On 1/28/22 08:35, huangy81@xxxxxxxxxxxxxxx wrote:
> From: Hyman Huang(黄勇) <huangy81@xxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx>
> ---
> 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);
>
This can be done before BeginJob(); because acquiring a job is needless
(and possibly blocking) operation if we know upfront that QEMU doesn't
support what we need. Moving 'priv = vm->privateData' line is perfectly
okay.
Michal
