[Fedora-xen] Can't boot RH7.2 fully-virtualized guest

[Hanks, Dan]

> 
> Hanks, Dan wrote:
> > MXT page nr start=ffffffff len=ffffffff
> > Ooops! Too many entries in the memory map"
> > This ends in a kernel panic, complaining:
> > "<0> Kernel panic: Attempted to kill the idle task! In idle task -
not
> > syncing"
> 
> We ran into the same problem.  The default kernel for RH7.2 is patched
> to support "MXT" (automatic compression to/from RAM), and the HVM bios
> confuses it.
> 
> Upgrade the kernel to one that doesn't have MXT (such as
> kernel-smp-2.4.20-28.7) and you'll be fine.
> 
> There may also be a boot param to tell the kernel to ignore MXT, which
> would likely have the same effect.

Dr. Google indicated that setting mem=NNN in the kernel args effectively
disables MXT, however when I tried that, I got no kernel panics, but the
VM hung shortly after "Uncompressing the kernel"

So, I went out and snagged an old kernel SRPM for RH72 from the RedHat
archives, added one line to the spec file to swap CONFIG_MXT=y with
CONFIG_MXT=n in the kernel configs, rebuilt, mounted up the RH72 disk
image, chrooted to it, installed my new rpm in place of the existing
rpm, fired it up, and voila, it appears to be working.

Thanks much for your help, it pointed me in the right direction!

-- Dan