Re: [Xen-devel] [PATCH 10/10] arm: parameter guest handles are 32 bit on 32 bit hypervisor

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Wed, 2012-10-17 at 14:50 +0100, Stefano Stabellini wrote:
> On Mon, 15 Oct 2012, Ian Campbell wrote:
> > Handles within structs remain 64 bit such that they are consistently
> > sized on both 32 and 64 bit.
> > 
> > Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> > ---
> >  xen/include/public/arch-arm.h |    2 +-
> >  1 files changed, 1 insertions(+), 1 deletions(-)
> > 
> > diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
> > index ac493a5..ff02d15 100644
> > --- a/xen/include/public/arch-arm.h
> > +++ b/xen/include/public/arch-arm.h
> > @@ -74,7 +74,7 @@
> >  #define __XEN_GUEST_HANDLE(name)        __guest_handle_64_ ## name
> >  #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
> >  /* this is going to be changed on 64 bit */
> > -#define XEN_GUEST_HANDLE_PARAM(name)   XEN_GUEST_HANDLE(name)
> > +#define XEN_GUEST_HANDLE_PARAM(name)    __guest_handle_ ## name
> >  #define set_xen_guest_handle_raw(hnd, val)                  \
> >      do {                                                    \
> >          typeof(&(hnd)) _sxghr_tmp = &(hnd);                 \
> 
> I am confused.
> 
> I am not sure what version of my patch "xen: introduce
> XEN_GUEST_HANDLE_PARAM" you have based this series upon, because the
> latest one I have sent, certainly contains this change:

That stuff is in "xen: introduce XEN_GUEST_HANDLE_PARAM". I had to defer
the final switch until after the transition to HANDLE_PARAM was complete
in order to avoid breaking the build in the interim.

> 
> 
> diff --git a/xen/include/public/arch-arm.h b/xen/include/public/arch-arm.h
> index 2ae6548..4c6d607 100644
> --- a/xen/include/public/arch-arm.h
> +++ b/xen/include/public/arch-arm.h
> @@ -51,18 +51,36 @@
>  
>  #define XEN_HYPERCALL_TAG   0XEA1
>  
> +#define uint64_aligned_t uint64_t __attribute__((aligned(8)))
>  
>  #ifndef __ASSEMBLY__
> -#define ___DEFINE_XEN_GUEST_HANDLE(name, type) \
> -    typedef struct { type *p; } __guest_handle_ ## name
> +#define ___DEFINE_XEN_GUEST_HANDLE(name, type)                  \
> +    typedef union { type *p; unsigned long q; }                 \
> +        __guest_handle_ ## name;                                \
> +    typedef union { type *p; uint64_aligned_t q; }              \
> +        __guest_handle_64_ ## name;
>  
> +/*
> + * XEN_GUEST_HANDLE represents a guest pointer, when passed as a field
> + * in a struct in memory. On ARM is always 8 bytes sizes and 8 bytes
> + * aligned.
> + * XEN_GUEST_HANDLE_PARAM represent a guest pointer, when passed as an
> + * hypercall argument. It is 4 bytes on aarch and 8 bytes on aarch64.
> + */
>  #define __DEFINE_XEN_GUEST_HANDLE(name, type) \
>      ___DEFINE_XEN_GUEST_HANDLE(name, type);   \
>      ___DEFINE_XEN_GUEST_HANDLE(const_##name, const type)
>  #define DEFINE_XEN_GUEST_HANDLE(name)   __DEFINE_XEN_GUEST_HANDLE(name, name)
> -#define __XEN_GUEST_HANDLE(name)        __guest_handle_ ## name
> +#define __XEN_GUEST_HANDLE(name)        __guest_handle_64_ ## name
>  #define XEN_GUEST_HANDLE(name)          __XEN_GUEST_HANDLE(name)
> -#define set_xen_guest_handle_raw(hnd, val)  do { (hnd).p = val; } while (0)
> +/* this is going to be changes on 64 bit */
> +#define XEN_GUEST_HANDLE_PARAM(name)    __guest_handle_ ## name
> 



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