new cpu affinity syscalls and (k)qemu on amd64 SMP

[Juergen Lock]

Hi!

 There's a (remote?) possibility that the amd64 SMP kqemu crashes
could be cured by pinning the qemu process to a single cpu (tho, if its
that, I wonder why it works on i386 without doing that...)  Anyway, could
the new syscalls be used to pin a process to the cpu it was started on,
and if so, how?  Or, what would be the best way to ensure multiple qemu
instances don't all end up on the same cpu and still won't be moved
between cpus once they are running?

 Wondering...
	Juergen

PS: Yeah I tried debugging this via running qemu in qemu but got nowhere,
I'm beginning to suspect the cpus end up scribbling over each other's stack...