Re: [Qemu-devel] [PATCH v3 1/9] i386: Add die-level cpu topology to x86CPU on PCMachine

[Eduardo Habkost]

On Wed, Jun 12, 2019 at 04:40:56PM +0800, Like Xu wrote:
> The die-level as the first PC-specific cpu topology is added to the leagcy
> cpu topology model, which has one die per package implicitly and only the
> numbers of sockets/cores/threads are configurable.
> 
> In the new model with die-level support, the total number of logical
> processors (including offline) on board will be calculated as:
> 
>      #cpus = #sockets * #dies * #cores * #threads
> 
> and considering compatibility, the default value for #dies would be
> initialized to one in x86_cpu_initfn() and pc_machine_initfn().
> 
> Signed-off-by: Like Xu <address@hidden>

Reviewed-by: Eduardo Habkost <address@hidden>

> ---
>  hw/i386/pc.c         | 9 +++++++--
>  include/hw/i386/pc.h | 2 ++
>  target/i386/cpu.c    | 1 +
>  target/i386/cpu.h    | 2 ++
>  4 files changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 12c1e08b85..9e9a42f007 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2308,9 +2308,13 @@ static void pc_cpu_pre_plug(HotplugHandler 
> *hotplug_dev,
>          return;
>      }
>  
> -    /* if APIC ID is not set, set it based on socket/core/thread properties 
> */
> +    /*
> +     * If APIC ID is not set,
> +     * set it based on socket/die/core/thread properties.
> +     */
>      if (cpu->apic_id == UNASSIGNED_APIC_ID) {
> -        int max_socket = (ms->smp.max_cpus - 1) / smp_threads / smp_cores;
> +        int max_socket = (ms->smp.max_cpus - 1) /
> +                                smp_threads / smp_cores / pcms->smp_dies;
>  
>          if (cpu->socket_id < 0) {
>              error_setg(errp, "CPU socket-id is not set");
> @@ -2620,6 +2624,7 @@ static void pc_machine_initfn(Object *obj)
>      pcms->smbus_enabled = true;
>      pcms->sata_enabled = true;
>      pcms->pit_enabled = true;
> +    pcms->smp_dies = 1;
>  
>      pc_system_flash_create(pcms);
>  }
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index b260262640..fae9217e34 100644
> --- a/include/hw/i386/pc.h
> +++ b/include/hw/i386/pc.h
> @@ -24,6 +24,7 @@
>   * PCMachineState:
>   * @acpi_dev: link to ACPI PM device that performs ACPI hotplug handling
>   * @boot_cpus: number of present VCPUs
> + * @smp_dies: number of dies per one package
>   */
>  struct PCMachineState {
>      /*< private >*/
> @@ -59,6 +60,7 @@ struct PCMachineState {
>      bool apic_xrupt_override;
>      unsigned apic_id_limit;
>      uint16_t boot_cpus;
> +    unsigned smp_dies;
>  
>      /* NUMA information: */
>      uint64_t numa_nodes;
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 23119699de..a16be205fe 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5619,6 +5619,7 @@ static void x86_cpu_initfn(Object *obj)
>      CPUX86State *env = &cpu->env;
>      FeatureWord w;
>  
> +    env->nr_dies = 1;
>      cpu_set_cpustate_pointers(cpu);
>  
>      object_property_add(obj, "family", "int",
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index edad6e1efb..5daa2eeafa 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1349,6 +1349,8 @@ typedef struct CPUX86State {
>      uint64_t xss;
>  
>      TPRAccess tpr_access_type;
> +
> +    unsigned nr_dies;
>  } CPUX86State;
>  
>  struct kvm_msrs;
> -- 
> 2.21.0
> 

-- 
Eduardo