On Tue, Aug 03, 2021 at 01:15:19PM +0200, Greg KH wrote: > > +/* > > + * Called after per-vm debugfs created. When called kvm->debugfs_dentry should > > + * be setup already, so we can create arch-specific debugfs entries under it. > > + * Cleanup should be automatic done in kvm_destroy_vm_debugfs() recursively, so > > + * a per-arch destroy interface is not needed. > > + */ > > +int __weak kvm_arch_create_vm_debugfs(struct kvm *kvm) > > This should be a void function, nothing should matter if creating > debugfs files succeeds or not. > > As proof, your one implementation always returned 0 :) Right. :) But we do have code that prepares for a failure on debugfs creations, please have a look at kvm_create_vm_debugfs(). So I kept that for per-arch hook. The existing x86 one should not fail, but it's a hope that we can convert some other arch's existing debugfs code into per-arch hook like what we did with x86 here. I didn't check again (please refer to the cover letter; we do have some of those), but it's still easier to still allow per-arch hook to fail the vm creation just like what we have for kvm_create_vm_debugfs(). PS: It makes sense to me to fail vm creation if 99% of those debugfs creation failures are about -ENOMEM; e.g. early failure sounds better than failing right after VM booted. Meanwhile, I never expected to receive comments from you; thanks for having a look! -- Peter Xu
