[PATCH v3 3/5] qemu: Rename qemuMonitorCommandWithHandler as qemuMonitorText*

[Jiri Denemark <jdenemar@xxxxxxxxxx>]

qemu driver in libvirt gained support for creating domain snapshots
almost a year ago in libvirt 0.8.0. Since then we enabled QMP support
for qemu >= 0.13.0 but QMP equivalents of {save,load,del}vm commands are
not implemented in current qemu (0.14.0) so the domain snapshot support
is not very useful.

This patch detects when the appropriate QMP command is not implemented
and tries to use human-monitor-command (aka HMP passthrough) to run
it's HMP equivalent.
---
Version 3:
- separated from HMP passthrough infrastructure
- implement HMP fallback for {load,del}vm in addition to savevm

 src/qemu/qemu_monitor_json.c |   40 +++++++++++++++++++++++++++++++---------
 1 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 918591e..d97dc68 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <sys/time.h>
 
+#include "qemu_monitor_text.h"
 #include "qemu_monitor_json.h"
 #include "qemu_command.h"
 #include "memory.h"
@@ -2451,11 +2452,18 @@ int qemuMonitorJSONCreateSnapshot(qemuMonitorPtr mon, const char *name)
     if (!cmd)
         return -1;
 
-    ret = qemuMonitorJSONCommand(mon, cmd, &reply);
+    if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
+        goto cleanup;
 
-    if (ret == 0)
-        ret = qemuMonitorJSONCheckError(cmd, reply);
+    if (qemuMonitorJSONHasError(reply, "CommandNotFound")) {
+        VIR_DEBUG0("savevm command not found, trying HMP");
+        ret = qemuMonitorTextCreateSnapshot(mon, name);
+        goto cleanup;
+    }
 
+    ret = qemuMonitorJSONCheckError(cmd, reply);
+
+cleanup:
     virJSONValueFree(cmd);
     virJSONValueFree(reply);
     return ret;
@@ -2473,11 +2481,18 @@ int qemuMonitorJSONLoadSnapshot(qemuMonitorPtr mon, const char *name)
     if (!cmd)
         return -1;
 
-    ret = qemuMonitorJSONCommand(mon, cmd, &reply);
+    if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
+        goto cleanup;
 
-    if (ret == 0)
-        ret = qemuMonitorJSONCheckError(cmd, reply);
+    if (qemuMonitorJSONHasError(reply, "CommandNotFound")) {
+        VIR_DEBUG0("loadvm command not found, trying HMP");
+        ret = qemuMonitorTextLoadSnapshot(mon, name);
+        goto cleanup;
+    }
+
+    ret = qemuMonitorJSONCheckError(cmd, reply);
 
+cleanup:
     virJSONValueFree(cmd);
     virJSONValueFree(reply);
     return ret;
@@ -2495,11 +2510,18 @@ int qemuMonitorJSONDeleteSnapshot(qemuMonitorPtr mon, const char *name)
     if (!cmd)
         return -1;
 
-    ret = qemuMonitorJSONCommand(mon, cmd, &reply);
+    if ((ret = qemuMonitorJSONCommand(mon, cmd, &reply)) < 0)
+        goto cleanup;
 
-    if (ret == 0)
-        ret = qemuMonitorJSONCheckError(cmd, reply);
+    if (qemuMonitorJSONHasError(reply, "CommandNotFound")) {
+        VIR_DEBUG0("delvm command not found, trying HMP");
+        ret = qemuMonitorTextDeleteSnapshot(mon, name);
+        goto cleanup;
+    }
+
+    ret = qemuMonitorJSONCheckError(cmd, reply);
 
+cleanup:
     virJSONValueFree(cmd);
     virJSONValueFree(reply);
     return ret;
-- 
1.7.4.1

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