On Tue, 2016-01-05 at 13:08 +0100, Christoffer Dall wrote:
On Mon, 2015-12-21 at 12:03 +0100, Christoffer Dall wrote:
So let me summarize the things we need to do: - patch libvirt to allow <gic version='host' /> - patch libvirt to properly probe for GICv2 and GICv3 support - patch libvirt to generally handle virt-host-validate on ARM And that should be enough for other tools such as OpenStack with Nova to probe and create the VMs it wishes. Does that about capture it? Sounds about right. I can work on points 1) and 3) of your list on my own, but for point 2) we need QEMU to start probing the host for supported GIC versions and expose such information before libvirt can use it. Then of course higher level tools such as OpenStack will need to become aware of these new features in libvirt. I thought the virt-host-validate tool in libvirt should do the probing
On Tue, Jan 05, 2016 at 12:37:02PM +0100, Andrea Bolognani wrote: directly?
The tool is just a convenience for the administrator (and for higher level tools?), and it can't be where the validation happens for two reasons: - it doesn't take any argument, so it can't possibly know whether you're interested in running GICv2 or GICv3 guests - libvirt needs to check before running the guest anyway Probing inside QEMU means libvirt can just ask it instead of implementing the checks itself, which means less code duplication; more importantly, this prevents the possibility of the checks ever going out of sync.
If I misunderstood, how would you like QEMU to report this?
I'm not 100% sure about the best interface here (hopefully other people can weigh in) but I imagine there would be some sort of QMP command that lists the GIC versions supported by the QEMU binary, or some text in the output of 'qemu -help' that can be parsed to obtain such list.
Should it be the qemu binary directly or the script that Peter suggested?
I think it should be the QEMU binary, especially since I assume QEMU itself will want to error out if an unsupported GIC version is requested by the user - there's no guarantee QEMU will be called by libvirt, so it will have to check on its own. Cheers. -- Andrea Bolognani Software Engineer - Virtualization Team