Re: [Qemu-devel] [PATCH v2 5/7] intel-iommu: add OnOffAuto intr_eim as "eim" property

[Peter Xu <peterx@redhat.com>]

On Thu, Sep 29, 2016 at 01:23:27PM +0200, Radim Krčmář wrote:
> The default (auto) emulates the current behavior.
> 
> Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
> ---
>  hw/i386/intel_iommu.c         | 20 +++++++++++++++++++-
>  include/hw/i386/intel_iommu.h |  1 +
>  2 files changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index eb488c14625d..47141cea64f4 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2011,6 +2011,8 @@ static const MemoryRegionOps vtd_mem_ops = {
>  
>  static Property vtd_properties[] = {
>      DEFINE_PROP_UINT32("version", IntelIOMMUState, version, 0),
> +    DEFINE_PROP_ON_OFF_AUTO("eim", IntelIOMMUState, intr_eim,
> +                            ON_OFF_AUTO_AUTO),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -2367,7 +2369,11 @@ static void vtd_init(IntelIOMMUState *s)
>      s->ecap = VTD_ECAP_QI | VTD_ECAP_IRO;
>  
>      if (x86_iommu->intr_supported) {
> -        s->ecap |= VTD_ECAP_IR | VTD_ECAP_EIM | VTD_ECAP_MHMV;
> +        s->ecap |= VTD_ECAP_IR | VTD_ECAP_MHMV;
> +        if (s->intr_eim == ON_OFF_AUTO_ON) {
> +            s->ecap |= VTD_ECAP_EIM;
> +        }
> +        assert(s->intr_eim != ON_OFF_AUTO_AUTO);
>      }
>  
>      vtd_reset_context_cache(s);
> @@ -2466,6 +2472,18 @@ static void vtd_realize(DeviceState *dev, Error **errp)
>          exit(1);
>      }
>  
> +    if (s->intr_eim == ON_OFF_AUTO_ON && !x86_iommu->intr_supported) {
> +        error_report("intel-iommu,eim=on cannot be selected without "
> +                     "intremap=on.");
> +        exit(1);
> +    }
> +    if (s->intr_eim == ON_OFF_AUTO_AUTO && !x86_iommu->intr_supported) {
> +        s->intr_eim = ON_OFF_AUTO_OFF;
> +    }
> +    if (s->intr_eim == ON_OFF_AUTO_AUTO) {
> +        s->intr_eim = ON_OFF_AUTO_ON;
> +    }

A single if() instead of above two might be nicer:

    if (s->intr_eim == ON_OFF_AUTO_AUTO) {
        e->intr_eim = x86_iommu->intr_supported ?
            ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
    }

Otherwise good to me.

Thanks,

-- peterx