Re: [PATCH 2/3] plugins: Free CPUPluginState before destroying vCPU state

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 6/6/24 23:14, Pierrick Bouvier wrote:
> On 6/6/24 05:40, Philippe Mathieu-Daudé wrote:
>> cpu::plugin_state is allocated in cpu_common_initfn() when
>> the vCPU state is created. Release it in cpu_common_finalize()
>> when we are done.
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   include/qemu/plugin.h | 3 +++
>>   hw/core/cpu-common.c  | 5 +++++
>>   2 files changed, 8 insertions(+)
>>
>> diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h
>> index bc5aef979e..af5f9db469 100644
>> --- a/include/qemu/plugin.h
>> +++ b/include/qemu/plugin.h
>> @@ -149,6 +149,9 @@ struct CPUPluginState {
>>   /**
>>    * qemu_plugin_create_vcpu_state: allocate plugin state
>> + *
>> + * The returned data must be released with g_free()
>> + * when no longer required.
>>    */
>>   CPUPluginState *qemu_plugin_create_vcpu_state(void);
>> diff --git a/hw/core/cpu-common.c b/hw/core/cpu-common.c
>> index bf1a7b8892..cd15402552 100644
>> --- a/hw/core/cpu-common.c
>> +++ b/hw/core/cpu-common.c
>> @@ -283,6 +283,11 @@ static void cpu_common_finalize(Object *obj)
>>   {
>>       CPUState *cpu = CPU(obj);
>> +#ifdef CONFIG_PLUGIN
>> +    if (tcg_enabled()) {
>> +        g_free(cpu->plugin_state);
>> +    }
>> +#endif
>>       g_array_free(cpu->gdb_regs, TRUE);
>>       qemu_lockcnt_destroy(&cpu->in_ioctl_lock);
>>       qemu_mutex_destroy(&cpu->work_mutex);
> 
> To ensure I get it right, order of cpu init/deinit is:
> - init
> - realize
> - unrealize
> - finalize
> Is that correct?

Yes, this is valid for all QDev (CPU is based on it).

+ init: allocate state, expose configurable properties
. user configure properties
+ realize: consume properties to tune the object
+ reset: set default values
. object is used
+ unrealize: undo stuff from realize because the object
   might be realized again (unplug - plug)
+ finalize: release resources

See 
https://lore.kernel.org/qemu-devel/20240209123226.32576-1-philmd@linaro.org/

> Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>

Thanks!