Re: [Qemu-devel] [RFC PATCH] qdev: Mark devices as non-hotpluggable by default

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 20 Sep 2017 18:10:48 +0200
Thomas Huth <thuth@redhat.com> wrote:

> On 20.09.2017 13:17, Thomas Huth wrote:
> > On 20.09.2017 12:57, Marcel Apfelbaum wrote:  
> >> On 20/09/2017 13:07, Peter Maydell wrote:  
> [...]
> >>> Is it possible to hack together some kind of test code that
> >>> can give us a list of the devices compiled in that have
> >>> hotpluggable enabled? Then we could compare before and
> >>> after to see which devices we've changed.
> >>>  
> >>
> >> Eduardo came up with some cool automated tests not long ago.
> >> Eduardo, can your tests help?  
> > 
> > You mean the scripts/device-crash-test script? That's only for
> > cold-plugging ... but I could maybe use the device_add HMP test (see
> > https://lists.gnu.org/archive/html/qemu-devel/2017-09/msg00817.html ) to
> > exercise the hotplugging of all devices and add some debug code to
> > qdev_device_add() to see which devices are dc->hotpluggable and have a
> > hotplug handler at the same time... I'll give it a try.  
> 
> Ok, done that now, and it looks like I missed devices of type
> TYPE_X86_CPU and TYPE_S390_CPU at least... Unlike the ppc64 CPUs, they
> are not derived from TYPE_CPU_CORE, but from TYPE_CPU ... is that on
> purpose? I thought hot-pluggable CPUs would need to be derived from
> TYPE_CPU_CORE... well, maybe I just understood that wrong.
> I'll send a new version of my patch.
cpu hotplug on x86 existed before ppc started to support it and
hotplug is done at thread level there. core was introduced later
for ppc as guest expects hotplugged cpu in core granularity.

So as you noticed some leaf CPU types are indeed hotpluggble.


> 
>  Thomas