it would prevent starting guest with incorrect configs where interrupts couldn't be delivered to CPUs with APIC IDs > 255.
Signed-off-by: Igor Mammedov <imamm...@redhat.com> Reviewed-by: Radim Krčmář <rkrc...@redhat.com> --- v4: - s/254/255/ in commit message (Radim) --- hw/i386/pc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index 40eb43b..f7070e0 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -68,6 +68,7 @@ #include "qapi-visit.h" #include "qom/cpu.h" #include "hw/nmi.h" +#include "hw/i386/intel_iommu.h" /* debug PC/ISA interrupts */ //#define DEBUG_IRQ @@ -1264,6 +1265,18 @@ void pc_machine_done(Notifier *notifier, void *data) sizeof(pcms->boot_cpus_le)); } } + + if (pcms->apic_id_limit > 255) { + IntelIOMMUState *iommu = INTEL_IOMMU_DEVICE(x86_iommu_get_default()); + + if (!iommu || !iommu->x86_iommu.intr_supported || + iommu->intr_eim != ON_OFF_AUTO_ON) { + error_report("current -smp configuration requires " + "Extended Interrupt Mode enabled. " + "IOMMU should have eim=on option set"); + exit(EXIT_FAILURE); + } + } } void pc_guest_info_init(PCMachineState *pcms) -- 2.7.4