Re: [RFC] libxc: Add trusted decompressors

[Bastian Blank <waldi@debian.org>]

On Wed, Feb 27, 2013 at 12:17:07PM +0000, Ian Campbell wrote:
> On Tue, 2013-02-26 at 22:32 +0000, Bastian Blank wrote:
> > Add trusted decompressors based on hypervisor code.
> > This are used in mini-os by pv-grub.
> I think this is a reasonably pragmatic way to arrange the build.

What should be fixed later:
- Use standard types in the decompressors (this both extends compiler
  support and portability)
- Remove stuff like always_inline (the compiler almost always knows
  better these days)

What should be done now:
- Drop bzip2 and lzma decoders. I have never seen bzip2 used anywhere
  because it is slow and lzma is replaced entirely by xz.
- Fix the arch detection for the xz bcj decoders.

> I'm not sure "trusted" is quite the right term though, these aren't
> really any more trustworthy than the library supplied ones -- they are
> just more suitable for a mini-os environment.

I used the term "trusted" because it should not be fed with untrusted
input. So it should not be used in the normal libxenguest. In the case
of pv-grub, all input is trusted as it runs in the same security domain.

Bastian

-- 
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