We've had discussions before about the various limits in the virt board imposed by its current address space layout: * number of CPUs limited to 123 (not enough space for more redistributors) * number of PCIe devices limited by size of ECAM space * max memory size limits * (anything else?)
If we want to try to fix these this release cycle now would be a good point to figure out our approach so that we have plenty of time to do it in. (Relatedly, I notice patches on list for kvm that allow userspace to set the guest physical address size, which may affect how we want to do this.) I'm not going to have time to look at this but am happy to provide my opinions on whatever proposals other people would like to suggest. Probably the first thing to do is figure out whether we can raise these limits without having to have a flag day (ie just with changing the device tree we provide the guest), or if we really have a hard compat break here. We should also try to fix all these things at once rather than potentially breaking guests several times... thanks -- PMM
