Re: [Qemu-devel] [PATCH 03/23] PPC: Add CPU definitions for up to 32 guest CPUs

[Scott Wood]

On Thu, 21 Jul 2011 03:27:14 +0200
Alexander Graf <address@hidden> wrote:

> All guest CPUs need to be specified in the device trees. Since removing nodes
> is easy with FDT, but adding nodes is not, we just put 32 CPU nodes into the
> device tree and remove them later on init when not used.

Adding nodes isn't that hard...

I'm also hesitant to stick so many CPUs on something modeled after an
e500v2-era mpc85xx.  E.g. in the MPIC the upper bits of xIDR are used
for EP/CIx.  The newer MPIC used in p4080 and such move crit/mcheck routing
into a separate register.  There are similar constraints in guts (power
management), and possibly elsewhere.

-Scott