libvirt users - Apr 2019 - Guest interface names not same as configured name

Hi,

I am creating a guest with following description for interfaces in the xml
using virsh create xml command. For some reason, the guest interface names
in the VM dont match the names specified in the xml. Is there a way to make
guest interface names predictable?

Following is the qemu version on host

dpkg --list | grep -i qemu
ii  qemu-kvm                              1:2.11+dfsg-1ubuntu7.10
      amd64        QEMU Full virtualization on x86 hardware

    <interface type='user'>
      <mac address='52:54:00:17:0b:e7'/>
      <guest dev='eth0'/>
      <model type='e1000'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x03'
function='0x0'/>
    </interface>
    <interface type='ethernet'>
      <mac address='52:54:00:ee:70:34'/>
      <target dev='net0'/>
      <guest dev='Ethernet0'/>
      <model type='rtl8139'/>
      <alias name='net1'/>
      <address type='pci' domain='0x0000' bus='0x00'
slot='0x05'
function='0x0'/>
    </interface>

Thanks

On 4/4/19 2:02 PM, PR PR wrote:
> Hi,
> 
> I am creating a guest with following description for interfaces in the 
> xml using virsh create xml command. For some reason, the guest interface 
> names in the VM dont match the names specified in the xml. Is there a 
> way to make guest interface names predictable?
For qemu (which you've indicating you're using) there isn't any way
to
set the name of the network device in the guest from the libvirt config. 
There is no visibility of the <guest dev='xxx'> element into the
guest
OS; all that the guest can know is that there is an e1000 ethernet 
device plugged into PCI bus 0 slot 3, and it has MAC address 
52:54:00:17:0b:e7. Any determination of name must be done within the 
guest OS.

The <guest dev='blah'> element is only used by the LXC and openvz 
drivers. It really should be flagged as an error during validation for 
other drivers (patches welcome :-).

> 
> Following is the qemu version on host
> 
> dpkg --list | grep -i qemu
> ii  qemu-kvm                              1:2.11+dfsg-1ubuntu7.10        
>          amd64        QEMU Full virtualization on x86 hardware
> 
>      <interface type='user'>
>        <mac address='52:54:00:17:0b:e7'/>
>        <guest dev='eth0'/>
>        <model type='e1000'/>
>        <alias name='net0'/>
>        <address type='pci' domain='0x0000'
bus='0x00' slot='0x03'
> function='0x0'/>
>      </interface>
>      <interface type='ethernet'>
>        <mac address='52:54:00:ee:70:34'/>
>        <target dev='net0'/>
>        <guest dev='Ethernet0'/>
>        <model type='rtl8139'/>
>        <alias name='net1'/>
>        <address type='pci' domain='0x0000'
bus='0x00' slot='0x05'
> function='0x0'/>
>      </interface>
> 
> Thanks
> 
> _______________________________________________
> libvirt-users mailing list
> libvirt-users@redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
>

Thanks for the quick response. I was able to use udev to control the names
in the guest. Reg patch, i am new to this codebase and sure if you give me
pointers on which file to look into I can give it a shot.

Thanks

On Thu, Apr 4, 2019 at 2:35 PM Laine Stump <laine@redhat.com> wrote:
> On 4/4/19 2:02 PM, PR PR wrote:
> > Hi,
> >
> > I am creating a guest with following description for interfaces in the
> > xml using virsh create xml command. For some reason, the guest
interface
> > names in the VM dont match the names specified in the xml. Is there a
> > way to make guest interface names predictable?
>
> For qemu (which you've indicating you're using) there isn't any
way to
> set the name of the network device in the guest from the libvirt config.
> There is no visibility of the <guest dev='xxx'> element into
the guest
> OS; all that the guest can know is that there is an e1000 ethernet
> device plugged into PCI bus 0 slot 3, and it has MAC address
> 52:54:00:17:0b:e7. Any determination of name must be done within the
> guest OS.
>
> The <guest dev='blah'> element is only used by the LXC and
openvz
> drivers. It really should be flagged as an error during validation for
> other drivers (patches welcome :-).
>
>
> >
> > Following is the qemu version on host
> >
> > dpkg --list | grep -i qemu
> > ii  qemu-kvm                              1:2.11+dfsg-1ubuntu7.10
> >          amd64        QEMU Full virtualization on x86 hardware
> >
> >      <interface type='user'>
> >        <mac address='52:54:00:17:0b:e7'/>
> >        <guest dev='eth0'/>
> >        <model type='e1000'/>
> >        <alias name='net0'/>
> >        <address type='pci' domain='0x0000'
bus='0x00' slot='0x03'
> > function='0x0'/>
> >      </interface>
> >      <interface type='ethernet'>
> >        <mac address='52:54:00:ee:70:34'/>
> >        <target dev='net0'/>
> >        <guest dev='Ethernet0'/>
> >        <model type='rtl8139'/>
> >        <alias name='net1'/>
> >        <address type='pci' domain='0x0000'
bus='0x00' slot='0x05'
> > function='0x0'/>
> >      </interface>
> >
> > Thanks
> >
> > _______________________________________________
> > libvirt-users mailing list
> > libvirt-users@redhat.com
> > https://www.redhat.com/mailman/listinfo/libvirt-users
> >
>
>