Re: Re: [PATCH] qemu-xen: Fix PV segfault

[Gerd Hoffmann <kraxel@redhat.com>]

Ian Jackson wrote:
> Gerd Hoffmann writes ("Re: [Xen-devel] Re: [PATCH] qemu-xen: Fix PV segfault"):
>> Looked at the qemu-xen tree and the branches therein today (missed the
>> original announcement as I was on vacation at that point in time).
>> Ian's plan seems to be to upstream mostly bugfixes (qemu branch), not
>> any xen-specific code.
> 
> I would like the xen code to go upstream as well eventually.  However
> upstream have said that they're not happy with some of the things
> which are essential in our tree.  For example, they are opposed to the
> mapcache, which is essential for decoupling guest addresses from
> qemu's address space (particularly since the guest maybe 64-bit and
> qemu only 32-bit!)

That doesn't mean we can't upstream any xen bits.  The whole pv domain
support doesn't need mapcache in the first place for example.

Didn't check how intrusive mapcache is, but would it be an option to
make it optional?  So upstream has most other bits, you have a much
smaller patch queue.

Also I'd expect that if you run guests that big that the 32bit address
space limits become problematic, wouldn't you run 64bit xen+dom0 anyway
for performance reasons?

cheers,
  Gerd

-- 
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