Re: [Qemu-devel] is it just me or is ne2k broken in qemu?

[Luiz Capitulino <lcapitulino@redhat.com>]

On Sun, 17 Apr 2011 00:37:35 +0400
Michael Tokarev <mjt@tls.msk.ru> wrote:

> 15.04.2011 18:17, Alex Williamson wrote:
> > On Thu, 2011-04-14 at 12:31 +0400, Michael Tokarev wrote:
> 
> >> The NIC works for a while, but after a few packets,
> >> or a few 1000s of packets, it stalls.  In tcpdump
> >> on the host I see many ARP requests coming from the
> >> guest and each has corresponding ARP reply, but
> >> nothing is actually reaching the guest.
> 
> > For testing the iPXE ROMs I booted up each NIC, including ne2k_pci, to a
> > network loaded kernel (~4M) and installation initrd (~8M).  I stopped
> > the test at the point where the installer kernel was able to
> > successfully DHCP with the boot NIC.  ne2k_pci was definitely the
> > slowest of the cards at loading the images, but I didn't notice any
> > functionality issues.  Maybe I didn't let it run long enough, but the
> > boot ROM seems ok with it.
> 
> I'm doing exactly the same here, -- testing iPXE booting,
> so booting linux kernel over network.  I haven't been able
> to boot linux on ne2k so far, it fails somewhere down the
> road after loading initrd+kernel - either during initrd
> run or about after switching to new init (still running
> off network ofcourse) after mounting nfs root.
> 
> So when I encountered this issue I tried non-network boot
> and various versions of (linux) guest and qemu-kvm - and
> for me, ne2k always fail (stalls) after some time.
> 
> And Mulyadi Santosa mentioned it's apparently a known issue
> due to some timer-related problem in the code.

I've hit this issue today and I can reproduce it by downloading a
80M file with wget. My network configuration is:

 -net nic,model=ne2k_pci -net tap,ifname=vnet0,script=./qemu-ifup-switch

It also happens with qemu 0.12.5. I've also tried to enable the device's
debug and the last lines I see before it stalls *usually* are:

  E2000: read=0x07 val=0

or

  E2000: asic readl val=0xe283fad3

I'll try to reproduce with an older kernel version, but debugging
tips are welcome.