Re: [PATCH v5 12/15] iommupt: Add the x86 64 bit page table format

Jason Gunthorpe
2025-09-29T16:17:29Z

On Fri, Sep 26, 2025 at 07:57:07AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Thursday, September 4, 2025 1:47 AM
> >
> > +#define PT_FMT x86_64
> > +#define PT_SUPPORTED_FEATURES \
> > + (BIT(PT_FEAT_SIGN_EXTEND) | BIT(PT_FEAT_FLUSH_RANGE) | \
> > + BIT(PT_FEAT_FLUSH_RANGE_NO_GAPS) | \
> > + BIT(PT_FEAT_X86_64_AMD_ENCRYPT_TABLES))
> > +
>
> iirc we discussed that FLUSH_RANGE and FLUSH_RANGE_NO_GAPS are
> mutually exclusive. so it's a typo to set both of them here?

They cannot be enabled together, but this is SUPPORTED_FEATURES, so
the built .ko can support using both. In the case of VTD the instance
cap drives which of FLUSH_RANGE / NO_GAPS is selected for the entire
instance.

Jason