[PATCH v1 COLO Pre 09/12] tools/libxl: Add back channel to allow migration target send data back

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

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

In colo mode, slave needs to send data to master, but the io_fd
only can be written in master, and only can be read in slave.
Save recv_fd in domain_suspend_state, and send_fd in
domain_create_state.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
---
 tools/libxl/libxl.c          |  2 +-
 tools/libxl/libxl_create.c   | 14 ++++++++++----
 tools/libxl/libxl_internal.h |  2 ++
 tools/libxl/libxl_types.idl  |  7 +++++++
 tools/libxl/xl_cmdimpl.c     |  7 +++++++
 5 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index b960984..8b15be6 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -865,7 +865,7 @@ int libxl_domain_remus_start(libxl_ctx *ctx, libxl_domain_remus_info *info,
     dss->callback = remus_failover_cb;
     dss->domid = domid;
     dss->fd = send_fd;
-    /* TODO do something with recv_fd */
+    dss->recv_fd = recv_fd;
     dss->type = type;
     dss->live = 1;
     dss->debug = 0;
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 86384d2..bd8149c 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1577,8 +1577,8 @@ static void domain_create_cb(libxl__egc *egc,
                              int rc, uint32_t domid);
 
 static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
-                            uint32_t *domid,
-                            int restore_fd, int checkpointed_stream,
+                            uint32_t *domid, int restore_fd,
+                            int send_fd, int checkpointed_stream,
                             const libxl_asyncop_how *ao_how,
                             const libxl_asyncprogress_how *aop_console_how)
 {
@@ -1591,6 +1591,7 @@ static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
     libxl_domain_config_init(&cdcs->dcs.guest_config_saved);
     libxl_domain_config_copy(ctx, &cdcs->dcs.guest_config_saved, d_config);
     cdcs->dcs.restore_fd = restore_fd;
+    cdcs->dcs.send_fd = send_fd;
     cdcs->dcs.callback = domain_create_cb;
     cdcs->dcs.checkpointed_stream = checkpointed_stream;
     libxl__ao_progress_gethow(&cdcs->dcs.aop_console_how, aop_console_how);
@@ -1619,7 +1620,7 @@ int libxl_domain_create_new(libxl_ctx *ctx, libxl_domain_config *d_config,
                             const libxl_asyncop_how *ao_how,
                             const libxl_asyncprogress_how *aop_console_how)
 {
-    return do_domain_create(ctx, d_config, domid, -1, 0,
+    return do_domain_create(ctx, d_config, domid, -1, -1, 0,
                             ao_how, aop_console_how);
 }
 
@@ -1629,7 +1630,12 @@ int libxl_domain_create_restore(libxl_ctx *ctx, libxl_domain_config *d_config,
                                 const libxl_asyncop_how *ao_how,
                                 const libxl_asyncprogress_how *aop_console_how)
 {
-    return do_domain_create(ctx, d_config, domid, restore_fd,
+    int send_fd = -1;
+
+    if (params->checkpointed_stream == LIBXL_CHECKPOINTED_STREAM_COLO)
+        send_fd = params->send_fd;
+
+    return do_domain_create(ctx, d_config, domid, restore_fd, send_fd,
                             params->checkpointed_stream, ao_how, aop_console_how);
 }
 
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 8b60fef..9cd976f 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -2873,6 +2873,7 @@ struct libxl__domain_save_state {
 
     uint32_t domid;
     int fd;
+    int recv_fd;
     libxl_domain_type type;
     int live;
     int debug;
@@ -3142,6 +3143,7 @@ struct libxl__domain_create_state {
     libxl_domain_config *guest_config;
     libxl_domain_config guest_config_saved; /* vanilla config */
     int restore_fd;
+    int send_fd;
     libxl__domain_create_cb *callback;
     libxl_asyncprogress_how aop_console_how;
     /* private to domain_create */
diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
index 23f27d4..8a3d7ba 100644
--- a/tools/libxl/libxl_types.idl
+++ b/tools/libxl/libxl_types.idl
@@ -198,6 +198,12 @@ libxl_viridian_enlightenment = Enumeration("viridian_enlightenment", [
     (3, "reference_tsc"),
     ])
 
+libxl_checkpointed_stream = Enumeration("checkpointed_stream", [
+    (0, "NONE"),
+    (1, "REMUS"),
+    (2, "COLO"),
+    ], init_val = 0)
+
 #
 # Complex libxl types
 #
@@ -346,6 +352,7 @@ libxl_domain_create_info = Struct("domain_create_info",[
 
 libxl_domain_restore_params = Struct("domain_restore_params", [
     ("checkpointed_stream", integer),
+    ("send_fd", integer),
     ])
 
 libxl_domain_sched_params = Struct("domain_sched_params",[
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index c858068..adfadd1 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -154,6 +154,7 @@ struct domain_create {
     const char *extra_config; /* extra config string */
     const char *restore_file;
     int migrate_fd; /* -1 means none */
+    int send_fd; /* -1 means none */
     char **migration_domname_r; /* from malloc */
 };
 
@@ -2533,6 +2534,7 @@ static uint32_t create_domain(struct domain_create *dom_info)
     void *config_data = 0;
     int config_len = 0;
     int restore_fd = -1;
+    int send_fd = -1;
     const libxl_asyncprogress_how *autoconnect_console_how;
     struct save_file_header hdr;
 
@@ -2549,6 +2551,7 @@ static uint32_t create_domain(struct domain_create *dom_info)
         if (migrate_fd >= 0) {
             restore_source = "<incoming migration stream>";
             restore_fd = migrate_fd;
+            send_fd = dom_info->send_fd;
         } else {
             restore_source = restore_file;
             restore_fd = open(restore_file, O_RDONLY);
@@ -2723,6 +2726,7 @@ start:
         libxl_domain_restore_params_init(&params);
 
         params.checkpointed_stream = dom_info->checkpointed_stream;
+        params.send_fd = send_fd;
         ret = libxl_domain_create_restore(ctx, &d_config,
                                           &domid, restore_fd,
                                           &params,
@@ -4266,6 +4270,7 @@ static void migrate_receive(int debug, int daemonize, int monitor,
     dom_info.monitor = monitor;
     dom_info.paused = 1;
     dom_info.migrate_fd = recv_fd;
+    dom_info.send_fd = send_fd;
     dom_info.migration_domname_r = &migration_domname;
     dom_info.checkpointed_stream = remus;
 
@@ -4436,6 +4441,7 @@ int main_restore(int argc, char **argv)
     dom_info.config_file = config_file;
     dom_info.restore_file = checkpoint_file;
     dom_info.migrate_fd = -1;
+    dom_info.send_fd = -1;
     dom_info.vnc = vnc;
     dom_info.vncautopass = vncautopass;
     dom_info.console_autoconnect = console_autoconnect;
@@ -4886,6 +4892,7 @@ int main_create(int argc, char **argv)
     dom_info.config_file = filename;
     dom_info.extra_config = extra_config;
     dom_info.migrate_fd = -1;
+    dom_info.send_fd = -1;
     dom_info.vnc = vnc;
     dom_info.vncautopass = vncautopass;
     dom_info.console_autoconnect = console_autoconnect;
-- 
1.9.1