On Tue, Jan 27, 2015 at 03:57:13PM +0800, Linhaifeng wrote:
> Hi,all
>
> I use vhost-user to send data to VM at first it cant work well but after many
> hours VM can not receive data but can send data.
>
> (gdb)p avail_idx
> $4 = 2668
> (gdb)p free_entries
> $5 = 0
> (gdb)l
> /* check that we have enough buffers */
> if (unlikely(count > free_entries))
> count = free_entries;
>
> if (count == 0){
> int b=0;
> if(b) { // when set b=1 to notify guest rx_ring will restart to
> work
> if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
>
> eventfd_write(vq->callfd, 1);
> }
> }
> return 0;
> }
>
> some info i print in guest:
>
> net eth3:vi->num=199
> net eth3:rvq info: num_free=57, used->idx=2668, avail->idx=2668
> net eth3:svq info: num_free=254, used->idx=1644, avail->idx=1644
>
> net eth3:vi->num=199
> net eth3:rvq info: num_free=57, used->idx=2668, avail->idx=2668
> net eth3:svq info: num_free=254, used->idx=1645, avail->idx=1645
>
> net eth3:vi->num=199
> net eth3:rvq info: num_free=57, used->idx=2668, avail->idx=2668
> net eth3:svq info: num_free=254, used->idx=1646, avail->idx=1646
>
> # free
> total used free shared buffers cached
> Mem: 3924100 337252 3586848 0 95984 138060
> -/+ buffers/cache: 103208 3820892
> Swap: 970748 0 970748
>
> I have two questions:
> 1.Should we need to notify guest when there is no buffer in vq->avail?
No unless NOTIFY_ON_EMPTY is set (most guests don't set it).
> 2.Why virtio_net stop to fill avail?
Most likely, it didn't get an interrupt.
If so, it would be a dpdk vhost user bug.
Which code are you using in dpdk?
>
>
>
>
>
> --
> Regards,
> Haifeng
