libxc: introduce xc_domain_get_guest_width()

As a wrapper to XEN_DOMCTL_get_address_size, and use it
wherever the call was being issued directly via do_domctl(),
saving quite some line of code.

Actually, the function returns the guest width in bytes,
rather than directly what XEN_DOMCTL_get_address_size provides
(which is a number of bits), since that is what it is useful
almost everywhere.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index f2cebafc9d..58d51f353a 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -560,6 +560,19 @@ int xc_vcpu_getaffinity(xc_interface *xch,
                         int vcpu,
                         xc_cpumap_t cpumap);
 
+
+/**
+ * This function will return the guest_width (in bytes) for the
+ * specified domain.
+ *
+ * @param xch a handle to an open hypervisor interface.
+ * @param domid the domain id one wants the address size width of.
+ * @param addr_size the address size.
+ */
+int xc_domain_get_guest_width(xc_interface *xch, uint32_t domid,
+                              unsigned int *guest_width);
+
+
 /**
  * This function will return information about one or more domains. It is
  * designed to iterate over the list of domains. If a single domain is