application needs to use
> VHOST_SET_USE_KTHREAD to set the mode. This setting must
> be set before VHOST_SET_OWNER is set.
>
> Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
> ---
> drivers/vhost/vhost.c | 11 ++++++++++-
> include/uapi/linux/vhost.h | 2 ++
> 2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 0a7b2999100f..d6b71bddc272 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -2340,14 +2340,23 @@ long vhost_dev_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp)
> {
> struct eventfd_ctx *ctx;
> u64 p;
> - long r;
> + long r = 0;
> int i, fd;
> + bool kthread;
>
> /* If you are not the owner, you can become one */
> if (ioctl == VHOST_SET_OWNER) {
> r = vhost_dev_set_owner(d);
> goto done;
> }
> + if (ioctl == VHOST_SET_USE_KTHREAD) {
Btw, should we enforce this to be called when there's no owner?
> + if (copy_from_user(&kthread, argp, sizeof(kthread))) {
> + r = -EFAULT;
> + goto done;
> + }
> + use_kthread = kthread;
> + goto done;
> + }
>
> /* You must be the owner to do anything else */
> r = vhost_dev_check_owner(d);
> diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
> index b95dd84eef2d..386fe735da63 100644
> --- a/include/uapi/linux/vhost.h
> +++ b/include/uapi/linux/vhost.h
> @@ -235,4 +235,6 @@
> */
> #define VHOST_VDPA_GET_VRING_SIZE _IOWR(VHOST_VIRTIO, 0x82, \
> struct vhost_vring_state)
> +
> +#define VHOST_SET_USE_KTHREAD _IOW(VHOST_VIRTIO, 0x83, bool)
> #endif
> --
> 2.45.0
>
Thanks
