Re: [Qemu-devel] [PATCH] hw: add .min_cpus and .default_cpus fields to machine_class

[Richard Henderson]

On 11/06/2017 09:13 PM, Emilio G. Cota wrote:
> Subject: [PATCH] qom: move CPUClass.tcg_initialize to a global
> 
> 55c3cee ("qom: Introduce CPUClass.tcg_initialize", 2017-10-24)
> introduces a per-CPUClass bool that we check so that the target CPU
> is initialized for TCG only once. This works well except when
> we end up creating more than one CPUClass, in which case we end
> up incorrectly initializing TCG more than once, i.e. once for
> each CPUClass.
> 
> This can be replicated with:
>   $ aarch64-softmmu/qemu-system-aarch64 -machine xlnx-zcu102 -smp 6 \
>       -global driver=xlnx,,zynqmp,property=has_rpu,value=on
> In this case the class name of the "RPUs" is prefixed by "cortex-r5-",
> whereas the "regular" CPUs are prefixed by "cortex-a53-". This
> results in two CPUClass instances being created.
> 
> Fix it by introducing a static variable, so that only the first
> target CPU being initialized will initialize the target-dependent
> part of TCG, regardless of CPUClass instances.

Hah!

So, I had been thinking of the xylinx ARM + Microblaze case, where we really do
need two different initializations.  I never imagined that two different ARM
parts had different CPUClasses.

So I guess it's my initial patch that unified this that's more buggy than not.


r~