From mboxrd@z Thu Jan  1 00:00:00 1970
From: Linhaifeng <haifeng.lin-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Subject: Re: vhost: virtio-net rx-ring stop work after work many
 hours, bug?
Date: Tue, 3 Feb 2015 15:35:01 +0800
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To: "dpd >> dev-VfR2kkLFssw@public.gmane.org" <dev-VfR2kkLFssw@public.gmane.org>, "ms >> Michael S. Tsirkin"
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I found that the new code had try to notify guest after send each packet after 2bbb811.
So this bug not exist now.

static inline uint32_t __attribute__((always_inline)) virtio_dev_merge_rx(struct virtio_net *dev, uint16_t queue_id,
	struct rte_mbuf **pkts, uint32_t count) {
	... ...

	for (pkt_idx = 0; pkt_idx < count; pkt_idx++) {

		... ...

		/* Kick the guest if necessary. */
		if (!(vq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
			eventfd_write((int)vq->kickfd, 1);
	}

	return count;
}

thank you very much!

On 2015/1/27 15:57, 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?
> 2.Why virtio_net stop to fill avail?
> 
> 
> 
> 
> 
> 

-- 
Regards,
Haifeng