Re: [Qemu-devel] [PATCH v3 13/13] pc: require IRQ remapping and EIM if there could be x2APIC CPUs

["Radim Krčmář" <rkrcmar@redhat.com>]

2016-10-13 11:52+0200, Igor Mammedov:
> it would prevent starting guest with incorrect configs
> where interrupts couldn't be delivered to CPUs with
> APIC IDs > 254.

off-by-one.

> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---

Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>

>  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
> 
>