[Qemu-devel] [PATCH] numa: improve cpu hotplug error message with a wrong node-id

[Qemu-devel] [PATCH] numa: improve cpu hotplug error message with a wrong node-id

[Laurent Vivier]

On pseries, core-ids are strongly binded to a node-id by the command
line option. If a user tries to add a CPU to the wrong node, he has
an error but it is not really helpful:

  qemu-system-ppc64 ... -smp 1,maxcpus=64,cores=1,threads=1,sockets=1 \
                        -numa node,nodeid=0 -numa node,nodeid=1 ...

  (qemu) device_add power9_v2.0-spapr-cpu-core,core-id=30,node-id=1
  Error: node-id=1 must match numa node specified with -numa option

This patch improves this error message by giving to the user the good
node-id to use with the core-id he's providing:

  Error: core-id 30 can only be plugged into node-id 0

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 numa.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/numa.c b/numa.c
index 3875e1efda3a..c419c5b5b8ee 100644
--- a/numa.c
+++ b/numa.c
@@ -470,8 +470,9 @@ void numa_cpu_pre_plug(const CPUArchId *slot, DeviceState *dev, Error **errp)
                                     "node-id", errp);
         }
     } else if (node_id != slot->props.node_id) {
-        error_setg(errp, "node-id=%d must match numa node specified "
-                   "with -numa option", node_id);
+        error_setg(errp,
+                   "core-id %"PRId64" can only be plugged into node-id %"PRId64,
+                   slot->props.core_id, slot->props.node_id);
     }
 }
 
-- 
2.20.1

Re: [Qemu-devel] [PATCH] numa: improve cpu hotplug error message with a wrong node-id

[Eduardo Habkost]

On Mon, May 20, 2019 at 05:29:21PM +0200, Laurent Vivier wrote:
> On pseries, core-ids are strongly binded to a node-id by the command
> line option. If a user tries to add a CPU to the wrong node, he has
> an error but it is not really helpful:
> 
>   qemu-system-ppc64 ... -smp 1,maxcpus=64,cores=1,threads=1,sockets=1 \
>                         -numa node,nodeid=0 -numa node,nodeid=1 ...
> 
>   (qemu) device_add power9_v2.0-spapr-cpu-core,core-id=30,node-id=1
>   Error: node-id=1 must match numa node specified with -numa option
> 
> This patch improves this error message by giving to the user the good
> node-id to use with the core-id he's providing:
> 
>   Error: core-id 30 can only be plugged into node-id 0

Why just core-id?  What about the other fields at slot->props?

> 
> Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> ---
>  numa.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/numa.c b/numa.c
> index 3875e1efda3a..c419c5b5b8ee 100644
> --- a/numa.c
> +++ b/numa.c
> @@ -470,8 +470,9 @@ void numa_cpu_pre_plug(const CPUArchId *slot, DeviceState *dev, Error **errp)
>                                      "node-id", errp);
>          }
>      } else if (node_id != slot->props.node_id) {
> -        error_setg(errp, "node-id=%d must match numa node specified "
> -                   "with -numa option", node_id);
> +        error_setg(errp,
> +                   "core-id %"PRId64" can only be plugged into node-id %"PRId64,
> +                   slot->props.core_id, slot->props.node_id);
>      }
>  }
>  
> -- 
> 2.20.1
> 

-- 
Eduardo