On Fri, Jun 15, 2018 at 03:31:57PM +0000, Dave Hansen wrote: > On 06/15/2018 08:27 AM, Kirill A. Shutemov wrote: > > On Fri, Jun 15, 2018 at 01:43:03PM +0000, Dave Hansen wrote: > >> On 06/15/2018 05:57 AM, Kirill A. Shutemov wrote: > >>>>> +#define _PAGE_CHG_MASK (PTE_PFN_MASK_MAX | _PAGE_PCD | _PAGE_PWT | \ > >>>>> _PAGE_SPECIAL | _PAGE_ACCESSED | _PAGE_DIRTY | \ > >>>>> _PAGE_SOFT_DIRTY) > >>>>> #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE) > >>>> This makes me a bit nervous. We have some places (here) where we > >>>> pretend that the KeyID is part of the paddr and then other places like > >>>> pte_pfn() where it's not. > >>> Other option is to include KeyID mask into _PAGE_CHG_MASK. But it means > >>> _PAGE_CHG_MASK would need to reference *two* variables: physical_mask and > >>> mktme_keyid_mask. I mentioned this in the commit message. > >> > >> Why can't it be one variable with a different name that's populated by > >> OR'ing physical_mask and mktme_keyid_mask together? > > > > My point is that we don't need variables at all here. > > > > Architecture defines range of bits in PTE used for PFN. MKTME reduces the > > number of bits for PFN. PTE_PFN_MASK_MAX represents the original > > architectural range, before MKTME stole these bits. > > > > PTE_PFN_MASK_MAX is constant -- on x86-64 bits 51:12 -- regardless of > > MKTME support. > > Then please just rename the make PTE_<SOMETHING>_MASK where <SOMETHING> > includes both the concept of a physical address and a MKTME keyID. Just > don't call it a pfn if it is not used in physical addressing. I have no idea what such concept should be called. I cannot come with anything better than PTE_PFN_MASK_MAX. Do you? -- Kirill A. Shutemov
