libxc: New hcall_buf_{prep,release} pre-mlock interface

Allow certain performance-critical hypercall wrappers to register data
buffers via a new interface which allows them to be 'bounced' into a
pre-mlock'ed page-sized per-thread data area. This saves the cost of
mlock/munlock on every such hypercall, which can be very expensive on
modern kernels.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/tools/libxc/xc_physdev.c b/tools/libxc/xc_physdev.c
index ec0ebbeb76..00ac829afa 100644
--- a/tools/libxc/xc_physdev.c
+++ b/tools/libxc/xc_physdev.c
@@ -36,7 +36,7 @@ int xc_physdev_map_pirq(int xc_handle,
     map.index = index;
     map.pirq = *pirq;
 
-    rc = do_physdev_op(xc_handle, PHYSDEVOP_map_pirq, &map);
+    rc = do_physdev_op(xc_handle, PHYSDEVOP_map_pirq, &map, sizeof(map));
 
     if ( !rc )
         *pirq = map.pirq;
@@ -68,7 +68,7 @@ int xc_physdev_map_pirq_msi(int xc_handle,
     map.entry_nr = entry_nr;
     map.table_base = table_base;
 
-    rc = do_physdev_op(xc_handle, PHYSDEVOP_map_pirq, &map);
+    rc = do_physdev_op(xc_handle, PHYSDEVOP_map_pirq, &map, sizeof(map));
 
     if ( !rc )
         *pirq = map.pirq;
@@ -86,7 +86,7 @@ int xc_physdev_unmap_pirq(int xc_handle,
     unmap.domid = domid;
     unmap.pirq = pirq;
 
-    rc = do_physdev_op(xc_handle, PHYSDEVOP_unmap_pirq, &unmap);
+    rc = do_physdev_op(xc_handle, PHYSDEVOP_unmap_pirq, &unmap, sizeof(unmap));
 
     return rc;
 }