hvm: handle PoD and grant pages in HVMOP_get_mem_type

During kexec in a ballooned PVonHVM guest the new kernel needs to check
each pfn if its backed by a mfn to find ballooned pages. Currently all
PoD and grant pages will appear as HVMMEM_mmio_dm, so the new kernel has
to assume they are ballooned. This is wrong: PoD pages may turn into
real RAM at runtime, grant pages are also RAM.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Tim Deegan <tim@xen.org>
xen-unstable changeset: 26093:4ae08ca5500f
xen-unstable date: Fri Oct 19 16:09:05 2012 +0200

xen/arch/x86/hvm/hvm.c

@@ -4071,6 +4071,10 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE(void) arg)
                 a.mem_type =  HVMMEM_ram_ro;
             else if ( p2m_is_ram(t) )
                 a.mem_type =  HVMMEM_ram_rw;
+            else if ( p2m_is_magic(t) )
+                a.mem_type =  HVMMEM_ram_rw;
+            else if ( p2m_is_grant(t) )
+                a.mem_type =  HVMMEM_ram_rw;
             else
                 a.mem_type =  HVMMEM_mmio_dm;
             rc = copy_to_guest(arg, &a, 1) ? -EFAULT : 0;