24 Apr
2025
24 Apr
'25
9:06 a.m.
Mina Almasry almasrymina@google.com writes:
The bind-rx op has "flags: [ admin-perm ]", should bind-tx also?
The omission of admin-perm for tx is intentional.
Binding a dmabuf to an rx queue should and is a privileged operation, because basically the application doing the binding is taking ownership of this rx queue. For TX, no such queue ownership is being taken. The TX binding just gives the netdevice access to the dmabuf dma-addresses so the netdevice can send from there. It's very similar to a normal dma-map with normal memory. There is no need for privilege checks.
Thanks for the explanation. I couldn't find any mention of ownership in the docs.