[PATCH v11 0/3] vhost: Add support of kthread API

[Cindy Lu <lulu@redhat.com>]

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.

Changelog v6:
 1. move the check of VHOST_NEW_WORKER from vhost_scsi to vhost
 2. Change the ioctl name VHOST_SET_INHERIT_FROM_OWNER to VHOST_FORK_FROM_OWNER
 3. reuse the function __vhost_worker_flush
 4. use a ops sturct to support worker relates function
 5. reset the value of inherit_owner in vhost_dev_reset_owner.
 
Changelog v7: 
 1. add a KConfig knob to disable legacy app support
 2. Split the changes into two patches to separately introduce the ops and add kthread support.
 3. Utilized INX_MAX to avoid modifications in __vhost_worker_flush
 4. Rebased on the latest kernel
 5. Address other comments
 
Changelog v8: 
 1. Rebased on the latest kernel
 2. Address some other comments 
 
Changelog v9:
 1. Rebased on the latest kernel. 
 2. Squashed patches 6‑7. 
 3. Squashed patches 2‑4. 
 4. Minor fixes in commit log
 
Changelog v10:
 1.Add support for the module_param.
 2.Squash patches 3 and 4.
 3.Make minor fixes in the commit log.
 4.Fix the mismatched tabs in Kconfig.
 5.Rebase on the latest kernel.

Changelog v11:
 1.make the module_param under Kconfig
 2.Make minor fixes in the commit log.
 3.change the name inherit_owner to fork_owner
 4.add NEW ioctl VHOST_GET_FORK_FROM_OWNER
 5.Rebase on the latest kernel
     
Tested with QEMU with kthread mode/task mode/kthread+task mode

Cindy Lu (3):
  vhost: Add a new parameter in vhost_dev to allow user select kthread
  vhost: Reintroduce kthread mode support in vhost
  vhost: Add configuration controls for vhost worker's mode

 drivers/vhost/Kconfig      |  17 +++
 drivers/vhost/vhost.c      | 234 ++++++++++++++++++++++++++++++++++---
 drivers/vhost/vhost.h      |  22 ++++
 include/uapi/linux/vhost.h |  25 ++++
 4 files changed, 280 insertions(+), 18 deletions(-)

-- 
2.45.0