Re: [PATCH 3/9] ppc: allow the hdecr timer to be created/destroyed

[Nicholas Piggin]

Excerpts from Cédric Le Goater's message of February 16, 2022 4:36 am:
> On 2/15/22 04:16, Nicholas Piggin wrote:
>> Machines which don't emulate the HDEC facility are able to use the
>> timer for something else. Provide functions to start and stop the
>> hdecr timer.
>>
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>   hw/ppc/ppc.c         | 20 ++++++++++++++++++++
>>   include/hw/ppc/ppc.h |  3 +++
>>   2 files changed, 23 insertions(+)
>> 
>> diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
>> index c6dfc5975f..4bfd413c7f 100644
>> --- a/hw/ppc/ppc.c
>> +++ b/hw/ppc/ppc.c
>> @@ -1083,6 +1083,26 @@ clk_setup_cb cpu_ppc_tb_init (CPUPPCState *env, 
>> uint32_t freq)
>>       return &cpu_ppc_set_tb_clk;
>>   }
>>   
>> +void cpu_ppc_hdecr_init (CPUPPCState *env)
> 
> checkpatch will complain ^

It did but I thouht I would keep to existing style. I'll change it.

> 
>> +{
>> +    PowerPCCPU *cpu = env_archcpu(env);
>> +
>> +    assert(env->tb_env->hdecr_timer == NULL);
>> +
>> +    env->tb_env->hdecr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, 
>> &cpu_ppc_hdecr_cb,
>> +                                                 cpu);
>> +}
>> +
> 
> I am not convinced. Can't we start and stop the hdecr on demand ?

timer_mod() for existing hdecr_timer when we do ppc_store_hdecr, but
that shouldn't be used elsewhere in pseries except for nested HV.

Thanks,
Nick