[PATCH v1 07/10] libxl: make libxl_cd_insert "eject" + "insert"

[Wei Liu <wei.liu2@citrix.com>]

A "cdrom insert" is always processed as "eject" + "insert", with JSON
config updated in between. So that we can know the correct state of
CDROM later when we try to retrieve domain configuration: if xenstore is
"empty", then CDROM is "empty"; otherwise use the information presented
in JSON.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 tools/libxl/libxl.c          |   48 ++++++++++++++++++++++++++++++++++++++++--
 tools/libxl/libxl_internal.h |   34 ++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 58f07d2..69d94b1 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -2654,8 +2654,9 @@ int libxl_device_disk_getinfo(libxl_ctx *ctx, uint32_t domid,
     return 0;
 }
 
-int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid, libxl_device_disk *disk,
-                       const libxl_asyncop_how *ao_how)
+static int libxl__cdrom_insert(libxl_ctx *ctx, uint32_t domid,
+                               libxl_device_disk *disk,
+                               const libxl_asyncop_how *ao_how)
 {
     AO_CREATE(ctx, domid, ao_how);
     int num = 0, i;
@@ -2766,6 +2767,49 @@ out:
     return AO_INPROGRESS;
 }
 
+/*
+ * A "cdrom insert" is always processed as "eject" + "insert", with
+ * updating JSON in between. So that we can know the current state of
+ * CDROM later when we try to retrieve domain configuration: if
+ * xenstore is "empty", then CDROM is "empty"; otherwise use the image
+ * in JSON.
+ */
+int libxl_cdrom_insert(libxl_ctx *ctx, uint32_t domid, libxl_device_disk *disk,
+                       const libxl_asyncop_how *ao_how)
+{
+    GC_INIT(ctx);
+    libxl_device_disk empty;
+    int rc;
+    int lock = -1;
+
+    libxl_device_disk_init(&empty);
+    empty.format = LIBXL_DISK_FORMAT_EMPTY;
+    empty.vdev = libxl__strdup(NOGC, disk->vdev);
+    empty.is_cdrom = 1;
+
+    rc = libxl__cdrom_insert(ctx, domid, &empty, NULL);
+    if (rc)
+        goto out;
+
+    LOCK_DOMAIN_JSON_CONFIG(gc, domid, lock, rc);
+    if (rc)
+        goto out;
+    DEVICE_UPDATE_JSON(disk, disks, num_disks, domid, disk,
+                       COMPARE_DISK, rc);
+    UNLOCK_DOMAIN_JSON_CONFIG(gc, domid, lock);
+    if (rc)
+        goto out;
+
+    rc = libxl__cdrom_insert(ctx, domid, disk, ao_how);
+    if (rc)
+        goto out;
+
+out:
+    libxl_device_disk_dispose(&empty);
+    GC_FREE;
+    return rc;
+}
+
 /* libxl__alloc_vdev only works on the local domain, that is the domain
  * where the toolstack is running */
 static char * libxl__alloc_vdev(libxl__gc *gc, void *get_vdev_user,
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index b4f518a..f8f2ba2 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3355,6 +3355,40 @@ static inline void libxl__update_config_vtpm(libxl__gc *gc,
         libxl_domain_config_dispose(&d_config);                         \
     } while (0)
 
+/* Search device list for device with the same identifier as "dev",
+ * update that device with the content pointed to by "dev".
+ */
+#define DEVICE_UPDATE_JSON(type, ptr, cnt, domid, dev, compare, rc)     \
+    do {                                                                \
+        int x;                                                          \
+        libxl_domain_config d_config;                                   \
+        bool updated = false;                                           \
+                                                                        \
+        if (domid == LIBXL_TOOLSTACK_DOMID)                             \
+            break;                                                      \
+                                                                        \
+        libxl_domain_config_init(&d_config);                            \
+                                                                        \
+        rc = libxl__get_domain_configuration(gc, domid, &d_config);     \
+        if (rc)                                                         \
+            goto update_done;                                           \
+                                                                        \
+        for (x = 0; x < d_config.cnt; x++) {                            \
+            if (compare(&d_config.ptr[x], (dev))) {                     \
+                libxl_device_##type##_dispose(&d_config.ptr[x]);        \
+                libxl_device_##type##_copy(CTX, &d_config.ptr[x],       \
+                                           (dev));                      \
+                updated = true;                                         \
+            }                                                           \
+        }                                                               \
+                                                                        \
+        if (updated)                                                    \
+            rc = libxl__set_domain_configuration(gc, domid, &d_config); \
+                                                                        \
+    update_done:                                                        \
+        libxl_domain_config_dispose(&d_config);                         \
+    } while (0)
+
 #endif
 
 /*
-- 
1.7.10.4