Re: [PATCH v2 28/33] spapr: Remove SpaprIrq::init_kvm hook

[Cédric Le Goater]

On 27/09/2019 07:50, David Gibson wrote:
> This hook is a bit odd.  The only caller is spapr_irq_init_kvm(), but
> it explicitly takes an SpaprIrq *, so it's never really called through the
> current SpaprIrq.  Essentially this is just a way of passing through a
> function pointer so that spapr_irq_init_kvm() can handle some
> configuration and error handling logic without duplicating it between the
> xics and xive reset paths.

yes. There were a few iteration before reaching that state. 
 
> So, make it just take that function pointer.  Because of earlier reworks
> to the KVM connect/disconnect code in the xics and xive backends we can
> also eliminate some wrapper functions and streamline error handling a bit.
> 
> Signed-off-by: David Gibson <address@hidden>

Reviewed-by: Cédric Le Goater <address@hidden>

> ---
>  hw/ppc/spapr_irq.c         | 74 +++++++++++++-------------------------
>  include/hw/ppc/spapr_irq.h |  1 -
>  2 files changed, 25 insertions(+), 50 deletions(-)
> 
> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
> index 561bdbc4de..c6abebc4ef 100644
> --- a/hw/ppc/spapr_irq.c
> +++ b/hw/ppc/spapr_irq.c
> @@ -65,33 +65,35 @@ void spapr_irq_msi_free(SpaprMachineState *spapr, int 
> irq, uint32_t num)
>      bitmap_clear(spapr->irq_map, irq - SPAPR_IRQ_MSI, num);
>  }
>  
> -static void spapr_irq_init_kvm(SpaprMachineState *spapr,
> -                                  SpaprIrq *irq, Error **errp)
> +static int spapr_irq_init_kvm(int (*fn)(SpaprInterruptController *, Error 
> **),
> +                              SpaprInterruptController *intc,
> +                              Error **errp)
>  {
> -    MachineState *machine = MACHINE(spapr);
> +    MachineState *machine = MACHINE(qdev_get_machine());
>      Error *local_err = NULL;
>  
>      if (kvm_enabled() && machine_kernel_irqchip_allowed(machine)) {
> -        irq->init_kvm(spapr, &local_err);
> -        if (local_err && machine_kernel_irqchip_required(machine)) {
> -            error_prepend(&local_err,
> -                          "kernel_irqchip requested but unavailable: ");
> -            error_propagate(errp, local_err);
> -            return;
> -        }
> +        if (fn(intc, &local_err) < 0) {
> +            if (machine_kernel_irqchip_required(machine)) {
> +                error_prepend(&local_err,
> +                              "kernel_irqchip requested but unavailable: ");
> +                error_propagate(errp, local_err);
> +                return -1;
> +            }
>  
> -        if (!local_err) {
> -            return;
> +            /*
> +             * We failed to initialize the KVM device, fallback to
> +             * emulated mode
> +             */
> +            error_prepend(&local_err,
> +                          "kernel_irqchip allowed but unavailable: ");
> +            error_append_hint(&local_err,
> +                              "Falling back to kernel-irqchip=off\n");
> +            warn_report_err(local_err);
>          }
> -
> -        /*
> -         * We failed to initialize the KVM device, fallback to
> -         * emulated mode
> -         */
> -        error_prepend(&local_err, "kernel_irqchip allowed but unavailable: 
> ");
> -        error_append_hint(&local_err, "Falling back to 
> kernel-irqchip=off\n");
> -        warn_report_err(local_err);
>      }
> +
> +    return 0;
>  }
>  
>  /*
> @@ -112,20 +114,7 @@ static int spapr_irq_post_load_xics(SpaprMachineState 
> *spapr, int version_id)
>  
>  static void spapr_irq_reset_xics(SpaprMachineState *spapr, Error **errp)
>  {
> -    Error *local_err = NULL;
> -
> -    spapr_irq_init_kvm(spapr, &spapr_irq_xics, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> -        return;
> -    }
> -}
> -
> -static void spapr_irq_init_kvm_xics(SpaprMachineState *spapr, Error **errp)
> -{
> -    if (kvm_enabled()) {
> -        xics_kvm_connect(SPAPR_INTC(spapr->ics), errp);
> -    }
> +    spapr_irq_init_kvm(xics_kvm_connect, SPAPR_INTC(spapr->ics), errp);
>  }
>  
>  SpaprIrq spapr_irq_xics = {
> @@ -136,7 +125,6 @@ SpaprIrq spapr_irq_xics = {
>  
>      .post_load   = spapr_irq_post_load_xics,
>      .reset       = spapr_irq_reset_xics,
> -    .init_kvm    = spapr_irq_init_kvm_xics,
>  };
>  
>  /*
> @@ -151,7 +139,6 @@ static int spapr_irq_post_load_xive(SpaprMachineState 
> *spapr, int version_id)
>  static void spapr_irq_reset_xive(SpaprMachineState *spapr, Error **errp)
>  {
>      CPUState *cs;
> -    Error *local_err = NULL;
>  
>      CPU_FOREACH(cs) {
>          PowerPCCPU *cpu = POWERPC_CPU(cs);
> @@ -160,9 +147,8 @@ static void spapr_irq_reset_xive(SpaprMachineState 
> *spapr, Error **errp)
>          spapr_xive_set_tctx_os_cam(spapr_cpu_state(cpu)->tctx);
>      }
>  
> -    spapr_irq_init_kvm(spapr, &spapr_irq_xive, &local_err);
> -    if (local_err) {
> -        error_propagate(errp, local_err);
> +    if (spapr_irq_init_kvm(kvmppc_xive_connect,
> +                           SPAPR_INTC(spapr->xive), errp) < 0) {
>          return;
>      }
>  
> @@ -170,13 +156,6 @@ static void spapr_irq_reset_xive(SpaprMachineState 
> *spapr, Error **errp)
>      spapr_xive_mmio_set_enabled(spapr->xive, true);
>  }
>  
> -static void spapr_irq_init_kvm_xive(SpaprMachineState *spapr, Error **errp)
> -{
> -    if (kvm_enabled()) {
> -        kvmppc_xive_connect(SPAPR_INTC(spapr->xive), errp);
> -    }
> -}
> -
>  SpaprIrq spapr_irq_xive = {
>      .nr_xirqs    = SPAPR_NR_XIRQS,
>      .nr_msis     = SPAPR_NR_MSIS,
> @@ -185,7 +164,6 @@ SpaprIrq spapr_irq_xive = {
>  
>      .post_load   = spapr_irq_post_load_xive,
>      .reset       = spapr_irq_reset_xive,
> -    .init_kvm    = spapr_irq_init_kvm_xive,
>  };
>  
>  /*
> @@ -251,7 +229,6 @@ SpaprIrq spapr_irq_dual = {
>  
>      .post_load   = spapr_irq_post_load_dual,
>      .reset       = spapr_irq_reset_dual,
> -    .init_kvm    = NULL, /* should not be used */
>  };
>  
>  
> @@ -682,7 +659,6 @@ SpaprIrq spapr_irq_xics_legacy = {
>  
>      .post_load   = spapr_irq_post_load_xics,
>      .reset       = spapr_irq_reset_xics,
> -    .init_kvm    = spapr_irq_init_kvm_xics,
>  };
>  
>  static void spapr_irq_register_types(void)
> diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
> index c82724fc2b..c947f40571 100644
> --- a/include/hw/ppc/spapr_irq.h
> +++ b/include/hw/ppc/spapr_irq.h
> @@ -85,7 +85,6 @@ typedef struct SpaprIrq {
>  
>      int (*post_load)(SpaprMachineState *spapr, int version_id);
>      void (*reset)(SpaprMachineState *spapr, Error **errp);
> -    void (*init_kvm)(SpaprMachineState *spapr, Error **errp);
>  } SpaprIrq;
>  
>  extern SpaprIrq spapr_irq_xics;
>