Re: [Qemu-discuss] Defining a bridge

[Aleksei]

Ok, try loading virtio_net module - it will load some dependencies as well (virtio and virtio_ring I think).

--Regards, Aleksei

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From: Jerry Stuckle
Sent: Monday, October 17, 2016 9:46PM
To: Aleksei
Subject: Re: [Qemu-discuss] Defining a bridge

Alekse,

Thanks again for the help.  Answers below.

On 10/17/2016 12:10 PM, Aleksei wrote:

I didn't even notice before that you're emulating ARM :) It should
indeed be "-device virtio-net-device,netdev=net0 \" then - it is placed
on virtio-bus instead of PCI. Can you run "lsmod | grep virtio" in
Debian and also post your Debian's kernel version?

It showed the module virtio was not loaded.  Adding the module to
/etc/modules allowed it to be loaded on a reboot, but still no interface
to the bridge (only lo).  Debian version is 3.2.0-4-vexpress (latest
version from Debian stable).

Just to be sure that you're all good with bridging stuff - can you run
"ip l l" in Ubuntu (when your Debian VM is running) and see if there are
both bridge0 and tap0 interfaces present? If they are, then the only
problem is Debian not seeing virtio-bus and/or virtio NIC.

Yes, they show:

2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
master bridge0 state UP mode DEFAULT group default qlen 1000
    link/ether 08:00:27:f7:2b:c1 brd ff:ff:ff:ff:ff:ff

4: bridge0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UP mode DEFAULT group default qlen 1000
    link/ether 08:00:27:f7:2b:c1 brd ff:ff:ff:ff:ff:ff

5: tap0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
master bridge0 state UNKNOWN mode DEFAULT group default qlen 1000

So it looks like Debian is not seeing the NIC.

I never emulated ARM, so I have only guesses as to where to poke around;
but you might get an answer straight away on Qemu ARM mailing list -
http://wiki.qemu.org/MailingLists.

/--Regards, Aleksei/

Yes, I can try this, also.  I would appreciate it if you have any other
ideas.

Thanks again for all of your time and help.

Jerry

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*From:* Jerry Stuckle
*Sent:* Monday, October 17, 2016 5:36PM
*To:* Aleksei
*Subject:* Re: [Qemu-discuss] Defining a bridge

On 10/17/2016 2:07 AM, Aleksei wrote:

Hi,

-device virtio-net-device,netdev=net0 \

This should be -device virtio-net,netdev=net0 \

/--Regards, Aleksei/

Hi, Aleksei,

Thanks for the response.  That was one of the many things I had tried
before (really too many failures to list here :) ), but that fails with

qemu-system-arm: -device virtio-net,netdev=net0: No 'PCI' bus found for
device 'virtio-net-pci'

Which is correct because ARM devices do not have a PCI bus.

Jerry

------------------------------------------------------------------------

*From:* Jerry Stuckle
*Sent:* Monday, October 17, 2016 5:20AM
*To:* Qemu-discuss
*Subject:* [Qemu-discuss] Defining a bridge

Hi,

OK, I'm back on this now, and need to define a bridge for qemu.

Once again, this is Ubuntu running in VirtualBox under Windows.  Ubuntu
is using NetworkManager, and I have defined the bridge there per
http://ask.xmodulo.com/configure-linux-bridge-network-manager-ubuntu.html.

This comes up as bridge0, and seems to be working just fine.  I then try
to start Debian-arm under qemu with:

qemu-system-arm -m 1024M \
	-sd /export/armhf.qcow2 \
	-M vexpress-a9 \
	-cpu cortex-a9 \
	-kernel /export/boot/vmlinuz \
	-initrd /export/boot/initrd.img \
	-append "root=/dev/mmcblk0p2" \
	-device virtio-net-device,netdev=net0 \
	-netdev bridge,br=bridge0,id=net0,helper=/usr/lib/qemu/qemu-bridge-helper

/etc/qemu/bridge.conf has

allow bridge0

Qemu starts just fine, no network-related errors, but no network
interface (eth0, etc.) in Debian.  Removing these lines and using slirp
and Debian gets an interface just fine.

Any suggestions as to where to look?  Again, I'm a programmer, not a
Linux admin, so I'm a bit lost there.

Thanks,
Jerry