Re: [RFC][PATCH 1/5] [PATCH 1/5] kvm: register in task_struct

[Nikita Leshenko]

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?

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
> 
> 
>