[Spice-devel] [RFC PATCH spice 0.8 01/19] server/spice.h: semi-seamless migration interface, RHBZ #738266

[Yonit Halperin]

semi-seamless migration details:

migration source side
---------------------
(1) spice_server_migrate_info (*): tell client to link
    to the target side - send SPICE_MSG_MAIN_MIGRATE_BEGIN.
    client_migrate_info cmd is asynchronous.
(2) Complete client_migrate_info 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.

Signed-off-by: Yonit Halperin <yhalperi at redhat.com>
---
 server/spice-experimental.h |    3 ---
 server/spice.h              |   21 ++++++++++++++++++++-
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/server/spice-experimental.h b/server/spice-experimental.h
index 482ac44..6997aa0 100644
--- a/server/spice-experimental.h
+++ b/server/spice-experimental.h
@@ -29,16 +29,13 @@ void spice_server_net_wire_recv_packet(SpiceNetWireInstance *sin,
                                        const uint8_t *pkt, int len);
 
 /* spice seamless client migration (broken) */
-
 enum {
     SPICE_MIGRATE_CLIENT_NONE = 1,
     SPICE_MIGRATE_CLIENT_WAITING,
     SPICE_MIGRATE_CLIENT_READY,
 };
 
-int spice_server_migrate_start(SpiceServer *s);
 int spice_server_migrate_client_state(SpiceServer *s);
-int spice_server_migrate_end(SpiceServer *s, int completed);
 
 #endif // __SPICE_EXPERIMENTAL_H__
 
diff --git a/server/spice.h b/server/spice.h
index ac5a41e..8f7bcac 100644
--- a/server/spice.h
+++ b/server/spice.h
@@ -469,11 +469,30 @@ 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_info_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);
 int spice_server_migrate_switch(SpiceServer *s);
 
+int spice_server_migrate_start(SpiceServer *s);
+int spice_server_migrate_end(SpiceServer *s, int completed);
 #endif
-- 
1.7.4.4