[PATCH v7 COLO 08/18] send store mfn and console mfn to xl before resuming secondary vm

[Yang Hongyang <yanghy@cn.fujitsu.com>]

From: Wen Congyang <wency@cn.fujitsu.com>

We will call libxl__xc_domain_restore_done() to rebuild secondary vm. But
we need store mfn and console mfn when rebuilding secondary vm. So make
restore_results a function pointer in callback struct and struct
{save,restore}_callbacks, and use this callback to send store mfn and
console mfn to xl.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
---
 tools/libxc/include/xenguest.h     | 8 ++++++++
 tools/libxc/xc_sr_restore.c        | 7 +++++--
 tools/libxl/libxl_colo_restore.c   | 5 -----
 tools/libxl/libxl_create.c         | 2 ++
 tools/libxl/libxl_save_msgs_gen.pl | 2 +-
 5 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/tools/libxc/include/xenguest.h b/tools/libxc/include/xenguest.h
index dcc441a..b2a9818 100644
--- a/tools/libxc/include/xenguest.h
+++ b/tools/libxc/include/xenguest.h
@@ -136,6 +136,14 @@ struct restore_callbacks {
      */
     int (*should_checkpoint)(void* data);
 
+    /*
+     * callback to send store mfn and console mfn to xl
+     * if we want to resume vm before xc_domain_save()
+     * exits.
+     */
+    void (*restore_results)(unsigned long store_mfn, unsigned long console_mfn,
+                            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 5f98927..0247e84 100644
--- a/tools/libxc/xc_sr_restore.c
+++ b/tools/libxc/xc_sr_restore.c
@@ -556,7 +556,9 @@ static int handle_checkpoint(struct xc_sr_context *ctx)
         if ( rc )
             goto err;
 
-        /* TODO: call restore_results */
+        ctx->restore.callbacks->restore_results(ctx->restore.xenstore_gfn,
+                                                ctx->restore.console_gfn,
+                                                ctx->restore.callbacks->data);
 
         /* Resume secondary vm */
         ret = ctx->restore.callbacks->postcopy(ctx->restore.callbacks->data);
@@ -839,7 +841,8 @@ int xc_domain_restore2(xc_interface *xch, int io_fd, uint32_t dom,
         /* this is COLO restore */
         assert(callbacks->suspend &&
                callbacks->postcopy &&
-               callbacks->should_checkpoint);
+               callbacks->should_checkpoint &&
+               callbacks->restore_results);
     }
 
     IPRINTF("In experimental %s", __func__);
diff --git a/tools/libxl/libxl_colo_restore.c b/tools/libxl/libxl_colo_restore.c
index 40fd170..ada9a35 100644
--- a/tools/libxl/libxl_colo_restore.c
+++ b/tools/libxl/libxl_colo_restore.c
@@ -137,11 +137,6 @@ static void colo_resume_vm(libxl__egc *egc,
         return;
     }
 
-    /*
-     * TODO: get store mfn and console mfn
-     *  We should call the callback restore_results in
-     *  xc_domain_restore() before resuming the guest.
-     */
     libxl__xc_domain_restore_done(egc, dcs, 0, 0, 0);
 
     return;
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 2380368..aaa14e3 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1148,6 +1148,8 @@ static void domcreate_bootloader_done(libxl__egc *egc,
     dcs->srs.completion_callback = domcreate_stream_done;
 
     /* colo restore setup */
+    callbacks->restore_results = libxl__srm_callout_callback_restore_results;
+
     if (checkpointed_stream == LIBXL_CHECKPOINTED_STREAM_COLO) {
         crs->ao = ao;
         crs->domid = domid;
diff --git a/tools/libxl/libxl_save_msgs_gen.pl b/tools/libxl/libxl_save_msgs_gen.pl
index 86cd395..e96673e 100755
--- a/tools/libxl/libxl_save_msgs_gen.pl
+++ b/tools/libxl/libxl_save_msgs_gen.pl
@@ -29,7 +29,7 @@ our @msgs = (
     [  6, 'srcxA',  "should_checkpoint", [] ],
     [  7, 'scxA',   "switch_qemu_logdirty",  [qw(int domid
                                               unsigned enable)] ],
-    [  8, 'r',      "restore_results",       ['unsigned long', 'store_mfn',
+    [  8, 'rcx',    "restore_results",       ['unsigned long', 'store_mfn',
                                               'unsigned long', 'console_mfn'] ],
     [  9, 'srW',    "complete",              [qw(int retval
                                                  int errnoval)] ],
-- 
1.9.1