Re: [PATCH v2 03/26] iommu/amd: Detect and initialize AMD vIOMMU feature

[Suthikulpanit, Suravee]

On 6/1/2026 7:43 PM, Jason Gunthorpe wrote:
> On Thu, May 28, 2026 at 05:17:15AM +0000, Suravee Suthikulpanit wrote:
> > The feature is advertised w/ EFR[VIOMMUSup]. Please see the AMD IOMMU
> > specification[1] for more detail.
> >
> > Introduce a new global variable amd_iommu_viommu, which is used to
> > control the feature enablement in the driver. Currently, the feature
> > is default to disabled. Once the feature is fully supported, it will be
> > changed to enabled by default along with a command-line option to disable
> > if needed.
>
> Still no to command line option. Just don't use iommufd if you don't
> want to use it. It must have no cost until iommufd activates it.
>
> Jason

Noted. Just do not set CONFIG_AMD_IOMMU_IOMMUFD to remove viommu support.

Suravee