Re: [Qemu-devel] [Qemu-ppc] [PATCH] ppc/spapr: Add H_PROD and H_CONFER

[Greg Kurz]

On Thu, 11 Apr 2019 08:34:08 +0200
Cédric Le Goater <address@hidden> wrote:

> From: Benjamin Herrenschmidt <address@hidden>
> 
> H_PROD should be fully functional, H_CEDE is modified to
> ignore a proded CPU. H_CONFER is a stub to avoid returning
> an error.
> 
> Signed-off-by: Benjamin Herrenschmidt <address@hidden>
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>  target/ppc/cpu.h     |  3 +++
>  hw/ppc/spapr_hcall.c | 37 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 40 insertions(+)
> 
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index 42eadc4b7997..07cea7268c0c 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -1141,6 +1141,9 @@ struct CPUPPCState {
>       * sreset), so flag this here.
>       */
>      bool resume_as_sreset;
> +
> +    /* Used by SPAPR for H_CEDE/H_PROD */
> +    bool prodded;
>  #endif
>  
>      /* Those resources are used only during code translation */
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 8a736797b9bf..be8044a92f2f 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1057,6 +1057,11 @@ static target_ulong h_cede(PowerPCCPU *cpu, 
> SpaprMachineState *spapr,
>  
>      env->msr |= (1ULL << MSR_EE);
>      hreg_compute_hflags(env);
> +    if (env->prodded) {
> +        env->prodded = false;
> +        return H_SUCCESS;
> +    }
> +

The "H_CEDE is modified to ignore a proded CPU" sentence in the changelog
is slightly inaccurate since the "prod" bit is reset, as described in
LoPAPR v1.1 14.11.3.3 H_CEDE.

Appart from that LGTM.

Reviewed-by: Greg Kurz <address@hidden>

>      if (!cpu_has_work(cs)) {
>          cs->halted = 1;
>          cs->exception_index = EXCP_HLT;
> @@ -1065,6 +1070,36 @@ static target_ulong h_cede(PowerPCCPU *cpu, 
> SpaprMachineState *spapr,
>      return H_SUCCESS;
>  }
>  
> +static void spapr_do_wakeup_on_cpu(CPUState *cs, run_on_cpu_data data)
> +{
> +    cs->halted = 0;
> +    cs->exception_index = -1;
> +}
> +
> +static target_ulong h_prod(PowerPCCPU *cpu, SpaprMachineState *spapr,
> +                           target_ulong opcode, target_ulong *args)
> +{
> +    target_ulong target = args[0];
> +    CPUPPCState *env;
> +
> +    cpu = spapr_find_cpu(target);
> +    if (cpu) {
> +        env = &cpu->env;
> +        env->prodded = true;
> +        run_on_cpu(CPU(cpu), spapr_do_wakeup_on_cpu, RUN_ON_CPU_NULL);
> +    } else {
> +        return H_PARAMETER;
> +    }
> +    return H_SUCCESS;
> +}
> +
> +static target_ulong h_confer(PowerPCCPU *cpu, SpaprMachineState *spapr,
> +                             target_ulong opcode, target_ulong *args)
> +{
> +    /* Do nothing (supposed to confer timeslice). */
> +    return H_SUCCESS;
> +}
> +
>  static target_ulong h_rtas(PowerPCCPU *cpu, SpaprMachineState *spapr,
>                             target_ulong opcode, target_ulong *args)
>  {
> @@ -1860,6 +1895,8 @@ static void hypercall_register_types(void)
>      /* hcall-splpar */
>      spapr_register_hypercall(H_REGISTER_VPA, h_register_vpa);
>      spapr_register_hypercall(H_CEDE, h_cede);
> +    spapr_register_hypercall(H_PROD, h_prod);
> +    spapr_register_hypercall(H_CONFER, h_confer);
>      spapr_register_hypercall(H_SIGNAL_SYS_RESET, h_signal_sys_reset);
>  
>      /* processor register resource access h-calls */