On 09/03/2018 04:10 PM, Nikita Leshenko wrote: > On September 2, 2018 5:21:15 AM, fengguang.wu@xxxxxxxxx wrote: >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index 8b47507faab5..0c483720de8d 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -3892,6 +3892,7 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm) >> if (type == KVM_EVENT_CREATE_VM) { >> add_uevent_var(env, "EVENT=create"); >> kvm->userspace_pid = task_pid_nr(current); >> + current->kvm = kvm; > > Is it OK to store `kvm` on the task_struct? What if the thread that > originally created the VM exits? From the documentation it seems > like a VM is associated with an address space and not a specific > thread, so maybe it should be stored on mm_struct? Yes, ioctls accessing the kvm can happen from all threads. > > From Documentation/virtual/kvm/api.txt: > Only run VM ioctls from the same process (address space) that was used > to create the VM. > > -Nikita >> } else if (type == KVM_EVENT_DESTROY_VM) { >> add_uevent_var(env, "EVENT=destroy"); >> } >> -- >> 2.15.0 >> >> >> >