On 2018年04月25日 13:15, Tiwei Bie wrote:

Hello everyone,

This RFC implements packed ring support in virtio driver.

Some simple functional tests have been done with Jason's
packed ring implementation in vhost:

https://lkml.org/lkml/2018/4/23/12

Both of ping and netperf worked as expected (with EVENT_IDX
disabled). But there are below known issues:

1. Reloading the guest driver will break the Tx/Rx;

It looks like the reason is we don't sync wrap counter information 
between host and qemu through VHOST_SET/GET_VRING_BASE. And both vhost 
and qemu need to do this through encoding warp counters to higher bits 
of vhost_vring_state.num,

Thanks