Re: [PATCH v2 3/4] mini-os: fix number of pages for PVH

[Juergen Gross <jgross@xxxxxxxx>]

On 21.06.22 00:43, Samuel Thibault wrote:
> Juergen Gross, le dim. 19 juin 2022 08:52:52 +0200, a ecrit:
> > When getting the current allocation from Xen, this value includes the
> > pages allocated in the MMIO area. Fix the highest available RAM page
> > by subtracting the size of that area.
> >
> > This requires to read the E820 map before needing this value. Add two
> > functions returning the current and the maximum number of RAM pages
> > taking this correction into account.
> >
> > At the same time add the LAPIC page to the memory map in order to
> > avoid reusing that PFN for internal purposes.
> >
> > Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > ---
> > V2:
> > - make e820_initial_reserved_pfns static (Samuel Thibault)
> > - add e820_get_current_pages() and e820_get_max_pages()
> > ---
> > diff --git a/include/e820.h b/include/e820.h
> > index 5438a7c8..6f15fcd2 100644
> > --- a/include/e820.h
> > +++ b/include/e820.h
> > @@ -52,6 +52,8 @@ struct __packed e820entry {
> >   extern struct e820entry e820_map[];
> >   extern unsigned e820_entries;
> >   
> > +unsigned int e820_get_current_pages(void);
> > +unsigned int e820_get_max_pages(void);
> Why an int rather than a long int? Yes 4TiB memory is large for mini-os,
> but better keep numbers of pages a long?
I don't think it matters that much (currently Mini-OS can't support more
than 512GiB of memory), but I can change the functions to unsigned long.

> Apart from that,
>
> Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
Thanks,


Juergen

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