Re: [qemu-s390x] [PATCH v2 7/7] s390x/tcg: fix CPU hotplug with single-threaded TCG

[Thomas Huth]

On 20.06.2018 12:08, David Hildenbrand wrote:
> run_on_cpu() doesn't seem to work reliably until the CPU has been fully
> created if the single-threaded TCG main loop is already running.
> 
> Therefore, let's use run_on_cpu() for KVM only - KVM requires it due to
> the initial CPU reset ioctl.
> 
> Signed-off-by: David Hildenbrand <address@hidden>
> ---
>  target/s390x/cpu.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index 40d6980229..7536dd0f03 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -218,11 +218,12 @@ static void s390_cpu_realizefn(DeviceState *dev, Error 
> **errp)
>  #endif
>      s390_cpu_gdb_init(cs);
>      qemu_init_vcpu(cs);
> -#if !defined(CONFIG_USER_ONLY)
> -    run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
> -#else
> -    cpu_reset(cs);
> -#endif
> +
> +    if (kvm_enabled()) {
> +        run_on_cpu(cs, s390_do_cpu_full_reset, RUN_ON_CPU_NULL);
> +    } else {
> +        cpu_reset(cs);
> +    }

Could you please add a comment with the information from the patch
description before that code? Otherwise, I guess everybody who only
looks at the code (and not at the git history) will be quite confused
about this, too.

 Thomas