Re: [PATCH 6/7] x86/boot/tboot: Move tboot_force_iommu() to Intel IOMMU

[Jason Gunthorpe]

On Sat, May 14, 2022 at 09:43:21AM +0800, Lu Baolu wrote:
> tboot_force_iommu() is only called by the Intel IOMMU driver. Move the
> helper into that driver. No functional change intended.
> 
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---
>  include/linux/tboot.h       |  2 --
>  arch/x86/kernel/tboot.c     | 15 ---------------
>  drivers/iommu/intel/iommu.c | 14 ++++++++++++++
>  3 files changed, 14 insertions(+), 17 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>

> +static __init int tboot_force_iommu(void)
> +{
> +	if (!tboot_enabled())
> +		return 0;
> +
> +	if (no_iommu || dmar_disabled)
> +		pr_warn("Forcing Intel-IOMMU to enabled\n");

Unrelated, but when we are in the special secure IOMMU modes, do we
force ATS off? Specifically does the IOMMU reject TLPs that are marked
as translated?

Jason