Re: [PATCH 0/5] libxc: support building large pv-domains

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

On Fri, 2015-09-11 at 14:32 +0200, Juergen Gross wrote:
> The Xen hypervisor supports starting a dom0 with large memory (up to
> the TB range) by not including the initrd and p2m list in the initial
> kernel mapping. Especially the p2m list can grow larger than the
> available virtual space in the initial mapping.
> 
> The started kernel is indicating the support of each feature via
> elf notes.
> 
> This series enables the domain builder in libxc to do the same as the
> hypervisor. This enables starting of huge pv-domUs via xl.
> 
> Unmapped initrd is supported for 64 and 32 bit domains, omitting the
> p2m from initial kernel mapping is possible for 64 bit domains only.
> 
> Tested with:
> - 32 bit domU (kernel not supporting unmapped initrd)
> - 32 bit domU (kernel supporting unmapped initrd)
> - 1 GB 64 bit domU (kernel supporting unmapped initrd, not p2m)
> - 1 GB 64 bit domU (kernel supporting unmapped initrd and p2m)
> - 900GB 64 bit domU (kernel supporting unmapped initrd and p2m)
> 
> Juergen Gross (5):
>   libxc: remove allocate member from struct xc_dom_image
>   libxc: do initrd processing of domain builder in own function
>   libxc: create unmapped initrd in domain builder if supported
>   libxc: split p2m allocation in domain builder from other magic pages
>   libxc: create p2m list outside of kernel mapping if supported
> 
>  tools/libxc/include/xc_dom.h |   4 +-
>  tools/libxc/xc_dom_core.c    | 123 +++++++++++++++++++++++++++++--------------
>  tools/libxc/xc_dom_x86.c     | 120 ++++++++++++++++++++++++++++++++++++++++-

How much is this going to conflict with Roger's "Introduce HVM without dm
and new boot ABI" changes to HVM building?

>  3 files changed, 204 insertions(+), 43 deletions(-)
>