[virt-tools-list] [PATCH v2 3/3] Add support for cpu host-passthrough mode

[Guannan Ren]

On 04/15/2013 01:45 AM, Cole Robinson wrote:
>
> So here I'm not sure we even want host-passthrough in the virt-manager UI. I
> know it's valuable and useful, but there's the problem that libvirt 'taints'
> the VM when you set this flag. This doesn't really have any functional effect,
> but it basically means that libvirt devs consider this option to be not all
> that supportable. Exposing it in the UI seems like going against libvirt's wishes.
>
> It's also quite hard to explain host-model vs host-passthrough to an end user.
> We could just throw them in a combo box, but I guarantee it will have people
> asking over and over what the difference between host-model and
> host-passthrough is.
>
> I'm fine with allowing this via virt-install though.
>
> I'm not sure what the end result UI should be here. If we use host-model when
> libvirt is new enough, the current UI doesn't quite fit, because we don't know
> what libvirt cpu model and feature flags we are going to get until we define
> the VM, so hitting the 'copy' button won't update the UI. I guess we could
> change it to a checkbox.

           Yes, checkbox is good for using host-model.
           Currently, after clicking 'copy' button, the user still could 
be able to
           add/remove features or even change cpu model based on host cpu
           configuration further before applying. After we change it to 
a checkbox,
           The part of the functionality will lose, but user could still 
get what
           they want by using custom mode.


>
> Also, I don't know if host-model allows add/removing extra CPU flags, so if
> host-model is selected, we might want to disable the feature list and model
> drop down to make it clear they aren't editable. They should still be viewable
> though so users can see the exact configuration.


           libvirt will ignore the xml definition of extra feature flags 
in the case of host-model.
           Okay, I will modify some of my patches for the above.
           Thanks.

           Guannan