Re: [Xen-devel] [PATCH v6 04/18] vt-d: VT-d Posted-Interrupts feature detection

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 25.08.15 at 03:57, <feng.wu@xxxxxxxxx> wrote:
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -2079,6 +2079,9 @@ static int init_vtd_hw(void)
>                  disable_intremap(drhd->iommu);
>      }
>  
> +    if ( !iommu_intremap )
> +        iommu_intpost = 0;

Why is this being repeated here? iommu_setup() is already taking
care of this thanks to the earlier patch.

> @@ -2176,6 +2179,14 @@ int __init intel_vtd_setup(void)
>          if ( iommu_intremap && !ecap_intr_remap(iommu->ecap) )
>              iommu_intremap = 0;
>  
> +        /*
> +         * We cannot use posted interrupt if X86_FEATURE_CX16 is
> +         * not supported, since we count on this feature to
> +         * atomically update 16-byte IRTE in posted format.
> +         */
> +        if ( !iommu_intremap || !cap_intr_post(iommu->cap) || !cpu_has_cx16 )
> +            iommu_intpost = 0;

You should check iommu_intpost instead of iommu_intremap to
match the other checks above here.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel