diff mbox series

[for-6.0,5/9] spapr: Simplify error path of spapr_core_plug()

Message ID 20201120234208.683521-6-groug@kaod.org
State New
Headers show
Series spapr: Perform hotplug sanity checks at pre-plug | expand

Commit Message

Greg Kurz Nov. 20, 2020, 11:42 p.m. UTC
spapr_core_pre_plug() already guarantees that the slot for the given core
ID is available. It is thus safe to assume that spapr_find_cpu_slot()
returns a slot during plug. Turn the error path into an assertion.
It is also safe to assume that no device is attached to the corresponding
DRC and that spapr_drc_attach() shouldn't fail.

Pass &error_abort to spapr_drc_attach() and simplify error handling.

Signed-off-by: Greg Kurz <groug@kaod.org>
---
 hw/ppc/spapr.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

Comments

David Gibson Nov. 23, 2020, 5:13 a.m. UTC | #1
On Sat, Nov 21, 2020 at 12:42:04AM +0100, Greg Kurz wrote:
> spapr_core_pre_plug() already guarantees that the slot for the given core
> ID is available. It is thus safe to assume that spapr_find_cpu_slot()
> returns a slot during plug. Turn the error path into an assertion.
> It is also safe to assume that no device is attached to the corresponding
> DRC and that spapr_drc_attach() shouldn't fail.
> 
> Pass &error_abort to spapr_drc_attach() and simplify error handling.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>

Applied to ppc-for-6.0, thanks.

> ---
>  hw/ppc/spapr.c | 21 ++++++++++-----------
>  1 file changed, 10 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index da7586f548df..cfca033c7b14 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -3739,8 +3739,7 @@ int spapr_core_dt_populate(SpaprDrc *drc, SpaprMachineState *spapr,
>      return 0;
>  }
>  
> -static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
> -                            Error **errp)
> +static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev)
>  {
>      SpaprMachineState *spapr = SPAPR_MACHINE(OBJECT(hotplug_dev));
>      MachineClass *mc = MACHINE_GET_CLASS(spapr);
> @@ -3755,20 +3754,20 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
>      int i;
>  
>      core_slot = spapr_find_cpu_slot(MACHINE(hotplug_dev), cc->core_id, &index);
> -    if (!core_slot) {
> -        error_setg(errp, "Unable to find CPU core with core-id: %d",
> -                   cc->core_id);
> -        return;
> -    }
> +    g_assert(core_slot); /* Already checked in spapr_core_pre_plug() */
> +
>      drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU,
>                            spapr_vcpu_id(spapr, cc->core_id));
>  
>      g_assert(drc || !mc->has_hotpluggable_cpus);
>  
>      if (drc) {
> -        if (!spapr_drc_attach(drc, dev, errp)) {
> -            return;
> -        }
> +        /*
> +         * spapr_core_pre_plug() already buys us this is a brand new
> +         * core being plugged into a free slot. Nothing should already
> +         * be attached to the corresponding DRC.
> +         */
> +        spapr_drc_attach(drc, dev, &error_abort);
>  
>          if (hotplugged) {
>              /*
> @@ -3981,7 +3980,7 @@ static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
>          spapr_memory_plug(hotplug_dev, dev);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_CPU_CORE)) {
> -        spapr_core_plug(hotplug_dev, dev, errp);
> +        spapr_core_plug(hotplug_dev, dev);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_PCI_HOST_BRIDGE)) {
>          spapr_phb_plug(hotplug_dev, dev, errp);
>      } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_TPM_PROXY)) {
diff mbox series

Patch

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index da7586f548df..cfca033c7b14 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3739,8 +3739,7 @@  int spapr_core_dt_populate(SpaprDrc *drc, SpaprMachineState *spapr,
     return 0;
 }
 
-static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
-                            Error **errp)
+static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev)
 {
     SpaprMachineState *spapr = SPAPR_MACHINE(OBJECT(hotplug_dev));
     MachineClass *mc = MACHINE_GET_CLASS(spapr);
@@ -3755,20 +3754,20 @@  static void spapr_core_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     int i;
 
     core_slot = spapr_find_cpu_slot(MACHINE(hotplug_dev), cc->core_id, &index);
-    if (!core_slot) {
-        error_setg(errp, "Unable to find CPU core with core-id: %d",
-                   cc->core_id);
-        return;
-    }
+    g_assert(core_slot); /* Already checked in spapr_core_pre_plug() */
+
     drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU,
                           spapr_vcpu_id(spapr, cc->core_id));
 
     g_assert(drc || !mc->has_hotpluggable_cpus);
 
     if (drc) {
-        if (!spapr_drc_attach(drc, dev, errp)) {
-            return;
-        }
+        /*
+         * spapr_core_pre_plug() already buys us this is a brand new
+         * core being plugged into a free slot. Nothing should already
+         * be attached to the corresponding DRC.
+         */
+        spapr_drc_attach(drc, dev, &error_abort);
 
         if (hotplugged) {
             /*
@@ -3981,7 +3980,7 @@  static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
         spapr_memory_plug(hotplug_dev, dev);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_CPU_CORE)) {
-        spapr_core_plug(hotplug_dev, dev, errp);
+        spapr_core_plug(hotplug_dev, dev);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_PCI_HOST_BRIDGE)) {
         spapr_phb_plug(hotplug_dev, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_SPAPR_TPM_PROXY)) {