On Fri, Oct 14, 2016 at 01:25:35PM +0200, Igor Mammedov wrote: > 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");
Suggestion for a follow-up patch: * Error message explaining how to set eim=on if the iommu is available * Error message explaining how to make sure the iommu is created, in case it was not even created. -- Eduardo