userspace: Io_page.get takes pages, not bytes

Listing domains in batches of 512 should be adequate (not batches of
2M)

Signed-off-by: David Scott <dave.scott@eu.citrix.com>

userspace/domains.ml

@@ -31,11 +31,12 @@ open Lwt
 let batch_size = 512 (* number of domains to query in one hypercall *)
 
 let sizeof = stub_sizeof_domaininfo_t ()
-let getdomaininfo_buf = Cstruct.of_bigarray (Io_page.get (batch_size * sizeof))
+let getdomaininfo_buf = Cstruct.of_bigarray (Io_page.get (batch_size * sizeof / 4096))
 
 let domain_getinfolist lowest_domid =
   let number_found = stub_domain_getinfolist lowest_domid batch_size getdomaininfo_buf in
   let rec parse buf n acc =
+Printf.fprintf stderr "len(buf) = %d sizeof = %d number_found = %d n = %d %b\n%!" (Cstruct.len buf) sizeof number_found n (n = number_found);
     if n = number_found
     then acc
     else parse (Cstruct.shift buf sizeof) (n + 1) (stub_domaininfo_t_parse buf :: acc) in