答复: why does virtio not support IPv4 CKSUM?

[jiangheng (G)]

>> Hi 
>> 
>> why does virtio not support IPv4 CKSUM? But support TCP/UDP cksum.

> Because virtio is a software driver developed on Linux and Linux doesn't need/want IP checksum offload.
> It takes longer to look at offload bits then to compute checksum in SW.

However, Virtio supports LRO. Is it possible to merge packets with incorrect cksum?

>> 
>> If not support ipv4 cksum, when I use GRO, the ip cksum of the packets transmitted to ip layer will be incorrect.
>> I have to calculate ip cksum before packet was transmiited to ip layer.
>> So why does virtio not support ipv4 cksum ?