Re: [Qemu-devel] [PATCH for-2.12 v3 2/3] spapr/rtas: fix reboot of a a SMP TCG guest

[David Gibson]

On Mon, Nov 20, 2017 at 11:03:46AM +0100, Cédric Le Goater wrote:
> Just like for hot unplug CPUs, when a guest is rebooted, the secondary
> CPUs can be awaken by the decrementer and start entering SLOF at the
> same time the boot CPU is.
> 
> To be safe, let's disable on the secondaries all the exceptions which
> can cause an exit while the CPU is in power-saving mode.
> 
> Based on previous work from Nikunj A Dadhania <address@hidden>
> 
> Signed-off-by: Cédric Le Goater <address@hidden>

Reviewed-by: David Gibson <address@hidden>

but not applying pending an update on 1/3.

> ---
> 
> Changes in v3:
> 
>  - used the cpu_ppc_papr_pece_bits() helper 
> 
>  hw/ppc/spapr_cpu_core.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> index 3a4c17401226..4ba8563d49e4 100644
> --- a/hw/ppc/spapr_cpu_core.c
> +++ b/hw/ppc/spapr_cpu_core.c
> @@ -35,6 +35,13 @@ static void spapr_cpu_reset(void *opaque)
>      cs->halted = 1;
>  
>      env->spr[SPR_HIOR] = 0;
> +
> +    /* Disable Power-saving mode Exit Cause exceptions for the CPU.
> +     * This can cause issues when rebooting the guest if a secondary
> +     * is awaken */
> +    if (cs != first_cpu) {
> +        env->spr[SPR_LPCR] &= ~cpu_ppc_papr_pece_bits(env);
> +    }
>  }
>  
>  static void spapr_cpu_destroy(PowerPCCPU *cpu)

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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