[libvirt PATCH v2 50/81] virsh: Add --postcopy-resume option for migrate command

[Jiri Denemark]

Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
Reviewed-by: Peter Krempa <pkrempa at redhat.com>
Reviewed-by: Pavel Hrdina <phrdina at redhat.com>
---

Notes:
    Version 2:
    - no change

 docs/manpages/virsh.rst | 9 +++++++--
 tools/virsh-domain.c    | 8 ++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst
index 965b89c99d..ecdb54fcd5 100644
--- a/docs/manpages/virsh.rst
+++ b/docs/manpages/virsh.rst
@@ -3246,7 +3246,8 @@ migrate
    migrate [--live] [--offline] [--direct] [--p2p [--tunnelled]]
       [--persistent] [--undefinesource] [--suspend] [--copy-storage-all]
       [--copy-storage-inc] [--change-protection] [--unsafe] [--verbose]
-      [--rdma-pin-all] [--abort-on-error] [--postcopy] [--postcopy-after-precopy]
+      [--rdma-pin-all] [--abort-on-error] [--postcopy]
+      [--postcopy-after-precopy] [--postcopy-resume]
       domain desturi [migrateuri] [graphicsuri] [listen-address] [dname]
       [--timeout seconds [--timeout-suspend | --timeout-postcopy]]
       [--xml file] [--migrate-disks disk-list] [--disks-port port]
@@ -3302,7 +3303,11 @@ Once migration is running, the user may switch to post-copy using the
 automatically switch to post-copy after the first pass of pre-copy is finished.
 The maximum bandwidth consumed during the post-copy phase may be limited using
 *--postcopy-bandwidth*. The maximum bandwidth consumed during the pre-copy phase
-may be limited using *--bandwidth*.
+may be limited using *--bandwidth*. In case connection between the hosts breaks
+while migration is in post-copy mode, the domain cannot be resumed on either
+source or destination host and the ``migrate`` command will report an error
+leaving the domain active on both hosts. To recover from such situation repeat
+the original ``migrate`` command with an additional *--postcopy-resume* flag.
 
 *--auto-converge* forces convergence during live migration. The initial
 guest CPU throttling rate can be set with *auto-converge-initial*. If the
diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c
index bac4cc0fb6..dd7862b5e5 100644
--- a/tools/virsh-domain.c
+++ b/tools/virsh-domain.c
@@ -10807,6 +10807,10 @@ static const vshCmdOptDef opts_migrate[] = {
      .type = VSH_OT_BOOL,
      .help = N_("automatically switch to post-copy migration after one pass of pre-copy")
     },
+    {.name = "postcopy-resume",
+     .type = VSH_OT_BOOL,
+     .help = N_("resume failed post-copy migration")
+    },
     {.name = "migrateuri",
      .type = VSH_OT_STRING,
      .completer = virshCompleteEmpty,
@@ -11210,6 +11214,9 @@ doMigrate(void *opaque)
     if (vshCommandOptBool(cmd, "postcopy"))
         flags |= VIR_MIGRATE_POSTCOPY;
 
+    if (vshCommandOptBool(cmd, "postcopy-resume"))
+        flags |= VIR_MIGRATE_POSTCOPY_RESUME;
+
     if (vshCommandOptBool(cmd, "tls"))
         flags |= VIR_MIGRATE_TLS;
 
@@ -11314,6 +11321,7 @@ cmdMigrate(vshControl *ctl, const vshCmd *cmd)
     VSH_EXCLUSIVE_OPTIONS("live", "offline");
     VSH_EXCLUSIVE_OPTIONS("timeout-suspend", "timeout-postcopy");
     VSH_REQUIRE_OPTION("postcopy-after-precopy", "postcopy");
+    VSH_REQUIRE_OPTION("postcopy-resume", "postcopy");
     VSH_REQUIRE_OPTION("timeout-postcopy", "postcopy");
     VSH_REQUIRE_OPTION("persistent-xml", "persistent");
     VSH_REQUIRE_OPTION("tls-destination", "tls");
-- 
2.35.1