Re: [Xen-ia64-devel] [PATCH][RFC][TAKE4] the P2M/VP patches

[Alex Williamson <alex.williamson@xxxxxx>]

On Mon, 2006-04-10 at 13:55 +0900, Isaku Yamahata wrote:
> I have the following ideas. I think B. or C. might be good.
> What do you think of them?
> 
> A. record a huge region to somewhere (maybe struct arch_domain) and
>    add region check code to lookup_domian_mpa() (and its families)
>    for special conversion on a huge region.
> 
> B. introduce a flag of super page for the P2M table.
>    Then only a PGD (, PUD and PMD )page is needed to map such a huge page.
>    Modify lookup_domain_mpa(), dom_fw_dom0_passthrough() and their families
>    to be aware of super page flag.
> 
> C. Don't map MMIO range at domain creation. But map it when ioremap hypercall.
>    Maybe only small portion of the range will be used.
> 
> D. other?

   Choice C might be a good idea from a simplicity and compactness
perspective.  It typically is the case that only a small portion of MMIO
is actually in use.  Maybe this could also facilitate driver domains as
MMIO ranges could be more dynamically allocated(?).  Thanks,

        Alex

-- 
Alex Williamson                             HP Linux & Open Source Lab


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