On 01/17/2012 05:34 AM, Or Gerlitz wrote:
The new qp type designated usage is from user-space in Ethernet environments,
e.g by applications that do TCP/IP offloading. Only processes with the NET_RAW
capability may open such qp. The name raw packet was selected to resemble the
similarity to AF_PACKET / SOL_RAW sockets. Applications that use this qp type
should deal with whole packets, including link level headers.
This series allows to create such QPs and send packets over them. To receive
packets, flow steering support has to be added to the verbs and low-level
drivers. Flow Steering is the ability to program the HCA to direct a packet
which matches a given flow specification to a given QP. Flow specs set by
applications are typically made of L3 (IP) and L4 (TCP/UDP) based tuples,
where network drivers typically use L2 based tuples. Core and mlx4 patches
for flow steering are expected in the coming weeks.
Hey Or,
I think this series should add some new send flags for HW that does checksum
offload:
For example, cxgb4 supports these:
enum { /* TX_PKT_XT checksum types */
TX_CSUM_TCP = 0,
TX_CSUM_UDP = 1,
TX_CSUM_CRC16 = 4,
TX_CSUM_CRC32 = 5,
TX_CSUM_CRC32C = 6,
TX_CSUM_FCOE = 7,
TX_CSUM_TCPIP = 8,
TX_CSUM_UDPIP = 9,
TX_CSUM_TCPIP6 = 10,
TX_CSUM_UDPIP6 = 11,
TX_CSUM_IP = 12,
};
I'm sure mlx4 has this sort of functionality too?
Another form of HW assist is with VLAN insertion/extraction. The API should provide a way to specify if a VLAN ID
should be inserted by HW and removed from a packet on ingress (and passed to the app via the CQE). In fact, we probably
want a way to associate a VLAN with a RAW QP, maybe as a QP attribute?
Also, on ingress, most hardware can do INET checksum validation, and a way to indicate the results to the application is
needed. Perhaps flags in the CQE? The cxgb4 device provides many fields on a ingress packet completion that would be
useful for user mode applications including indications of MAC RX errors, protocol length vs packet length mismatches,
IP version not 4 or 6, and more. Does mlx4 has these sorts of indications on ingress packet CQEs?
Food for thought.
Steve.
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