Confusion about copy_to/from_guest

[Tej <bewith.tej@gmail.com>]

All,

Small and naive question about the semantics of copy_to/from_guest. In
Kernel space I have created a linked list lets say 10 elements. Now I
have created similar list in hypervisor.

Now passing the list_head from kernel using hypercall. Now how do I
copy the element between kernel and hypervisor.

1. copy_from_guest(hyp_list_head, arg, 1) or
copy_from_guest(hyp_list_head, arg, <num_of_elements_list>)
2. copy_to_guest(arg, hyp_list_head, 1) or copy_to_guest(arg,
hyp_list_head, <num of element in list>)

2nd question:
I did first one, but first element of list was not accessible in
hypervisor space, why?


It looks like I am doing something horribly wrong, so can someone
point out that.

Thanks for any help
-tej