bc7f87a2c1
The current rte_vhost_dequeue_burst() implementation is a bit messy
and logic twisted. And you could see repeat code here and there.
However, rte_vhost_dequeue_burst() acutally does a simple job: copy
the packet data from vring desc to mbuf. What's tricky here is:
- desc buff could be chained (by desc->next field), so that you need
fetch next one if current is wholly drained.
- One mbuf could not be big enough to hold all desc buff, hence you
need to chain the mbuf as well, by the mbuf->next field.
The simplified code looks like following:
while (this_desc_is_not_drained_totally || has_next_desc) {
if (this_desc_has_drained_totally) {
this_desc = next_desc();
}
if (mbuf_has_no_room) {
mbuf = allocate_a_new_mbuf();
}
COPY(mbuf, desc);
}
Note that the old patch does a special handling for skipping virtio
header. However, that could be simply done by adjusting desc_avail
and desc_offset var:
desc_avail = desc->len - vq->vhost_hlen;
desc_offset = vq->vhost_hlen;
This refactor makes the code much more readable (IMO), yet it reduces
binary code size.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
DPDK is a set of libraries and drivers for fast packet processing. It supports many processor architectures and both FreeBSD and Linux. The DPDK uses the Open Source BSD license for the core libraries and drivers. The kernel components are GPLv2 licensed. Please check the doc directory for release notes, API documentation, and sample application information. For questions and usage discussions, subscribe to: users@dpdk.org Report bugs and issues to the development mailing list: dev@dpdk.org