Re: [Xen-devel] [PATCH v12 for-xen-4.5 01/20] common/symbols: Export hypervisor symbols to privileged guest

[Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>]

> diff --git a/xen/include/public/platform.h b/xen/include/public/platform.h
> index 053b9fa..4f21b17 100644
> --- a/xen/include/public/platform.h
> +++ b/xen/include/public/platform.h
> @@ -527,6 +527,24 @@ struct xenpf_core_parking {
>  typedef struct xenpf_core_parking xenpf_core_parking_t;
>  DEFINE_XEN_GUEST_HANDLE(xenpf_core_parking_t);
>  
> +#define XENPF_get_symbol   61
> +struct xenpf_symdata {
> +    /* IN/OUT variables */
> +    uint32_t namelen; /* IN:  size of name buffer                       */
> +                      /* OUT: strlen(name) of hypervisor symbol (may be */
> +                      /*      larger than what's been copied to guest)  */
> +    uint32_t symnum;  /* IN:  Symbol to read                            */
> +                      /* OUT: Next available symbol. If same as IN then */
> +                      /*      we reached the end                        */
> +
> +    /* OUT variables */
> +    char type;
> +    XEN_GUEST_HANDLE(char) name;
> +    uint64_t address;
> +};
> +typedef struct xenpf_symdata xenpf_symdata_t;

This is what 'pahole' says:

struct xenpf_symdata {                                                          
    uint32_t                   namelen;              /*     0     4 */          
    uint32_t                   symnum;               /*     4     4 */          
    char                       type;                 /*     8     1 */          
                                                                                
    /* XXX 7 bytes hole, try to pack */                                         
                                                                                
    __guest_handle_char        name;                 /*    16     8 */          
    uint64_t                   address;              /*    24     8 */          
                                                                                
    /* size: 32, cachelines: 1, members: 5 */                                   
    /* sum members: 25, holes: 1, sum holes: 7 */                               
    /* last cacheline: 32 bytes */                                              
};                                            

If I move them just a bit:


diff --git a/xen/include/public/platform.h b/xen/include/public/platform.h
index 4f21b17..b97e476 100644
--- a/xen/include/public/platform.h
+++ b/xen/include/public/platform.h
@@ -538,9 +538,9 @@ struct xenpf_symdata {
                       /*      we reached the end                        */
 
     /* OUT variables */
-    char type;
-    XEN_GUEST_HANDLE(char) name;
     uint64_t address;
+    XEN_GUEST_HANDLE(char) name;
+    char type;
 };
 typedef struct xenpf_symdata xenpf_symdata_t;
 DEFINE_XEN_GUEST_HANDLE(xenpf_symdata_t);


'pahole' is satisfied:

struct xenpf_symdata {                                                          
    uint32_t                   namelen;              /*     0     4 */          
    uint32_t                   symnum;               /*     4     4 */          
    uint64_t                   address;              /*     8     8 */          
    __guest_handle_char        name;                 /*    16     8 */          
    char                       type;                 /*    24     1 */          
                                                                                
    /* size: 32, cachelines: 1, members: 5 */                                   
    /* padding: 7 */                                                            
    /* last cacheline: 32 bytes */                                              
};                                    


With that change, Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel