[PATCH 24/27] tools/libx{c, l}: [RFC] Introduce restore_callbacks.checkpoint()

[Andrew Cooper <andrew.cooper3@citrix.com>]

And call it when a checkpoint record is found in the libxc stream.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxc/include/xenguest.h     |    3 +++
 tools/libxc/xc_sr_restore.c        |   15 ++++++++++++++-
 tools/libxl/libxl_save_msgs_gen.pl |    2 +-
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/tools/libxc/include/xenguest.h b/tools/libxc/include/xenguest.h
index 7581263..b0d27ed 100644
--- a/tools/libxc/include/xenguest.h
+++ b/tools/libxc/include/xenguest.h
@@ -102,6 +102,9 @@ struct restore_callbacks {
     int (*toolstack_restore)(uint32_t domid, const uint8_t *buf,
             uint32_t size, void* data);
 
+    /* A checkpoint record has been found in the stream */
+    int (*checkpoint)(void* data);
+
     /* to be provided as the last argument to each callback function */
     void* data;
 };
diff --git a/tools/libxc/xc_sr_restore.c b/tools/libxc/xc_sr_restore.c
index 9e27dba..5e0f817 100644
--- a/tools/libxc/xc_sr_restore.c
+++ b/tools/libxc/xc_sr_restore.c
@@ -1,5 +1,7 @@
 #include <arpa/inet.h>
 
+#include <assert.h>
+
 #include "xc_sr_common.h"
 
 /*
@@ -472,7 +474,7 @@ static int handle_page_data(struct xc_sr_context *ctx, struct xc_sr_record *rec)
 static int handle_checkpoint(struct xc_sr_context *ctx)
 {
     xc_interface *xch = ctx->xch;
-    int rc = 0;
+    int rc = 0, ret;
     unsigned i;
 
     if ( !ctx->restore.checkpointed )
@@ -482,6 +484,13 @@ static int handle_checkpoint(struct xc_sr_context *ctx)
         goto err;
     }
 
+    ret = ctx->restore.callbacks->checkpoint(ctx->restore.callbacks->data);
+    if ( ret )
+    {
+        rc = -1;
+        goto err;
+    }
+
     if ( ctx->restore.buffer_all_records )
     {
         IPRINTF("All records buffered");
@@ -735,6 +744,10 @@ int xc_domain_restore2(xc_interface *xch, int io_fd, uint32_t dom,
     ctx.restore.checkpointed = checkpointed_stream;
     ctx.restore.callbacks = callbacks;
 
+    /* Sanity checks for callbacks. */
+    if (checkpointed_stream)
+        assert(callbacks->checkpoint);
+
     IPRINTF("In experimental %s", __func__);
     DPRINTF("fd %d, dom %u, hvm %u, pae %u, superpages %d"
             ", checkpointed_stream %d", io_fd, dom, hvm, pae,
diff --git a/tools/libxl/libxl_save_msgs_gen.pl b/tools/libxl/libxl_save_msgs_gen.pl
index 6b4b65e..36b279e 100755
--- a/tools/libxl/libxl_save_msgs_gen.pl
+++ b/tools/libxl/libxl_save_msgs_gen.pl
@@ -25,7 +25,7 @@ our @msgs = (
                                                 'unsigned long', 'total'] ],
     [  3, 'scxA',   "suspend", [] ],
     [  4, 'scxA',   "postcopy", [] ],
-    [  5, 'scxA',   "checkpoint", [] ],
+    [  5, 'srcxA',   "checkpoint", [] ],
     [  6, 'scxA',   "switch_qemu_logdirty",  [qw(int domid
                                               unsigned enable)] ],
     #                toolstack_save          done entirely `by hand'
-- 
1.7.10.4