Re: [PART2 RFC v1 1/9] iommu/amd: Detect and enable guest vAPIC support

[Joerg Roedel]

On Fri, Apr 08, 2016 at 07:49:22AM -0500, Suthikulpanit, Suravee wrote:
> From: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
> 
> This patch introduces a new IOMMU driver parameter, amd_iommu_guest_ir,
> which can be used to specify different interrupt remapping mode for
> passthrough devices to VM guest:
>     * legacy: Legacy interrupt remapping mode (w/ 32-bit IRTE)
>     * ga    : Guest vAPIC interrupt remapping mode (w/ 128-bit IRTE)
> 
> Note that the GA mode also supports legacy interrupt remapping
> for non-passthrough devices with the 128-bit IRTE.

Does this need to be under user control? The code can just check what
the hardware supports and use the 128bit IRTEs if supported, no?



	Joerg