[Libvir] <model>e1000</model> - Specifying model in XML Configs

[Pau Garcia i Quiles]

Quoting "Richard W.M. Jones" <rjones at redhat.com>:

> On Mon, Apr 07, 2008 at 10:51:56PM +0100, Henri Cook wrote:
>> I just tried to port a few customers over to this libvirt setup i'm
>> hoping to run and I couldn't get their machines started because there's
>> no mechanism to specify a model in the XML!
>>
>> I know redhat have changed KVM's default driver to e1000, which I think
>> is the one I like the most and almost if not all of my VMs use. Ubuntu
>> haven't done that yet however!
>>
>> Is there a model directive in the latest version? In the works? Just so
>> I know which solution I should pursue (updating libvirt or harassing
>> ubuntu to change the default)
>
> There isn't a way to select the model, but there ought to be.  In KVM
> 64 the following NIC models are supported:
>
>   i82551 i82557b i82559er ne2k_pci pcnet rtl8139 e1000 virtio
>
> Part of the problem with implementing this will be validating the
> model (unless we just pass the model string directly to qemu which
> could lead to errors).  The documentation suggests running qemu with
> '-net nic,model=?' to list the models, and there is code in
> qemu/hw/pci.c to implement this, but it just doesn't work for me.
>
>   $ qemu-kvm -net nic,model=?
>
>   [ prints full help because of the missing hda parameter ]
>
>   $ qemu-kvm -net nic,model=? hda=/dev/null
>   open /dev/kvm: Permission denied
>   Could not initialize KVM, will disable KVM support
>   Warning: vlan 0 is not connected to host network
>   qemu: could not open disk image hda=/dev/null
>
>   $ qemu-kvm -net nic,model=? hda=/dev/zero
>   open /dev/kvm: Permission denied
>   Could not initialize KVM, will disable KVM support
>   Warning: vlan 0 is not connected to host network
>   qemu: could not open disk image hda=/dev/zero
>
>   $ touch /tmp/file
>   $ qemu-kvm -net nic,model=? hda=/tmp/file
>   open /dev/kvm: Permission denied
>   Could not initialize KVM, will disable KVM support
>   Warning: vlan 0 is not connected to host network
>   qemu: could not open disk image hda=/tmp/file
>
>   $ dd if=/dev/zero of=/tmp/file bs=1024 count=1024
>   1024+0 records in
>   1024+0 records out
>   1048576 bytes (1.0 MB) copied, 0.00765395 s, 137 MB/s
>   $ qemu-kvm -net nic,model=? hda=/tmp/file
>   open /dev/kvm: Permission denied
>   Could not initialize KVM, will disable KVM support
>   Warning: vlan 0 is not connected to host network
>   qemu: could not open disk image hda=/tmp/file

The same error happens in KVM and Qemu (not qemu-kvm) on Ubuntu. I'd  
say the problem belongs to Qemu, not to KVM.

-- 
Pau Garcia i Quiles
http://www.elpauer.org
(Due to my workload, I may need 10 days to answer)