Message-ID: <6a236a7c-e8a8-49c1-9407-749b9b6c9f95@blackwall.org>
Date: Mon, 19 Jan 2026 16:20:31 +0200
From: Nikolay Aleksandrov <razor@...ckwall.org>
To: Daniel Borkmann <daniel@...earbox.net>, netdev@...r.kernel.org
Cc: bpf@...r.kernel.org, kuba@...nel.org, davem@...emloft.net,
 pabeni@...hat.com, willemb@...gle.com, sdf@...ichev.me,
 john.fastabend@...il.com, martin.lau@...nel.org, jordan@...fe.io,
 maciej.fijalkowski@...el.com, magnus.karlsson@...el.com, dw@...idwei.uk,
 toke@...hat.com, yangzhenze@...edance.com, wangdongdong.6@...edance.com
Subject: Re: [PATCH net-next v7 01/16] net: Add queue-create operation

On 15/01/2026 10:25, Daniel Borkmann wrote:
> Add a ynl netdev family operation called queue-create that creates a
> new queue on a netdevice:
> 
>        name: queue-create
>        attribute-set: queue
>        flags: [admin-perm]
>        do:
>          request:
>            attributes:
>              - ifindex
>              - type
>              - lease
>          reply: &queue-create-op
>            attributes:
>              - id
> 
> This is a generic operation such that it can be extended for various
> use cases in future. Right now it is mandatory to specify ifindex,
> the queue type which is enforced to rx and a lease. The newly created
> queue id is returned to the caller.
> 
> A queue from a virtual device can have a lease which refers to another
> queue from a physical device. This is useful for memory providers
> and AF_XDP operations which take an ifindex and queue id to allow
> applications to bind against virtual devices in containers. The lease
> couples both queues together and allows to proxy the operations from
> a virtual device in a container to the physical device.
> 
> In future, the nested lease attribute can be lifted and made optional
> for other use-cases such as dynamic queue creation for physical
> netdevs. The lack of lease and the specification of the physical
> device as an ifindex will imply that we need a real queue to be
> allocated. Similarly, the queue type enforcement to rx can then be
> lifted as well to support tx.
> 
> An early implementation had only driver-specific integration [0], but
> in order for other virtual devices to reuse, it makes sense to have
> this as a generic API in core net.
> 
> For leasing queues, the virtual netdev must have real_num_rx_queue
> less than num_rx_queues at the time of calling queue-create. The
> queue-type must be rx as only rx queues are supported for leasing
> for now. We also enforce that the queue-create ifindex must point
> to a virtual device, and that the nested lease attribute's ifindex
> must point to a physical device. The nested lease attribute set
> contains a netns-id attribute which is currently only intended for
> dumping as part of the queue-get operation. Also, it is modeled as
> an s32 type similarly as done elsewhere in the stack.
> 
> Signed-off-by: Daniel Borkmann <daniel@...earbox.net>
> Co-developed-by: David Wei <dw@...idwei.uk>
> Signed-off-by: David Wei <dw@...idwei.uk>
> Link: https://bpfconf.ebpf.io/bpfconf2025/bpfconf2025_material/lsfmmbpf_2025_netkit_borkmann.pdf [0]
> ---
>   Documentation/netlink/specs/netdev.yaml | 44 +++++++++++++++++++++++++
>   include/uapi/linux/netdev.h             | 11 +++++++
>   net/core/netdev-genl-gen.c              | 20 +++++++++++
>   net/core/netdev-genl-gen.h              |  2 ++
>   net/core/netdev-genl.c                  |  5 +++
>   tools/include/uapi/linux/netdev.h       | 11 +++++++
>   6 files changed, 93 insertions(+)
> 

Reviewed-by: Nikolay Aleksandrov <razor@...ckwall.org>

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