On Fri, 2012-07-27 at 16:54 +0100, Stefano Stabellini wrote:

On Fri, 27 Jul 2012, Ian Campbell wrote:

quoted

On Thu, 2012-07-26 at 16:33 +0100, Stefano Stabellini wrote:

quoted

We used to rely on a core_initcall to initialize Xen on ARM, however
core_initcalls are actually called after early consoles are initialized.
That means that hvc_xen.c is going to be initialized before Xen.

Given the lack of a better alternative, just call a new Xen
initialization function (xen_guest_init) from xen_cons_init.

Can't we just arrange for this to be called super early on from
setup_arch? That's got to be better than calling it from some random
function which happens to get called early enough.

While I agree with you that an explicit call to xen_guest_init from
generic code might be better, xen_cons_init is not just a random
function: it is a console_initcall and therefore we know for sure that
it is going be the first one to be called.

Initialising something != console in a console_initcall just because it
happens to be called early enough meets my definition of calling it from
a random place.

In fact if we didn't want the PV console to work so early we could just
rely on a core_initcall to initialize everything and we wouldn't have
any issues.


In any case if the ARM maintainers agree I could add a generic
hypervisor initialization call the end of setup_arch.

quoted

I presume that KVM is going to want some similarly early init hooks etc
and therefore ARM could benefit from the same sort of infrastructure as
is in arch/x86/include/asm/hypervisor.h?