[libvirt] [PATCH 2/3] setting QEMU_CAPS_WAKEUP_SUSPEND_SUPPORT qemu capability

[Daniel Henrique Barboza]

QEMU_CAPS_WAKEUP_SUSPEND_SUPPORT is a bool that represents the value
of the wakeup-suspend-support flag of the new query-current-machine
QMP API, available in QEMU 4.0.

The flag is set in qemuProcessLaunch, using a new function called
qemuProcessSetupWakeupSuspendSupport. This function checks first
if the QEMU process has support for the new API, which is reflected
by the QEMU_CAPS_QUERY_CURRENT_MACHINE cap. If positive, query it
and set QEMU_CAPS_WAKEUP_SUSPEND_SUPPORT with the current value
of wakeup-suspend-support.
---
 src/qemu/qemu_monitor.c      |  8 ++++++++
 src/qemu/qemu_monitor.h      |  3 +++
 src/qemu/qemu_monitor_json.c | 35 +++++++++++++++++++++++++++++++++
 src/qemu/qemu_monitor_json.h |  4 ++++
 src/qemu/qemu_process.c      | 38 ++++++++++++++++++++++++++++++++++++
 5 files changed, 88 insertions(+)

diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index babcbde878..fc6dc2197a 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -4472,3 +4472,11 @@ qemuMonitorGetPRManagerInfo(qemuMonitorPtr mon,
     virHashFree(info);
     return ret;
 }
+
+int
+qemuMonitorGetWakeupSuspendSupport(qemuMonitorPtr mon, bool *enabled)
+{
+    QEMU_CHECK_MONITOR(mon);
+
+    return qemuMonitorJSONGetWakeupSuspendSupport(mon, enabled);
+}
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 086195ff98..62074c1acb 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -1220,4 +1220,7 @@ struct _qemuMonitorPRManagerInfo {
 int qemuMonitorGetPRManagerInfo(qemuMonitorPtr mon,
                                 virHashTablePtr *retinfo);
 
+int qemuMonitorGetWakeupSuspendSupport(qemuMonitorPtr mon,
+                                       bool *enabled);
+
 #endif /* LIBVIRT_QEMU_MONITOR_H */
diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
index 743a88b914..16d34fb217 100644
--- a/src/qemu/qemu_monitor_json.c
+++ b/src/qemu/qemu_monitor_json.c
@@ -8452,3 +8452,38 @@ qemuMonitorJSONGetPRManagerInfo(qemuMonitorPtr mon,
     return ret;
 
 }
+
+int
+qemuMonitorJSONGetWakeupSuspendSupport(qemuMonitorPtr mon, bool *enabled)
+{
+    int ret = -1;
+    virJSONValuePtr cmd, data;
+    virJSONValuePtr reply = NULL;
+
+    if (!(cmd = qemuMonitorJSONMakeCommand("query-current-machine",
+                                           NULL)))
+        return -1;
+
+    if (qemuMonitorJSONCommand(mon, cmd, &reply) < 0)
+        goto cleanup;
+
+    if (qemuMonitorJSONCheckReply(cmd, reply, VIR_JSON_TYPE_OBJECT) < 0)
+        goto cleanup;
+
+    data = virJSONValueObjectGetObject(reply, "return");
+
+    if (virJSONValueObjectGetBoolean(data, "wakeup-suspend-support",
+                                     enabled)) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("missing wakeup-suspend-support in "
+                         "query-current-machine response"));
+        goto cleanup;
+    }
+
+    ret = 0;
+
+ cleanup:
+    virJSONValueFree(cmd);
+    virJSONValueFree(reply);
+    return ret;
+}
diff --git a/src/qemu/qemu_monitor_json.h b/src/qemu/qemu_monitor_json.h
index c10513da15..ede828d622 100644
--- a/src/qemu/qemu_monitor_json.h
+++ b/src/qemu/qemu_monitor_json.h
@@ -576,4 +576,8 @@ int qemuMonitorJSONGetPRManagerInfo(qemuMonitorPtr mon,
                                     virHashTablePtr info)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
+int qemuMonitorJSONGetWakeupSuspendSupport(qemuMonitorPtr mon,
+                                           bool *enabled)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+
 #endif /* LIBVIRT_QEMU_MONITOR_JSON_H */
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index dc7317b723..71984714de 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -6449,6 +6449,41 @@ qemuProcessSetupDiskThrottlingBlockdev(virQEMUDriverPtr driver,
     return ret;
 }
 
+/**
+ * qemuProcessSetupWakeupSuspendSupport:
+ *
+ * Sets up QEMU_CAPS_WAKEUP_SUSPEND_SUPPORT in case QEMU has support
+ * for the query-current-machine QMP API. This can be verified by
+ * checking for the QEMU_CAPS_QUERY_CURRENT_MACHINE cap.
+ */
+static int
+qemuProcessSetupWakeupSuspendSupport(virQEMUDriverPtr driver,
+                                       virDomainObjPtr vm,
+                                       qemuDomainAsyncJob asyncJob)
+{
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    bool enabled;
+    int ret = -1;
+
+    if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_QUERY_CURRENT_MACHINE))
+        return 0;
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+        return -1;
+
+    if (qemuMonitorGetWakeupSuspendSupport(qemuDomainGetMonitor(vm), &enabled) < 0)
+        goto cleanup;
+
+    if (enabled)
+        virQEMUCapsSet(priv->qemuCaps, QEMU_CAPS_WAKEUP_SUSPEND_SUPPORT);
+
+    ret = 0;
+
+ cleanup:
+    if (qemuDomainObjExitMonitor(driver, vm) < 0)
+        ret = -1;
+    return ret;
+}
 
 /**
  * qemuProcessLaunch:
@@ -6777,6 +6812,9 @@ qemuProcessLaunch(virConnectPtr conn,
         qemuProcessAutoDestroyAdd(driver, vm, conn) < 0)
         goto cleanup;
 
+    if (qemuProcessSetupWakeupSuspendSupport(driver, vm, asyncJob) < 0)
+        goto cleanup;
+
     ret = 0;
 
  cleanup:
-- 
2.20.1