Re: [PATCH v5 15/22] x86/virt/tdx: Allocate and set up PAMTs for TDMRs

[Xiaoyao Li]

On 6/28/2022 4:41 AM, Dave Hansen wrote:
> On 6/27/22 03:31, Kai Huang wrote:
> > > > +/* Page sizes supported by TDX */
> > > > +enum tdx_page_sz {
> > > > +	TDX_PG_4K,
> > > > +	TDX_PG_2M,
> > > > +	TDX_PG_1G,
> > > > +	TDX_PG_MAX,
> > > > +};
> > > Are these the same constants as the magic numbers in Kirill's
> > > try_accept_one()?
> > try_accept_once() uses 'enum pg_level' PG_LEVEL_{4K,2M,1G} directly.  They can
> > be used directly too, but 'enum pg_level' has more than we need here:
>
> I meant this:
>
> +       switch (level) {
> +       case PG_LEVEL_4K:
> +               page_size = 0;
> +               break;
>
> Because TDX_PG_4K==page_size==0, and for this:
>
> +       case PG_LEVEL_2M:
> +               page_size = 1;

here we can just do

	page_size = level - 1;

or
	
	tdx_page_level = level - 1;

yes, TDX's page level definition is one level smaller of Linux's definition.

> where TDX_PG_2M==page_size==1
>
> See?
>
> Are Kirill's magic 0/1/2 numbers the same as
>
> 	TDX_PG_4K,
> 	TDX_PG_2M,
> 	TDX_PG_1G,
>
> ?