Hi everyone, I have recently learned about the on-going work from David Hildenbrand about virtio-mem, with a strong focus on proposing a unified solution for every architecture, which is the point of using paravirtualization here. This proposes a standardized way across different hypervisors to manage the guest RAM available, which at the same time will allow for a clean memory hot(un)plug support. Based on this, I was thinking that once this will be ready, and assuming you manage your devices through a PCI bus, the last bit to get rid of ACPI dependency would be about CPU. We could standardize the way vCPUs are created and managed by each hypervisors by introducing virtio-cpu. And the same way I mentioned architecture agnostic and clean hotplug for virtio-mem, I would expect this new virtio device to target the same goals. The end goal is to propose an approach where hypervisors could be unified across architectures, which would be convenient to support CPU hotplug features, without being forced to use ACPI only for this purpose. I am really looking for community's feedback here, as I would like to understand if there are some technical reasons why this approach would not be feasible/acceptable. Also, please let me know if there is already some on-going work, I'd be happy to participate! Thanks, Sebastien
