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 "destroy" Specific udev rules can be then set up in userspace to deal with the creation or destruction of VMs as needed. v4 -> v5: * fixed compilation issue when cgroups are not configured 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: * added KVM_VM_PID and KVM_VM_STATS_PATH * 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 | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) -- 2.7.4
