On Fri, 2020-12-04 at 15:24 -0800, Sean Christopherson wrote:
> On Fri, Nov 20, 2020, Rick Edgecombe wrote:
> > +struct perm_allocation {
> > + struct page **pages;
> > + virtual_perm cur_perm;
> > + virtual_perm orig_perm;
> > + struct vm_struct *area;
> > + unsigned long offset;
> > + unsigned long size;
> > + void *writable;
> > +};
> > +
> > +/*
> > + * Allocate a special permission kva region. The region may not be
> > mapped
> > + * until a call to perm_writable_finish(). A writable region will
> > be mapped
> > + * immediately at the address returned by perm_writable_addr().
> > The allocation
> > + * will be made between the start and end virtual addresses.
> > + */
> > +struct perm_allocation *perm_alloc(unsigned long vstart, unsigned
> > long vend, unsigned long page_cnt,
> > + virtual_perm perms);
>
> IMO, 'perm' as the root namespace is too generic, and perm_ is
> already very
> prevelant throughout the kernel. E.g. it's not obvious when looking
> at the
> callers that perm_alloc() is the first step in setting up an
> alternate kernel
> VA->PA mapping.
>
> I don't have a suggestion for a more intuitive name, but in the
> absence of a
> perfect name, I'd vote for an acronym that is easy to
> grep. Something like
> pvmap? That isn't currently used in the kernel, though I can't help
> but read it
> as "paravirt map"...
Good point, thanks.
After Christoph's comments to return a vm_struct pointer, I was going
to try to pick some more vmalloc-like names. Like vmalloc_perm(),
vmalloc_writable_finish(), etc. Still have to play around with it some
more.
