tools: cleanup domain save switch_qemu_logdirty callback

Move the function into struct save_callbacks with the others and add
the void *closure to the callback arguments.

Add and propagate an error return code from the callback.

Use this in libxl to pass the save context to
libxl__domain_suspend_common_switch_qemu_logdirty allowing us to reuse
the parent's xenstore handle, gc context etc.

Also add an apparently missing libxl__free_all to
libxl__domain_suspend_common.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c
index b6e239200b..47f8a79c9d 100644
--- a/tools/libxc/xc_domain_save.c
+++ b/tools/libxc/xc_domain_save.c
@@ -873,8 +873,7 @@ static int save_tsc_info(xc_interface *xch, uint32_t dom, int io_fd)
 
 int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iters,
                    uint32_t max_factor, uint32_t flags,
-                   struct save_callbacks* callbacks,
-                   int hvm, void (*switch_qemu_logdirty)(int, unsigned))
+                   struct save_callbacks* callbacks, int hvm)
 {
     xc_dominfo_t info;
     DECLARE_DOMCTL;
@@ -938,6 +937,13 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
 
     int completed = 0;
 
+    if ( hvm && !callbacks->switch_qemu_logdirty )
+    {
+        ERROR("No switch_qemu_logdirty callback provided.");
+        errno = EINVAL;
+        return 1;
+    }
+
     outbuf_init(xch, &ob, OUTBUF_SIZE);
 
     /* If no explicit control parameters given, use defaults */
@@ -1009,8 +1015,11 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
         }
 
         /* Enable qemu-dm logging dirty pages to xen */
-        if ( hvm )
-            switch_qemu_logdirty(dom, 1);
+        if ( hvm && !callbacks->switch_qemu_logdirty(dom, 1, callbacks->data) )
+        {
+            PERROR("Couldn't enable qemu log-dirty mode (errno %d)", errno);
+            goto out;
+        }
     }
     else
     {
@@ -1870,8 +1879,8 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter
                                XEN_DOMCTL_SHADOW_OP_OFF,
                                NULL, 0, NULL, 0, NULL) < 0 )
             DPRINTF("Warning - couldn't disable shadow mode");
-        if ( hvm )
-            switch_qemu_logdirty(dom, 0);
+        if ( hvm && !callbacks->switch_qemu_logdirty(dom, 0, callbacks->data) )
+            DPRINTF("Warning - couldn't disable qemu log-dirty mode");
     }
 
     if ( live_shinfo )