Re: [Qemu-devel] [RFC PATCH] target-arm/psci.c: wake up sleeping CPUs (MTTCG)

[Paolo Bonzini <pbonzini@redhat.com>]

On 24/06/2015 17:34, Alex Bennée wrote:
> Testing with Alexander's bare metal syncronisation tests fails in MTTCG
> leaving one CPU spinning forever waiting for the second CPU to wake up.
> We simply need to poke the halt_cond once we have processed the PSCI
> power on call.
> 
> Tested-by: Alex Bennée <alex.bennee@linaro.org>
> CC: Alexander Spyridakis <a.spyridakis@virtualopensystems.com>
> 
> ---
> TODO
>   - exactly how does the vexpress wake up it's sleeping CPUs?
> ---
>  target-arm/psci.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/target-arm/psci.c b/target-arm/psci.c
> index d8fafab..661ff28 100644
> --- a/target-arm/psci.c
> +++ b/target-arm/psci.c
> @@ -196,6 +196,8 @@ void arm_handle_psci_call(ARMCPU *cpu)
>          }
>          target_cpu_class->set_pc(target_cpu_state, entry);
>  
> +        qemu_cond_signal(target_cpu_state->halt_cond);

That's called qemu_cpu_kick(target_cpu_state). :)  The patch should be
acceptable now upstream, I think.

Paolo

>          ret = 0;
>          break;
>      case QEMU_PSCI_0_1_FN_CPU_OFF:
>