[PATCH v3 2/7] qemu_driver: Probe capability before calculating dirty page rate

[huangy81 at chinatelecom.cn]

From: Hyman Huang(黄勇) <huangy81 at chinatelecom.cn>

Probing QEMU_CAPS_CALC_DIRTY_RATE capability in advance
in case of failure when calculating dirty page rate.

Signed-off-by: Hyman Huang(黄勇) <huangy81 at chinatelecom.cn>
---
 src/qemu/qemu_driver.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 0a1ba74..c8ee897 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -20679,6 +20679,12 @@ qemuDomainStartDirtyRateCalc(virDomainPtr dom,
     VIR_DEBUG("Calculate dirty rate in next %d seconds", seconds);
 
     priv = vm->privateData;
+    if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_CALC_DIRTY_RATE)) {
+        virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+                       _("QEMU does not support calculating dirty page rate"));
+        goto endjob;
+    }
+
     qemuDomainObjEnterMonitor(driver, vm);
     ret = qemuMonitorStartDirtyRateCalc(priv->mon, seconds);
 
-- 
1.8.3.1