Re: [PATCH v2 2/6] qemu_driver: Probe capability before calculating dirty page rate
On Thu, Jan 27, 2022 at 15:25:18 +0800, huangy81(a)chinatelecom.cn wrote:
From: Hyman Huang(黄勇) <huangy81(a)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(a)chinatelecom.cn>
---
src/qemu/qemu_driver.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 0a1ba74..0e8e9b1 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -20647,10 +20647,22 @@ qemuDomainStartDirtyRateCalc(virDomainPtr dom,
virQEMUDriver *driver = dom->conn->privateData;
virDomainObj *vm = NULL;
qemuDomainObjPrivate *priv;
+ g_autoptr(virQEMUCaps) qemucaps = NULL;
int ret = -1;
virCheckFlags(0, -1);
+ if (!(qemucaps = virQEMUCapsCacheLookupDefault(driver->qemuCapsCache,
+ NULL, NULL, NULL, NULL,
+ NULL, NULL, NULL)))
+ return -1;
This is not needed, qemuCaps for a running vm are stored in
'priv->qemuCaps'. In fact it's wrong to not use the stored capabilities.
+
+ if (!virQEMUCapsGet(qemucaps, QEMU_CAPS_CALC_DIRTY_RATE)) {
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",
+ _("QEMU does not support calculating dirty page
rate"));
+ return -1;
+ }
Obviously the code will need to be moved to a place where 'priv' is
already populated.
+
if (seconds < MIN_DIRTYRATE_CALC_PERIOD ||
seconds > MAX_DIRTYRATE_CALC_PERIOD) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
--
1.8.3.1