KVM on POWER9 doesn't use the XIVE VP space optimally. This currently limits the number of VMs we can start to 127. Starting with the 128th one, KVM fails to create the XIVE or the XICS-on-XIVE device and we go through the fallback paths in QEMU.
The XICS error path still has an issue that prevents the guest to do interrupts, even after QEMU fell back on XICS emulation. This is fixed with patch 2. Patch 1 is just a _trivial_ improvement of the warning that gets emited when falling back to emulated IC. Feel free to apply it to 4.2 or even to drop it if you don't want it in 4.1. -- Greg --- Greg Kurz (2): spapr/irq: Inform the user when falling back to emulated IC xics/kvm: Fix fallback to emulated XICS hw/intc/xics_kvm.c | 11 ----------- hw/ppc/spapr_irq.c | 1 + 2 files changed, 1 insertion(+), 11 deletions(-)