[PATCH v9 17/25] implement the cmdline for COLO

[Wen Congyang <wency@cn.fujitsu.com>]

Add a new option -c to the command 'xl remus'. If you want
to use COLO HA instead of Remus HA, please use -c option.

Update man pages to reflect the addition of a new option to
'xl remus' command.

Also add a new option -c to the internal command 'xl migrate-receive'.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yang Hongyang <hongyang.yang@easystack.cn>
---
 docs/man/xl.pod.1         | 12 +++++++--
 tools/libxl/libxl.c       | 23 ++++++++++++++++--
 tools/libxl/xl_cmdimpl.c  | 62 ++++++++++++++++++++++++++++++++++++-----------
 tools/libxl/xl_cmdtable.c |  4 ++-
 4 files changed, 82 insertions(+), 19 deletions(-)

diff --git a/docs/man/xl.pod.1 b/docs/man/xl.pod.1
index 4279c7c..1c6dd87 100644
--- a/docs/man/xl.pod.1
+++ b/docs/man/xl.pod.1
@@ -447,12 +447,15 @@ Print huge (!) amount of debug during the migration process.
 
 =item B<remus> [I<OPTIONS>] I<domain-id> I<host>
 
-Enable Remus HA for domain. By default B<xl> relies on ssh as a transport
-mechanism between the two hosts.
+Enable Remus HA or COLO HA for domain. By default B<xl> relies on ssh as a
+transport mechanism between the two hosts.
 
 N.B: Remus support in xl is still in experimental (proof-of-concept) phase.
      Disk replication support is limited to DRBD disks.
 
+     COLO support in xl is still in experimental (proof-of-concept) phase.
+     There is no support for network or disk at the moment.
+
 B<OPTIONS>
 
 =over 4
@@ -498,6 +501,11 @@ Disable network output buffering. Requires enabling unsafe mode.
 
 Disable disk replication. Requires enabling unsafe mode.
 
+=item B<-c>
+
+Enable COLO HA. This conflicts with B<-i> and B<-b>, and memory
+checkpoint compression must be disabled.
+
 =back
 
 =item B<pause> I<domain-id>
diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 7d227d7..ca6bca1 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -851,12 +851,28 @@ int libxl_domain_remus_start(libxl_ctx *ctx, libxl_domain_remus_info *info,
         goto out;
     }
 
+    /* The caller must set this defbool */
+    if (libxl_defbool_is_default(info->colo)) {
+        LOG(ERROR, "colo mode must be enabled/disabled");
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
     libxl_defbool_setdefault(&info->allow_unsafe, false);
     libxl_defbool_setdefault(&info->blackhole, false);
-    libxl_defbool_setdefault(&info->compression, true);
+    libxl_defbool_setdefault(&info->compression,
+                             !libxl_defbool_val(info->colo));
     libxl_defbool_setdefault(&info->netbuf, true);
     libxl_defbool_setdefault(&info->diskbuf, true);
 
+    if (libxl_defbool_val(info->colo)) {
+        if (libxl_defbool_val(info->compression)) {
+            LOG(ERROR, "cannot use memory checkpoint compression in COLO mode");
+            rc = ERROR_FAIL;
+            goto out;
+        }
+    }
+
     if (!libxl_defbool_val(info->allow_unsafe) &&
         (libxl_defbool_val(info->blackhole) ||
          !libxl_defbool_val(info->netbuf) ||
@@ -878,7 +894,10 @@ int libxl_domain_remus_start(libxl_ctx *ctx, libxl_domain_remus_info *info,
     dss->live = 1;
     dss->debug = 0;
     dss->remus = info;
-    dss->checkpointed_stream = LIBXL_CHECKPOINTED_STREAM_REMUS;
+    if (libxl_defbool_val(info->colo))
+        dss->checkpointed_stream = LIBXL_CHECKPOINTED_STREAM_COLO;
+    else
+        dss->checkpointed_stream = LIBXL_CHECKPOINTED_STREAM_REMUS;
 
     assert(info);
 
diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 6580b59..70b8b82 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -4435,6 +4435,8 @@ static void migrate_receive(int debug, int daemonize, int monitor,
     char rc_buf;
     char *migration_domname;
     struct domain_create dom_info;
+    const char *ha = checkpointed == LIBXL_CHECKPOINTED_STREAM_COLO ?
+                     "COLO" : "Remus";
 
     signal(SIGPIPE, SIG_IGN);
     /* if we get SIGPIPE we'd rather just have it as an error */
@@ -4455,6 +4457,9 @@ static void migrate_receive(int debug, int daemonize, int monitor,
     dom_info.send_fd = send_fd;
     dom_info.migration_domname_r = &migration_domname;
     dom_info.checkpointed_stream = checkpointed;
+    if (checkpointed == LIBXL_CHECKPOINTED_STREAM_COLO)
+        /* COLO uses stdout to send control message to master */
+        dom_info.quiet = 1;
 
     rc = create_domain(&dom_info);
     if (rc < 0) {
@@ -4467,11 +4472,12 @@ static void migrate_receive(int debug, int daemonize, int monitor,
 
     switch (checkpointed) {
     case LIBXL_CHECKPOINTED_STREAM_REMUS:
+    case LIBXL_CHECKPOINTED_STREAM_COLO:
         /* If we are here, it means that the sender (primary) has crashed.
          * TODO: Split-Brain Check.
          */
-        fprintf(stderr, "migration target: Remus Failover for domain %u\n",
-                domid);
+        fprintf(stderr, "migration target: %s Failover for domain %u\n",
+                ha, domid);
 
         /*
          * If domain renaming fails, lets just continue (as we need the domain
@@ -4487,16 +4493,20 @@ static void migrate_receive(int debug, int daemonize, int monitor,
             rc = libxl_domain_rename(ctx, domid, migration_domname,
                                      common_domname);
             if (rc)
-                fprintf(stderr, "migration target (Remus): "
+                fprintf(stderr, "migration target (%s): "
                         "Failed to rename domain from %s to %s:%d\n",
-                        migration_domname, common_domname, rc);
+                        ha, migration_domname, common_domname, rc);
         }
 
+        if (checkpointed == LIBXL_CHECKPOINTED_STREAM_COLO)
+            /* The guest is running after failover in COLO mode */
+            exit(rc ? -ERROR_FAIL: 0);
+
         rc = libxl_domain_unpause(ctx, domid);
         if (rc)
-            fprintf(stderr, "migration target (Remus): "
+            fprintf(stderr, "migration target (%s): "
                     "Failed to unpause domain %s (id: %u):%d\n",
-                    common_domname, domid, rc);
+                    ha, common_domname, domid, rc);
 
         exit(rc ? -ERROR_FAIL: 0);
     default:
@@ -4644,7 +4654,7 @@ int main_migrate_receive(int argc, char **argv)
     libxl_checkpointed_stream checkpointed = LIBXL_CHECKPOINTED_STREAM_NONE;
     int opt;
 
-    SWITCH_FOREACH_OPT(opt, "Fedr", NULL, "migrate-receive", 0) {
+    SWITCH_FOREACH_OPT(opt, "Fedrc", NULL, "migrate-receive", 0) {
     case 'F':
         daemonize = 0;
         break;
@@ -4658,6 +4668,9 @@ int main_migrate_receive(int argc, char **argv)
     case 'r':
         checkpointed = LIBXL_CHECKPOINTED_STREAM_REMUS;
         break;
+    case 'c':
+        checkpointed = LIBXL_CHECKPOINTED_STREAM_COLO;
+        break;
     }
 
     if (argc-optind != 0) {
@@ -8023,11 +8036,8 @@ int main_remus(int argc, char **argv)
     int config_len;
 
     memset(&r_info, 0, sizeof(libxl_domain_remus_info));
-    /* Defaults */
-    r_info.interval = 200;
-    libxl_defbool_setdefault(&r_info.blackhole, false);
 
-    SWITCH_FOREACH_OPT(opt, "Fbundi:s:N:e", NULL, "remus", 2) {
+    SWITCH_FOREACH_OPT(opt, "Fbundi:s:N:ec", NULL, "remus", 2) {
     case 'i':
         r_info.interval = atoi(optarg);
         break;
@@ -8055,11 +8065,32 @@ int main_remus(int argc, char **argv)
     case 'e':
         daemonize = 0;
         break;
+    case 'c':
+        libxl_defbool_set(&r_info.colo, true);
     }
 
     domid = find_domain(argv[optind]);
     host = argv[optind + 1];
 
+    /* Defaults */
+    libxl_defbool_setdefault(&r_info.blackhole, false);
+    libxl_defbool_setdefault(&r_info.colo, false);
+    if (!libxl_defbool_val(r_info.colo) && !r_info.interval)
+        r_info.interval = 200;
+
+    if (libxl_defbool_val(r_info.colo)) {
+        if (r_info.interval || libxl_defbool_val(r_info.blackhole)) {
+            perror("Option -c conflicts with -i or -b");
+            exit(-1);
+        }
+
+        if (libxl_defbool_is_default(r_info.compression)) {
+            perror("COLO can't be used with memory compression. "
+                   "Disable memory checkpoint compression now...");
+            libxl_defbool_set(&r_info.compression, false);
+        }
+    }
+
     if (!r_info.netbufscript)
         r_info.netbufscript = default_remus_netbufscript;
 
@@ -8074,8 +8105,9 @@ int main_remus(int argc, char **argv)
         if (!ssh_command[0]) {
             rune = host;
         } else {
-            xasprintf(&rune, "exec %s %s xl migrate-receive -r %s",
+            xasprintf(&rune, "exec %s %s xl migrate-receive %s %s",
                       ssh_command, host,
+                      libxl_defbool_val(r_info.colo) ? "-c" : "-r",
                       daemonize ? "" : " -e");
         }
 
@@ -8103,7 +8135,8 @@ int main_remus(int argc, char **argv)
      * domain to force failover
      */
     if (libxl_domain_info(ctx, 0, domid)) {
-        fprintf(stderr, "Remus: Primary domain has been destroyed.\n");
+        fprintf(stderr, "%s: Primary domain has been destroyed.\n",
+                libxl_defbool_val(r_info.colo) ? "COLO" : "Remus");
         close(send_fd);
         return 0;
     }
@@ -8115,7 +8148,8 @@ int main_remus(int argc, char **argv)
     if (rc == ERROR_GUEST_TIMEDOUT)
         fprintf(stderr, "Failed to suspend domain at primary.\n");
     else {
-        fprintf(stderr, "Remus: Backup failed? resuming domain at primary.\n");
+        fprintf(stderr, "%s: Backup failed? resuming domain at primary.\n",
+                libxl_defbool_val(r_info.colo) ? "COLO" : "Remus");
         libxl_domain_resume(ctx, domid, 1, 0);
     }
 
diff --git a/tools/libxl/xl_cmdtable.c b/tools/libxl/xl_cmdtable.c
index fdc1ac6..b6b630c 100644
--- a/tools/libxl/xl_cmdtable.c
+++ b/tools/libxl/xl_cmdtable.c
@@ -499,7 +499,9 @@ struct cmd_spec cmd_table[] = {
       "-b                      Replicate memory checkpoints to /dev/null (blackhole).\n"
       "                        Works only in unsafe mode.\n"
       "-n                      Disable network output buffering. Works only in unsafe mode.\n"
-      "-d                      Disable disk replication. Works only in unsafe mode."
+      "-d                      Disable disk replication. Works only in unsafe mode.\n"
+      "-c                      Enable COLO HA. It is conflict with -i and -b, and memory\n"
+      "                        checkpoint must be disabled"
     },
 #endif
     { "devd",
-- 
2.5.0