Tools: Libxc wrappers to automatically fill in page oud page contents on prepare

Signed-off-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Tim Deegan <tim@xen.org>

3 files changed, 27 insertions, 2 deletions

diff --git a/tools/libxc/xc_mem_event.c b/tools/libxc/xc_mem_event.c
index b40d269709..80259071b1 100644
--- a/tools/libxc/xc_mem_event.c
+++ b/tools/libxc/xc_mem_event.c
@@ -24,7 +24,7 @@
 #include "xc_private.h"
 
 int xc_mem_event_control(xc_interface *xch, domid_t domain_id, unsigned int op,
-                         unsigned int mode, void *shared_page,
+                         unsigned int mode, void *page,
                          void *ring_page, unsigned long gfn)
 {
     DECLARE_DOMCTL;
@@ -34,7 +34,7 @@ int xc_mem_event_control(xc_interface *xch, domid_t domain_id, unsigned int op,
     domctl.u.mem_event_op.op = op;
     domctl.u.mem_event_op.mode = mode;
 
-    domctl.u.mem_event_op.shared_addr = (unsigned long)shared_page;
+    domctl.u.mem_event_op.u.shared_addr = (unsigned long)page;
     domctl.u.mem_event_op.ring_addr = (unsigned long)ring_page;
 
     domctl.u.mem_event_op.gfn = gfn;
diff --git a/tools/libxc/xc_mem_paging.c b/tools/libxc/xc_mem_paging.c
index f917403b39..f16d16b3ab 100644
--- a/tools/libxc/xc_mem_paging.c
+++ b/tools/libxc/xc_mem_paging.c
@@ -65,6 +65,29 @@ int xc_mem_paging_prep(xc_interface *xch, domid_t domain_id, unsigned long gfn)
                                 NULL, NULL, gfn);
 }
 
+int xc_mem_paging_load(xc_interface *xch, domid_t domain_id, 
+                                unsigned long gfn, void *buffer)
+{
+    int rc;
+
+    if ( !buffer )
+        return -EINVAL;
+
+    if ( ((unsigned long) buffer) & (XC_PAGE_SIZE - 1) )
+        return -EINVAL;
+
+    if ( mlock(buffer, XC_PAGE_SIZE) )
+        return -errno;
+        
+    rc = xc_mem_event_control(xch, domain_id,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING_PREP,
+                                XEN_DOMCTL_MEM_EVENT_OP_PAGING,
+                                buffer, NULL, gfn);
+
+    (void)munlock(buffer, XC_PAGE_SIZE);
+    return rc;
+}
+
 int xc_mem_paging_resume(xc_interface *xch, domid_t domain_id, unsigned long gfn)
 {
     return xc_mem_event_control(xch, domain_id,
diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h
index 5a3e48f0ee..0f45b7961b 100644
--- a/tools/libxc/xenctrl.h
+++ b/tools/libxc/xenctrl.h
@@ -1868,6 +1868,8 @@ int xc_mem_paging_nominate(xc_interface *xch, domid_t domain_id,
                            unsigned long gfn);
 int xc_mem_paging_evict(xc_interface *xch, domid_t domain_id, unsigned long gfn);
 int xc_mem_paging_prep(xc_interface *xch, domid_t domain_id, unsigned long gfn);
+int xc_mem_paging_load(xc_interface *xch, domid_t domain_id, 
+                        unsigned long gfn, void *buffer);
 int xc_mem_paging_resume(xc_interface *xch, domid_t domain_id,
                          unsigned long gfn);