[PATCH v7 3/8] vhost: Add the cgroup related function
From: Cindy Lu <hidden>
Date: 2025-03-02 14:33:39
Also in:
lkml, virtualization
Subsystem:
the rest, virtio host (vhost) · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Add back the previously removed cgroup function to support the kthread
The biggest change for this part is in vhost_attach_cgroups() and
vhost_attach_task_to_cgroups().
The old function was remove in
commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads")
Signed-off-by: Cindy Lu <redacted>
---
drivers/vhost/vhost.c | 41 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 9500e85b42ce..20571bd6f7bd 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c@@ -22,6 +22,7 @@ #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/kthread.h> +#include <linux/cgroup.h> #include <linux/module.h> #include <linux/sort.h> #include <linux/sched/mm.h>
@@ -620,6 +621,46 @@ long vhost_dev_check_owner(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_dev_check_owner); +struct vhost_attach_cgroups_struct { + struct vhost_work work; + struct task_struct *owner; + int ret; +}; + +static void vhost_attach_cgroups_work(struct vhost_work *work) +{ + struct vhost_attach_cgroups_struct *s; + + s = container_of(work, struct vhost_attach_cgroups_struct, work); + s->ret = cgroup_attach_task_all(s->owner, current); +} + +static int vhost_attach_task_to_cgroups(struct vhost_worker *worker) +{ + struct vhost_attach_cgroups_struct attach; + int saved_cnt; + + attach.owner = current; + + vhost_work_init(&attach.work, vhost_attach_cgroups_work); + vhost_worker_queue(worker, &attach.work); + + mutex_lock(&worker->mutex); + + /* + * Bypass attachment_cnt check in __vhost_worker_flush: + * Temporarily change it to INT_MAX to bypass the check + */ + saved_cnt = worker->attachment_cnt; + worker->attachment_cnt = INT_MAX; + __vhost_worker_flush(worker); + worker->attachment_cnt = saved_cnt; + + mutex_unlock(&worker->mutex); + + return attach.ret; +} + /* Caller should have device mutex */ bool vhost_dev_has_owner(struct vhost_dev *dev) {
--
2.45.0