if VM is started with: -enable-kvm -smp 256
without specifying 'split' irqchip, VM might eventually boot but no more than 255 CPUs will be operational and following error messages in guest could be observed: ... smpboot: native_cpu_up: bad cpu 256 ... It's a regression introduced by [1], which removed dependency on intremap=on that were implicitly requiring 'split' irqchip and forgot to check for 'split' irqchip. Instead of letting VM boot a broken VM, error out and tell user how to fix CLI. Fixes: c1bb5418e ("target/i386: Support up to 32768 CPUs without IRQ remapping") Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2060691 Signed-off-by: Igor Mammedov <imamm...@redhat.com> --- hw/i386/pc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index fd55fc725c..a612df5241 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -743,9 +743,9 @@ void pc_machine_done(Notifier *notifier, void *data) if (x86ms->apic_id_limit > 255 && !xen_enabled() && - !kvm_irqchip_in_kernel()) { - error_report("current -smp configuration requires kernel " - "irqchip support."); + !kvm_irqchip_is_split()) { + error_report("current -smp configuration requires 'split' irqchip," + "ensure that '-machine kernel-irqchip=split' is used."); exit(EXIT_FAILURE); } } -- 2.31.1