Re: [PATCH 2/4] xen/public: arm: Rework __guest_handle_param*

[Ian Campbell <ian.campbell@citrix.com>]

On Mon, 2015-11-02 at 15:24 +0000, Julien Grall wrote:
> Hi Stefano,
> 
> On 02/11/15 15:19, Stefano Stabellini wrote:
> > On Fri, 30 Oct 2015, Julien Grall wrote:
> > > __guest_handle_param is used to represent a guest pointer stored pass
> > > as
> > > an hypercall parameters. They are the same size as the native
> > > register
> > > for the architecture. It will be 32-bit on ARM32 and 64-bit on ARM64.
> > > 
> > > As the __guest_handle_param will always be the size of a native
> > > pointer, there is no need to have a union with an unsigned long.
> > > 
> > > Note that unsigned long may be not equivalent to the size of a
> > > pointer
> > > on ARM64. It depends whether the software is build using the LP64 or
> > > LLP64 data model. The size of an unsigned long in the latter will be
> > > 32-bit.
> > > 
> > > Signed-off-by: Julien Grall <julien.grall@citrix.com>
> > 
> > Obviously this is going to break set_xen_guest_handle_raw. I don't
> > think
> > this cannot be committed separately to the change to
> > set_xen_guest_handle_raw.
> 
> Well, all the usage of set_xen_guest_handle_raw within the hypervisor
> are in compat and kexec which is not built for ARM.

Shall we drop it from ARM then?

It can always be added back when it is needed (or the code in question
reworked to avoid the need).

> 
> Furthermore, after this series set_xen_guest_handle_raw won't work
> anymore with a guest_handle_param.
> 
> Regards,
>