On Tue, 28 Jul 2020 21:51:33 -0300 Thiago Jung Bauermann <bauer...@linux.ibm.com> wrote:
> Hi, > > Cornelia Huck <coh...@redhat.com> writes: > > > On Wed, 22 Jul 2020 23:56:57 -0300 > > Thiago Jung Bauermann <bauer...@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 <bauer...@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. Experimented a bit with it again. There's a pause when switching from the bios to the kernel (after the load reset normal has been done, I guess), which is always there, but seems to get more noticeable with this patch (varying wildly, but seems longer on average.) Hard to pin down, and I don't really see a reason why that should happen, as we should end up with halted == 1 in any case. Might still be a fluke, even though I see it both on my laptop and on an LPAR (when running under tcg; not seen under kvm, which is much faster anyway.) > > I tried today setting up a TCG guest, but didn't have success yet. > Will try some more tomorrow. > I'm also looking a bit at the other s390 folks :)
