Re: [RFC PATCH v3 8/8] target/s390x: Use start-powered-off CPUState property

[Thiago Jung Bauermann]

Hi,

Cornelia Huck <cohuck@redhat.com> writes:

> On Wed, 22 Jul 2020 23:56:57 -0300
> Thiago Jung Bauermann <bauerman@linux.ibm.com> wrote:
>
>> Instead of setting CPUState::halted to 1 in s390_cpu_initfn(), use the
>> start-powered-off property which makes cpu_common_reset() initialize it
>> to 1 in common code.
>> 
>> Note that this changes behavior by setting cs->halted to 1 on reset, which
>> didn't happen before.
>
> I think that should be fine, as we change the cpu state to STOPPED in
> the reset function, which sets halted to 1.

Nice, thanks for checking.

>> 
>> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
>> ---
>>  target/s390x/cpu.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> NB: I was only able to test that this patch builds. I wasn't able to
>> run it.
>
> No noticeable difference under kvm, but running under tcg seems a bit
> more sluggish than usual, and I saw some pausing on reboot (after the
> bios handover to the kernel). Not sure if it were just flukes on my
> laptop, would appreciate if someone else could give it a go.

I tried today setting up a TCG guest, but didn't have success yet.
Will try some more tomorrow.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center