[PATCH v4 0/1] KVM: trigger uevents when creating or destroying a VM

From: Claudio Imbrenda
Date: Tue Jul 11 2017 - 08:13:02 EST

This patch adds a few lines to the KVM common code to fire a
KOBJ_CHANGE uevent whenever a KVM VM is created or destroyed. The event
carries five environment variables:

CREATED indicates how many times a new VM has been created. It is
useful for example to trigger specific actions when the first
VM is started
COUNT indicates how many VMs are currently active. This can be used for
logging or monitoring purposes
PID has the pid of the KVM process that has been started or stopped.
This can be used to perform process-specific tuning.
STATS_PATH contains the path in debugfs to the directory with all the
runtime statistics for this VM. This is useful for performance
monitoring and profiling.
EVENT described the type of event, its value can be either "create" or

Specific udev rules can be then set up in userspace to deal with the
creation or destruction of VMs as needed.

v3 -> v4:
* fixed subject line
* reworked kvm_uevent_notify_change to use struct kobj_uevent_env and
add_uevent_var for improved readability.

v2 -> v3:
* added EVENT
* shortened the names of the other variables

v1 -> v2:
* some cleanup, the patch should look nicer now
* rebased on 4.12

Claudio Imbrenda (1):
KVM: trigger uevents when creating or destroying a VM

virt/kvm/kvm_main.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 74 insertions(+)