> From: James Morse <james.morse@xxxxxxx> > Sent: Wednesday, September 13, 2023 5:38 PM [...] > > Hello! > > Changes since RFC-v1: > * riscv is new, ia64 is gone > * The KVM support is different, and upstream - no need to patch the host. > > --- > > This series adds what looks like cpuhotplug support to arm64 for use in > virtual machines. It does this by moving the cpu_register() calls for > architectures that support ACPI out of the arch code by using > GENERIC_CPU_DEVICES, then into the ACPI processor driver. > > The kubernetes folk really want to be able to add CPUs to an existing VM, > in exactly the same way they do on x86. The use-case is pre-booting guests > with one CPU, then adding the number that were actually needed when the > workload is provisioned. > [...] > > I had a go at switching the remaining architectures over to > GENERIC_CPU_DEVICES, > so that the Kconfig symbol can be removed, but I got stuck with powerpc > and s390. > > I've only build tested Loongarch and riscv. I've removed the ia64 specific > patches, but left the changes in other patches to make git-grep review of > renames easier. > > If folk want to play along at home, you'll need a copy of Qemu that > supports this. > https://github.com/salil-mehta/qemu.git salil/virt-cpuhp-armv8/rfc-v2-rc6 Please use the latest pushed RFC V2 instead: https://lore.kernel.org/qemu-devel/20230926100436.28284-1-salil.mehta@xxxxxxxxxx/T/#m523b37819c4811c7827333982004e07a1ef03879 Repository: https://github.com/salil-mehta/qemu.git virt-cpuhp-armv8/rfc-v2 Thanks Salil. [...] > Why is this still an RFC? I'm still looking for confirmation from the > kubernetes/kata folk that this works for them. Because of this I've culled > the CC list... > > > This series is based on v6.6-rc1, and can be retrieved from: > https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/virtual_cpu_hotplug/rfc/v2