[RFC PATCH 2/2] ARM: SMP support for mach-virt

[Stefano Stabellini]

On Tue, 11 Dec 2012, Will Deacon wrote:
> > > > On the Xen side there are not going to be any problems related to SMP
> > > > and holding pens, because secondary CPUs only come into existence after
> > > > the first CPU calls the HYPERVISOR_vcpu_op hypercall (still missing on
> > > > ARM).
> > > 
> > > Ok. Would you be willing/able to wrap this in a PSCI interface when you do
> > > add SMP support for ARM?
> > 
> > I grepped for PSCI in the Linux tree but I couldn't find anything.
> > Also I googled for ARM PSCI and nothing of value came up. Can I find a
> > doc that explains what PSCI is anywhere?
> 
> There is an initial version of the document here (requires registration):
> 
>   https://silver.arm.com/download/download.tm?pv=1303201
> 
> Note that there are some updates due to clarify things a bit in areas such
> as function ID numbers and the PCS. Marc and I also plan to hack something up
> in kvm/mach-virt for booting secondary CPUs.

Ideally the functionalities would be discoverable via DT, so that PSCI,
PSCI-HVC and a paravirtualized Xen interface based on hypercalls and
xenbus could all coexist without issues, reusing the same internal Linux
APIs.