Re: [PATCH] x86/arm/mm: use gfn instead of pfn in p2m_get_mem_access/p2m_set_mem_access

[Ian Campbell <ian.campbell@citrix.com>]

On Tue, 2015-06-23 at 18:25 +0200, Vitaly Kuznetsov wrote:
> "Jan Beulich" <JBeulich@suse.com> writes:
> 
> >>>> On 26.05.15 at 15:32, <vkuznets@redhat.com> wrote:
> >> --- a/xen/arch/arm/p2m.c
> >> +++ b/xen/arch/arm/p2m.c
> >> @@ -1709,9 +1709,9 @@ bool_t p2m_mem_access_check(paddr_t gpa, vaddr_t gla, 
> >> const struct npfec npfec)
> >>  
> >>  /*
> >>   * Set access type for a region of pfns.
> >> - * If start_pfn == -1ul, sets the default access type.
> >> + * If start_gfn == -1ul, sets the default access type.
> >>   */
> >> -long p2m_set_mem_access(struct domain *d, unsigned long pfn, uint32_t nr,
> >> +long p2m_set_mem_access(struct domain *d, unsigned long start_gfn, uint32_t nr,
> >>                          uint32_t start, uint32_t mask, xenmem_access_t access)
> >>  {
> >>      struct p2m_domain *p2m = p2m_get_hostp2m(d);
> >> @@ -1752,14 +1752,15 @@ long p2m_set_mem_access(struct domain *d, unsigned long pfn, uint32_t nr,
> >>      p2m->mem_access_enabled = true;
> >>  
> >>      /* If request to set default access. */
> >> -    if ( pfn == ~0ul )
> >> +    if ( start_gfn == ~0ul )
> >>      {
> >>          p2m->default_access = a;
> >>          return 0;
> >>      }
> >>  
> >>      rc = apply_p2m_changes(d, MEMACCESS,
> >> -                           pfn_to_paddr(pfn+start), pfn_to_paddr(pfn+nr),
> >> +                           pfn_to_paddr(start_gfn + start),
> >
> > Particularly due to this expression I'm not really happy about the
> > start_ prefix that you're adding here, but I'll let the maintainers
> > of the respective pieces of code decide if they're happy with it.
> 
> Sorry for the ping but it has been almost one month...

Sorry, I must have missed this one, pinging was absolutely the right
thing to do (after a week or two would have been fine, no need to wait a
month).

I'm not super keen on the start_ prefix either, but I would prefer
consistency between arm and x86 here more than I object to the prefix.
IOW my preference would be to drop it everywhere, but if x86 folks
prefer to keep it then I don't mind but ARM should keep it too.

I've also copied the (new) mem access maintainers in case they have an
opinion.

Ian.