On Monday, 2023-07-24 at 06:34:20 +03, Parav Pandit wrote:
> Add tx and rx packet timestamp requirements.
>
> Signed-off-by: Parav Pandit <>
Acked-by: David Edmondson <>
> ---
> net-workstream/features-1.4.md | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/net-workstream/features-1.4.md b/net-workstream/features-1.4.md
> index d228462..37820b6 100644
> --- a/net-workstream/features-1.4.md
> +++ b/net-workstream/features-1.4.md
> @@ -10,6 +10,7 @@ together is desired while updating the virtio net interface.
> 2. Low latency tx and rx virtqueues for PCI transport
> 3. Virtqueue notification coalescing re-arming support
> 4 Virtqueue receive flow filters (RFF)
> +5. Device timestamp for tx and rx packets
>
> # 3. Requirements
> ## 3.1 Device counters
> @@ -280,3 +281,28 @@ struct virtio_net_rff_delete {
> u8 padding[2];
> le32 flow_id;
> };
> +
> +## 3.5 Packet timestamp
> +1. Device should provide transmit timestamp and receive timestamp of the packets
> + at per packet level when the device is enabled.
> +2. Device should provide the current free running clock in the least latency
> + possible using an MMIO register read of 64-bit to have the least jitter.
> +3. Device should provide the current frequency and the frequency unit for the
> + software to synchronize the reference point of software and the device using
> + a control vq command.
> +
> +### 3.5.1 Transmit timestamp
> +1. Transmit completion must contain a packet transmission timestamp when the
> + device is enabled for it.
> +2. The device should record the packet transmit timestamp in the completion at
> + the farthest egress point towards the network.
> +3. The device must provide a transmit packet timestamp in a single DMA
> + transaction along with the rest of the transmit completion fields.
> +
> +### 3.5.2 Receive timestamp
> +1. Receive completion must contain a packet reception timestamp when the device
> + is enabled for it.
> +2. The device should record the received packet timestamp at the closet ingress
> + point of reception from the network.
> +3. The device should provide a receive packet timestamp in a single DMA
> + transaction along with the rest of the receive completion fields.
--
Do not leave the building.
