| Message ID | 20250302143259.1221569-1-lulu@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | vhost: Add support of kthread API | expand |
QE tested this series of patches with virtio-net regression tests, everything works fine. Tested-by: Lei Yang <leiyang@redhat.com> On Sun, Mar 2, 2025 at 10:33 PM Cindy Lu <lulu@redhat.com> 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. > > 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 s. > > 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 > > Tested with QEMU with kthread mode/task mode/kthread+task mode > > Cindy Lu (8): > vhost: Add a new parameter in vhost_dev to allow user select kthread > vhost: Reintroduce vhost_worker to support kthread > vhost: Add the cgroup related function > vhost: Introduce vhost_worker_ops in vhost_worker > vhost: Reintroduce kthread mode support in vhost > vhost: uapi to control task mode (owner vs kthread) > vhost: Add check for inherit_owner status > vhost: Add a KConfig knob to enable IOCTL VHOST_FORK_FROM_OWNER > > drivers/vhost/Kconfig | 15 +++ > drivers/vhost/vhost.c | 227 +++++++++++++++++++++++++++++++++---- > drivers/vhost/vhost.h | 21 ++++ > include/uapi/linux/vhost.h | 15 +++ > 4 files changed, 259 insertions(+), 19 deletions(-) > > -- > 2.45.0 > >
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. 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 s. 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 Tested with QEMU with kthread mode/task mode/kthread+task mode Cindy Lu (8): vhost: Add a new parameter in vhost_dev to allow user select kthread vhost: Reintroduce vhost_worker to support kthread vhost: Add the cgroup related function vhost: Introduce vhost_worker_ops in vhost_worker vhost: Reintroduce kthread mode support in vhost vhost: uapi to control task mode (owner vs kthread) vhost: Add check for inherit_owner status vhost: Add a KConfig knob to enable IOCTL VHOST_FORK_FROM_OWNER drivers/vhost/Kconfig | 15 +++ drivers/vhost/vhost.c | 227 +++++++++++++++++++++++++++++++++---- drivers/vhost/vhost.h | 21 ++++ include/uapi/linux/vhost.h | 15 +++ 4 files changed, 259 insertions(+), 19 deletions(-)