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

[Baolu Lu]

Hi Jason,

On 2022/5/17 02:06, Jason Gunthorpe wrote:
> > +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?

Good question. From IOMMU point of view, I don't see a point to force
ATS off, but trust boot involves lots of other things that I am not
familiar with. Anybody else could help to answer?

Best regards,
baolu