tools/libxc: check to set args.mmio_size before call xc_hvm_build

After commit 5dff8e9eedc7, "libxc/libxl: fill xc_hvm_build_args in libxl" is introduced, we won't check to set args.mmio_size inside xc_hvm_build as before. So instead, we need to do this before call that.

---

As we discussed previously, we'd like to sent this separately. For more detail please see,

http://osdir.com/ml/general/2015-06/msg38370.html

 tools/libxc/xc_hvm_build_x86.c | 2 ++
 1 file changed, 2 insertions(+)

index 003ea06..7343e87 100644
@@ -754,6 +754,8 @@ int xc_hvm_build_target_mem(xc_interface *xch,
     args.mem_size = (uint64_t)memsize << 20;
     args.mem_target = (uint64_t)target << 20;
     args.image_file_name = image_name;
+    if ( args.mmio_size == 0 )
+        args.mmio_size = HVM_BELOW_4G_MMIO_LENGTH;
 
     return xc_hvm_build(xch, domid, &args);
 }

1.9.1

Applied, thanks.