On Fri, Oct 30, 2015 at 12:45 PM, Liu, Jijiang <jijiang.liu at intel.com> wrote:
> > If the driver correctly reports negotiated offload capabilities (see my > previous comment on patch 3), there is no need for the test on > VIRTIO_NET_F_CSUM, because application is not supposed to ask for offloads > on driver that do not support them. > > > > > > > If the driver correctly reports negotiated offload capabilities, then > application in guest will set the ol_flags in mbuf based on these offload > capabilities. > > If the VIRTIO_NET_F_CSUM is not enabled, and there is no need to call > virtqueue_enqueue_offload() to check ol_flags in mbuf to see if the TX > checksum and TSO is set ,and it will not effect on the performance of > disabling TX checksum path as much as possible. > > So I think there is need for the check. > You are supposed to only handle mbuf with offloads if VIRTIO_NET_F_CSUM was enabled in the first place through the capabilities. So looking at ol_flags means that you implicitely check for VIRTIO_NET_F_CSUM. This is just an optimisation, so do as you like. Anyway, I just want to confirm, is this patchset for 2.2 ? -- David Marchand
