Re: [libvirt] [PATCH 2/2] HACK: qemu: aarch64: Use virtio-pci if user specifies PCI controller

On Thu, 2016-03-10 at 09:56 +0000, Daniel P. Berrange wrote: > So, I've just seen that QEMU has decided that as of QEMU 2.6, the virt > machine type will start to be versioned.  This is quite convenient I > think as it gives us a nice thing to hook on. ie we see a non-versioned > machine type of 'virt' then we use virtio-mmio addressing, however, if > we see a versioned virt-X.Y.Z machine type, then we can assume pci by > default. > > Since the long term plan for AArch64 is to use PCI for everything, this > gives us nice default behaviour from this point onwards, while not > breaking compatibility for existing early adopters. > > Of course people with "legacy" mmio-only guests will stll have a little > pain to run then on new QEMU, but honestly I think that's worth it since > it will avoid us long term pain in the world where aarch64 uses pci for > everything I think it's way too early to flip the switch and default to PCI addresses: my understanding is that guest OS support is expected to be spotty at best for at least a couple more years.