On Mon, Dec 30, 2024 at 08:43:47PM +0800, Cindy Lu wrote:

In commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads"),   
the vhost now uses vhost_task and operates as a child of the   
owner thread. This aligns with containerization principles.   
However, this change has caused confusion for some legacy   
userspace applications. Therefore, we are reintroducing   
support for the kthread API.  

I briefly applied this, but there seem to be a bit too
many nits. So I will wait for v6 with everything addressed.

Thanks!

In this series, a new UAPI is implemented to allow   
userspace applications to configure their thread mode. 

Changelog v2:
 1. Change the module_param's name to enforce_inherit_owner, and the default value is true.
 2. Change the UAPI's name to VHOST_SET_INHERIT_FROM_OWNER.
 
Changelog v3:
 1. Change the module_param's name to inherit_owner_default, and the default value is true.
 2. Add a structure for task function; the worker will select a different mode based on the value inherit_owner.
 3. device will have their own inherit_owner in struct vhost_dev
 4. Address other comments

Changelog v4: 
 1. remove the module_param, only keep the UAPI
 2. remove the structure for task function; change to use the function pointer in vhost_worker
 3. fix the issue in vhost_worker_create and vhost_dev_ioctl
 4. Address other comments

Changelog v5: 
 1. Change wakeup and stop function pointers in struct vhost_worker to void.
 2. merging patches 4, 5, 6 in a single patch
 3. Fix spelling issues and address other comments.
 
Tested with QEMU with kthread mode/task mode/kthread+task mode

Cindy Lu (6):
  vhost: Add a new parameter in vhost_dev to allow user select kthread
  vhost: Add the vhost_worker to support kthread
  vhost: Add the cgroup related function
  vhost: Add worker related functions to support kthread
  vhost: Add new UAPI to support change to task mode
  vhost_scsi: Add check for inherit_owner status

 drivers/vhost/scsi.c       |   8 ++
 drivers/vhost/vhost.c      | 178 +++++++++++++++++++++++++++++++++----
 drivers/vhost/vhost.h      |   4 +
 include/uapi/linux/vhost.h |  19 ++++
 4 files changed, 192 insertions(+), 17 deletions(-)

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2.45.0