RE: [virtio] [PATCH REQUIREMENTS v2 2/7] net-features: Add low latency transmit queue requirements

[Parav Pandit <parav@nvidia.com>]

> From: Stefan Hajnoczi <stefanha@redhat.com>
> Sent: Thursday, July 20, 2023 11:28 AM

> > +3. Packet transmit descriptor should be able to place a small size packet that
> > +   does not have any L4 data after the vnet_tx_hdr_desc in the virtqueue
> memory.
> 
> Please make this a generic virtqueue-level feature. It sounds like the idea is to
> vary the vring descriptor length per device type and per virtqueue so that
> headers and small payloads can be embedded directly into the vring.
>
First sorry for the delayed response. I am still recovering from illness and unable to work consistently.

Yes, should be possible with inlining the header.
Even within for same device type, for flow filters this is needed.

It largely applies to requester side queues like net txq, net flow filter q, cvq, blk/scsi req q.

Thanks for the input. Will update this requirement in v3.