Re: [virtio-dev] Re: [PATCH v2 0/4] virtio: Clean up scatterlists and use the DMA API

[Paolo Bonzini <pbonzini@redhat.com>]

Il 28/08/2014 20:29, Christian Borntraeger ha scritto:
>>> >> block seems to work, with net a simple ping works, iperf causes this:
>> > 
>> > I neither see the bug, nor can I reproduce it on x86_64 on KVM.  I
>> > doubt that dma vs. non-dma is relevant.  I tried -net user a -net tap
>> > with iperf running in both directions.  I also tried switching
>> > virtio_pci into non-DMA-API mode.  No errors.
>> > 
>> > Is there any chance that you could instrument that BUG_ON to print n,
>> > i, in_sgs, out_sgs, total_sg, total_in, and total_out?  I assume this
>> > is some oddity with patch 1, but I'm mystified.
> Yes, its triggered by patch 1.

What version of QEMU?  Can you two cat the "features" file in the
virtio-net device's sysfs directory?

Paolo