Re: [PATCH V3 5/9] migration: cpr-exec-command parameter

[Steven Sistare]

On 9/8/2025 12:07 PM, Daniel P. Berrangé wrote:

On Thu, Aug 14, 2025 at 10:17:19AM -0700, Steve Sistare wrote:

Create the cpr-exec-command migration parameter, defined as a list of
strings.  It will be used for cpr-exec migration mode in a subsequent
patch, and contains forward references to cpr-exec mode in the qapi
doc.

No functional change, except that cpr-exec-command is shown by the
'info migrate' command.

Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
  qapi/migration.json            | 21 ++++++++++++++++++---
  migration/migration-hmp-cmds.c | 25 +++++++++++++++++++++++++
  migration/options.c            | 14 ++++++++++++++
  hmp-commands.hx                |  2 +-
  4 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 0fc21f0..79aa528 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -306,6 +306,18 @@ void hmp_info_migrate_capabilities(Monitor *mon, const 
QDict *qdict)
      qapi_free_MigrationCapabilityStatusList(caps);
  }

+static void monitor_print_cpr_exec_command(Monitor *mon, strList *args)

+{
+    monitor_printf(mon, "%s:",
+        MigrationParameter_str(MIGRATION_PARAMETER_CPR_EXEC_COMMAND));
+
+    while (args) {
+        monitor_printf(mon, " %s", args->value);
+        args = args->next;
+    }
+    monitor_printf(mon, "\n");
+}
+
  void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
  {
      MigrationParameters *params;
@@ -435,6 +447,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict 
*qdict)
                                 MIGRATION_PARAMETER_DIRECT_IO),
                             params->direct_io ? "on" : "off");
          }
+
+        assert(params->has_cpr_exec_command);
+        monitor_print_cpr_exec_command(mon, params->cpr_exec_command);
      }

qapi_free_MigrationParameters(params);

@@ -716,6 +731,16 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict 
*qdict)
          p->has_direct_io = true;
          visit_type_bool(v, param, &p->direct_io, &err);
          break;
+    case MIGRATION_PARAMETER_CPR_EXEC_COMMAND: {
+        g_autofree char **strv = g_strsplit(valuestr ?: "", " ", -1);

Perhaps we should use   g_shell_parse_argv() in the HMP case ? IIUC
it should handle quoting for args containing whitespace (as long as
HMP itself has not already mangled that ?).

Thank-you Daniel, that is a good idea.
I verified it works with HMP:

$ build/qemu-system-x86_64 -display none -monitor stdio
(qemu) migrate_set_parameter cpr-exec-command 'a b' c
[0] = a b
[1] = c
(qemu) migrate_set_parameter cpr-exec-command "a b" c
[0] = a b
[1] = c

- Steve