[Xen-devel] [PATCH v2 5/5] arm64/xen: introduce CONFIG_XEN and hypercall.S on ARM64

[Ian Campbell]

On Mon, 2013-06-03 at 17:25 +0100, Catalin Marinas wrote:
> On Mon, Jun 03, 2013 at 04:33:44PM +0100, Stefano Stabellini wrote:
> > --- /dev/null
> > +++ b/arch/arm64/xen/hypercall.S
> ...
> > +/*
> > + * The Xen hypercall calling convention is very similar to the ARM AEBI
> > + * procedure calling convention: the first paramter is passed in x0, the
> > + * second in x1, the third in x2 and the fourth in x3. Considering that
> > + * Xen hypercalls have 5 arguments at most, the fifth paramter is passed

                                                          parameter

> > + * in rx, differently from the procedure calling convention of using the

          ^x4 not rx

> > + * stack for that case.
> 
> You may want to use the AArch64 ABI here where parameters are passed in
> x0-x7, return in x0.

I think that is actually what we are doing (up to 5 arguments), the
"Considering that ..." bit at the end is a left over of the 32 bit
version I think.

> 
> BTW, I think it's missing a MAINTAINERS file update.
> 
> Otherwise, the series looks good. How do you plan to upstream this?
>