Re: [PATCH] libelf: improve PVH elfnote parsing

[Jason Andryuk <jandryuk@xxxxxxxxx>]

On Fri, May 14, 2021 at 9:50 AM Roger Pau Monne <roger.pau@xxxxxxxxxx> wrote:
>
> Pass an hvm boolean parameter to the elf note parsing and checking
> routines, so that better checking can be done in case libelf is
> dealing with an hvm container.
>
> elf_xen_note_check shouldn't return early unless PHYS32_ENTRY is set
> and the container is of type HVM, or else the loader and version
> checks would be avoided for kernels intended to be booted as PV but
> that also have PHYS32_ENTRY set.
>
> Adjust elf_xen_addr_calc_check so that the virtual addresses are
> actually physical ones (by setting virt_base and elf_paddr_offset to
> zero) when the container is of type HVM, as that container is always
> started with paging disabled.

Should elf_xen_addr_calc_check be changed so that PV operates on
virtual addresses and HVM operates on physical addresses?

I worked on some patches for this a while back, but lost track when
other work pulled me away.  I'll send out what I had, but I think I
had not tested many of the cases.  Also, I had other questions about
the approach.  Fundamentally, what notes and limits need to be checked
for PVH vs. PV?

Regards,
Jason