server/spice.h: semi-seamless migration interface, RHBZ #738266

semi-seamless migration details:

migration source side
---------------------
(1) spice_server_migrate_connect (*): tell client to link
    to the target side - send SPICE_MSG_MAIN_MIGRATE_BEGIN.
    This should be called upon client_migrate_info cmd.
    client_migrate_info is asynchronous.
(2) Complete spice_server_migrate_connect only when the client has been connected
    to the target - wait for SPICE_MSGC_MAIN_MIGRATE_(CONNECTED|CONNECT_ERROR) or a timeout.
(3) spice_server_migrate_end: tell client migration it can switch to the target - send
    SPICE_MSG_MAIN_MIGRATE_END.
(4) client cleans up all data related to the connection to the source and switches to the target.
    It sends SPICE_MSGC_MAIN_MIGRATE_END.

migration target side
---------------------
(1) the server identifies itself as a migraiton target since the client is linked with (connection_id != 0)
(2) server doesn't start the channels' logic (channel->link) till it receives SPICE_MSGC_MAIN_MIGRATE_END
    from the client.

*   After migration starts, the target qemu is blocked and cannot accept new spice client
    connections. Thus, we trigger the connection to the target upon client_migrate_info
    command.
(cherry picked from commit 6e56bea67c5648b0c81990171d4bc0cf1a402043 branch 0.8)

Conflicts:

	server/spice.h

1 files changed, 26 insertions, 1 deletions

diff --git a/server/spice.h b/server/spice.h
index 74f9fdba..974975a7 100644
--- a/server/spice.h
+++ b/server/spice.h
@@ -475,8 +475,26 @@ int spice_server_set_agent_copypaste(SpiceServer *s, int enable);
 int spice_server_get_sock_info(SpiceServer *s, struct sockaddr *sa, socklen_t *salen);
 int spice_server_get_peer_info(SpiceServer *s, struct sockaddr *sa, socklen_t *salen);
 
-/* spice switch-host client migration */
+/* migration interface */
+#define SPICE_INTERFACE_MIGRATION "migration"
+#define SPICE_INTERFACE_MIGRATION_MAJOR 1
+#define SPICE_INTERFACE_MIGRATION_MINOR 1
+typedef struct SpiceMigrateInterface SpiceMigrateInterface;
+typedef struct SpiceMigrateInstance SpiceMigrateInstance;
+typedef struct SpiceMigrateState SpiceMigrateState;
+
+struct SpiceMigrateInterface {
+    SpiceBaseInterface base;
+    void (*migrate_connect_complete)(SpiceMigrateInstance *sin);
+    void (*migrate_end_complete)(SpiceMigrateInstance *sin);
+};
+
+struct SpiceMigrateInstance {
+    SpiceBaseInstance base;
+    SpiceMigrateState *st;
+};
 
+/* spice switch-host client migration */
 int spice_server_migrate_info(SpiceServer *s, const char* dest,
                               int port, int secure_port,
                               const char* cert_subject);
@@ -485,4 +503,11 @@ int spice_server_migrate_switch(SpiceServer *s);
 /* server status */
 int spice_server_get_num_clients(SpiceServer *s);
 
+/* spice (semi-)seamless client migration */
+int spice_server_migrate_connect(SpiceServer *s, const char* dest,
+                                 int port, int secure_port,
+                                 const char* cert_subject);
+int spice_server_migrate_start(SpiceServer *s);
+int spice_server_migrate_end(SpiceServer *s, int completed);
+
 #endif