Re: [Qemu-devel] [PATCH 1/3] cpu: Make the mapping of CPUs and NUMA nodes in cpu_common_realizefn

[Eduardo Habkost <ehabkost@redhat.com>]

On Wed, Jan 18, 2017 at 08:40:05PM +0800, Dou Liyang wrote:
> Current default way of seting the CPUState::numa_node might be wrong
> in case on cold/hot-plug CPUs. Making the users confused why the
> NUMA info is different beetween the guests and monitor.
> 
> Make the mapping of CPUs and NUMA nodes in qom/cpu.c:
> cpu_common_realizefn(), where each VCPUs need to realize.
> 
> Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>

parse_numa_opts() is called a long time before any CPU is
created, so this should be safe.

Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

(But we can squash patch 2/3 and patch 3/3 in this patch).

> ---
>  qom/cpu.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/qom/cpu.c b/qom/cpu.c
> index 61ee0cb..e08dceb 100644
> --- a/qom/cpu.c
> +++ b/qom/cpu.c
> @@ -23,6 +23,7 @@
>  #include "qemu-common.h"
>  #include "qom/cpu.h"
>  #include "sysemu/kvm.h"
> +#include "sysemu/numa.h"
>  #include "qemu/notify.h"
>  #include "qemu/log.h"
>  #include "exec/log.h"
> @@ -338,6 +339,18 @@ static void cpu_common_parse_features(const char *typename, char *features,
>      }
>  }
>  
> +static void cpu_common_map_numa_node(CPUState *cpu)
> +{
> +    int i;
> +
> +    for (i = 0; i < nb_numa_nodes; i++) {
> +        assert(cpu->cpu_index < max_cpus);
> +        if (test_bit(cpu->cpu_index, numa_info[i].node_cpu)) {
> +            cpu->numa_node = i;
> +        }
> +    }
> +}
> +
>  static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>  {
>      CPUState *cpu = CPU(dev);
> @@ -347,6 +360,8 @@ static void cpu_common_realizefn(DeviceState *dev, Error **errp)
>          cpu_resume(cpu);
>      }
>  
> +    cpu_common_map_numa_node(cpu);
> +
>      /* NOTE: latest generic point where the cpu is fully realized */
>      trace_init_vcpu(cpu);
>  }
> -- 
> 2.5.5
> 
> 
> 

-- 
Eduardo