Mike Christie e297cd54b3 vhost_task: Allow vhost layer to use copy_process ... Qemu will create vhost devices in the kernel which perform network, SCSI, etc IO and management operations from worker threads created by the kthread API. Because the kthread API does a copy_process on the kthreadd thread, the vhost layer has to use kthread_use_mm to access the Qemu thread's memory and cgroup_attach_task_all to add itself to the Qemu thread's cgroups, and it bypasses the RLIMIT_NPROC limit which can result in VMs creating more threads than the admin expected. This patch adds a new struct vhost_task which can be used instead of kthreads. They allow the vhost layer to use copy_process and inherit the userspace process's mm and cgroups, the task is accounted for under the userspace's nproc count and can be seen in its process tree, and other features like namespaces work and are inherited by default. Signed-off-by: Mike Christie <michael.christie@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Christian Brauner <brauner@kernel.org>		2023-03-23 12:45:36 +01:00
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affinity.h
autogroup.h
clock.h	sched/clock: Make local_clock() noinstr	2023-01-31 15:01:47 +01:00
cond_resched.h
coredump.h	mm: implement memory-deny-write-execute as a prctl	2023-02-02 22:33:24 -08:00
cpufreq.h
cputime.h	cputime: remove cputime_to_nsecs fallback	2022-12-27 12:52:17 +01:00
deadline.h
debug.h
hotplug.h
idle.h	cpuidle, sched: Remove instrumentation from TIF_{POLLING_NRFLAG,NEED_RESCHED}	2023-01-13 11:48:16 +01:00
init.h
isolation.h
jobctl.h
loadavg.h
mm.h
nohz.h
numa_balancing.h
posix-timers.h
prio.h
rseq_api.h
rt.h
sd_flags.h
signal.h
smt.h
stat.h
sysctl.h	sched: Move numa_balancing sysctls to its own file	2022-11-20 20:55:26 -08:00
task.h	fork: allow kernel code to call copy_process	2023-03-12 10:54:43 +01:00
task_flags.h
task_stack.h
thread_info_api.h
topology.h
types.h
user.h	kernel/user: Allow user_struct::locked_vm to be usable for iommufd	2022-11-30 20:16:49 -04:00
vhost_task.h	vhost_task: Allow vhost layer to use copy_process	2023-03-23 12:45:36 +01:00
wake_q.h
xacct.h