Re: [PATCH v2 2/6] qemu_driver: Probe capability before calculating dirty page rate

[Hyman Huang <huangy81@xxxxxxxxxxxxxxx>]

在 2022/1/27 16:23, Peter Krempa 写道:
> On Thu, Jan 27, 2022 at 15:25:18 +0800, 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 | 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