[SOLVED] Qemu with host networking space.

Question

Hello, I'm trying to lunch Qemu with host networking, so the VM's can talk to each other, what I did so far is creating the following bridges ( Actually virt-manager did that for me ):
br0, virbr0 -> virbr0-nic ( the interface )
and have the following network interfaces:
br0, lo, virbr0, wlp1s0
What I think I'm missing is something on the code... I'm lunching with:
qemu-system-x86 -kernel kernel -cpu host -m 2024 -hda image.image
I did review the following manuals
https://wiki.archlinux.org/index.php/QE … networking
https://wiki.archlinux.org/index.php/Network_bridge
I'm missing the right command, thanks.
Last edited by abdullah (2015-02-06 18:00:11)

Answer 1

abdullah wrote:
Well, still trying, here is the code that I'm using right now:
./start.sh
#!/bin/bash
bridge=br0
tap=$(sudo tunctl -u $(whoami) -b)
sudo ip link set $tap up
sleep 1s
sudo brctl addif $bridge $tap
qemu-system ..... etc \
-net nic,vlan0,model=virtio,macaddr=00:16:35:AF:94:4B \
-net nic,vlan=0,ifname=$tap,script=no,downscript=no
sudo brctl delif $bridge $tap
sudo ip link set $tap down
sudo tunctl -d $tap
which the reff was in https://activedoc.opensuse.org/book/ope … h-qemu-kvm
any help please?
Sorry if I am late to the party... but here's how I do this with bridged networking.
Let's assume that I have 2 guests, an ArchLinux and Window 7. These are the start scripts:
: cat start-arch.sh
#!/bin/bash
vm_dir="/export/scratch/VMs"
scripts_dir="${vm_dir}/scripts"
. ${scripts_dir}/macaddr-gen.sh
# Generate a random MAC address
gen_macaddr mac
# Start the emulator
qemu-system-x86_64 -enable-kvm -smp 2 \
-net bridge,br=br0 -net nic,macaddr=${mac},model=virtio \
-drive file="${vm_dir}/arch-x86_64-1",if=virtio -nographic
: cat start-win7.sh
#!/bin/bash
vm_dir="/export/scratch/VMs"
scripts_dir="${vm_dir}/scripts"
. ${scripts_dir}/macaddr-gen.sh
# Generate a random MAC address
gen_macaddr mac
# Start the emulator
qemu-system-x86_64 -enable-kvm -m 3G -smp 2 \
-net bridge,br=br0 -net nic,macaddr=${mac},model=virtio \
-drive file="${vm_dir}/win7-x86_64-1",if=virtio \
-usbdevice tablet -vga qxl -spice port=5930,disable-ticketing
: cat macaddr-gen.sh
#!/bin/bash
# Generate a random MAC address
gen_macaddr() {
local str i macaddr _mac=$1
str=$(cat /dev/random | tr -cd '[:xdigit:]' | head -c 12 | \
tr '[:upper:]' '[:lower:]')
i=0
macaddr=""
while [ $i -lt 6 ]; do
macaddr=${macaddr}${str:0:2}":"
str=${str:2}
let i=i+1
done
eval $_mac=\${macaddr%:}
: cat /etc/qemu/bridge.conf
allow br0
Note, that the MAC addresses of virtualized NICs in the VMs must be different. If you now do
: ./start-arch.sh &
: ./start-win7.sh
Assuming that you have already set up  a bridge br0, qemu will create several tap? interfaces and insert them into that bridge (using the qemu-bridge-helper suid binary), and you'll have a virtual LAN rooted at br0.
EDIT: Added a slightly faster random MAC generator and comments.
Last edited by Leonid.I (2015-02-09 20:13:50)