[Qemu-devel] Re: KVM call agenda for Jan 26

[Alexander Graf]

On 26.01.2010, at 14:33, Daniel P. Berrange wrote:

> On Tue, Jan 26, 2010 at 03:24:50PM +0200, Avi Kivity wrote:
>> On 01/26/2010 03:18 PM, Alexander Graf wrote:
>>> 
>>> The main question is where does it belong?
>>> 
>>> a) built into qemu
>>> b) built as separate tool, but shipped with qemu
>>> c) completely separate
>>> 
>>> I'm personally leaning towards a. That way we can reuse the detection code 
>>> and give help when an option is used that doesn't work.
>>> 
>>> 
>> 
>> Me too, especially as the whole stack is involved, and qemu is the 
>> topmost part from our perspective (no doubt libvirt will want to 
>> integrate that functionality as well).
> 
> FYI, libvirt already exposes this kind of functionality. The API call
> virConnectGetCapabilities() / command line "virsh capabilities" command
> tells you about what the virtualization host is able to support. It can
> tell you what architectures are supported, by which binaries. What
> machine types are available. Whether KVM or KQEMU acceleration are
> present. What CPU model / flags are on the host. What NUMA topology is
> available. etc etc 
> 
> The data format it outputs though is not exactly targetted for direct
> end user consumption though, rather its a XML doc aimed at applications
> The virt-manager app tries to use this to inform the user of problems
> such as ability todo hardware virt, but it not being enabled.

Hrm, while I sympathize with the goals of libvirt and all the efforts in it, 
I'd like to see the stock qemu exectable stay as user friendly as possible. One 
of qemu's strong points always used to be its really simple CLI.
So IMHO it rather belongs there with libvirt querying qemu than the other way 
around.

Nevertheless, I suppose the code would be a pretty good starting point!

Alex