Hi,
On 18/02/2017 15:09, Andrea Bolognani wrote:
On Fri, 2017-02-17 at 15:56 +0100, Andrea Bolognani wrote:
> libvirt is picking GICv3 here because QEMU reports it as a
> viable emulated GIC; however, as I understand it the
> emulated GICv3 doesn't have MSI support, and without that
> PCIe can't work. If you manually switch to GICv2 you should
> be able to run the guest succesfully.
>
> We should find a way to detect whether the interrupt
> controller will support PCIe, and fall back to using
> virtio-mmio when it doesn't. Eric, any ideas about how we
> could achieve that?
Actually, we will probably want to do the opposite, eg. pick
GICv2 over GICv3 if the latter doesn't allow us to use PCIe.
Yes I think the easiest solution is to select the GICv2 + v2m combo to
get the MSI support. This depends on whether the limitations linked to
GICv2 usage are acceptable in your case (max 8 cpus for instance).
Thanks
Eric
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Andrea Bolognani / Red Hat / Virtualization