Re: [RFC PATCH 1/15]: PVH xen: turn gdb_frames/gdt_ents into union

[Mukesh Rathor <mukesh.rathor@oracle.com>]

On Mon, 14 Jan 2013 11:18:55 +0000
"Jan Beulich" <JBeulich@suse.com> wrote:

> >>> On 12.01.13 at 02:25, Mukesh Rathor <mukesh.rathor@oracle.com>
> >>> wrote:
> > --- a/xen/include/public/arch-x86/xen.h	Tue Oct 30 18:12:11
> > 2012 +0000 +++ b/xen/include/public/arch-x86/xen.h	Fri Jan
> > 11 16:19:40 2013 -0800 @@ -157,7 +157,16 @@ struct
> > vcpu_guest_context { struct cpu_user_regs user_regs;         /*
> > User-level CPU registers     */ struct trap_info
> > trap_ctxt[256];        /* Virtual IDT                  */ unsigned
> > long ldt_base, ldt_ents;       /* LDT (linear address, # ents) */
> > -    unsigned long gdt_frames[16], gdt_ents; /* GDT (machine
> > frames, # ents) */
> > +    union {
> > +        struct {
> > +            /* GDT (machine frames, # ents) */
> > +            unsigned long gdt_frames[16], gdt_ents;
> > +        } pv;
> > +        struct {
> > +            /* PVH: GDTR addr and size */   
> > +            unsigned long gdtaddr, gdtsz;
> > +        } pvh;
> > +    } u;
> 
> This, being a public header, needs a __XEN_INTERFACE_VERSION__
> guard so that consumers updating the header (without updating
> their interface version) would still build.

Done. Thanks.

+#if __XEN_INTERFACE_VERSION__ < 0x00040300
+    unsigned long gdt_frames[16], gdt_ents; /* GDT (machine frames, # ents) */
+#else
     union {
         struct {
             /* GDT (machine frames, # ents) */
@@ -167,6 +170,7 @@ struct vcpu_guest_context {
             unsigned long gdtaddr, gdtsz;
         } pvh;
     } u;
+#endif