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

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

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:


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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