Re: [PATCH] hw/ppc/spapr: Test whether TCG is enabled with tcg_enabled()

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

On 20/6/23 16:48, Greg Kurz wrote:
> On Tue, 20 Jun 2023 09:55:49 +0200
> Claudio Fontana <cfontana@suse.de> wrote:
> 
>> On 6/20/23 09:48, Philippe Mathieu-Daudé wrote:
>>> Although the PPC target only supports the TCG and KVM
>>> accelerators, QEMU supports more. We can no assume that
>>> '!kvm == tcg', so test for the correct accelerator. This
>>> also eases code review, because here we don't care about
>>> KVM, we really want to test for TCG.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>
>> I don't remember anymore, but what about qtest ? It is usually the forgotten case in these kind of tests... so much complexity :-)

Good to think about this, since such changes indeed usually break,
qtests :)

> This check was added with TCG in mind because it is a known limitation.
> I don't see any reason to prevent qtest from being used with the rest
> of this function though.

We don't have any CPU core when using qtest accelerator, so this
check is irrelevant IMHO (not reachable with '-accel qtest').

>>> ---
>>>   hw/ppc/spapr.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>> index dcb7f1c70a..c4b666587b 100644
>>> --- a/hw/ppc/spapr.c
>>> +++ b/hw/ppc/spapr.c
>>> @@ -2524,7 +2524,7 @@ static void spapr_set_vsmt_mode(SpaprMachineState *spapr, Error **errp)
>>>       int ret;
>>>       unsigned int smp_threads = ms->smp.threads;
>>>   
>>> -    if (!kvm_enabled() && (smp_threads > 1)) {
>>> +    if (tcg_enabled() && (smp_threads > 1)) {
> 
> Bonjour Philippe,
> 
> Please drop the unneeded parens in the second check.

I wanted to do that but then thought someone would ask me to do one
change at once ;)

> With this fixed,
> 
> Reviewed-by: Greg Kurz <groug@kaod.org>

Thanks!