Re: [Qemu-devel] [PATCH v2 1/5] target/i386: Add cpu die-level topology support for X86CPU

[Eduardo Habkost]

On Tue, May 21, 2019 at 12:50:52AM +0800, Like Xu wrote:
> The die-level as the first PC-specific cpu topology is added to the
> leagcy cpu topology model which only covers sockets/cores/threads.
> 
> 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 is 1.
> 
> A new set of die-related variables are added in smp context and the
> CPUX86State.nr_dies is assigned in x86_cpu_initfn() from PCMachineState.
> 
> Signed-off-by: Like Xu <address@hidden>
> ---
>  hw/i386/pc.c               | 3 +++
>  include/hw/i386/pc.h       | 2 ++
>  include/hw/i386/topology.h | 2 ++
>  qapi/misc.json             | 6 ++++--
>  target/i386/cpu.c          | 9 +++++++++
>  target/i386/cpu.h          | 3 +++
>  6 files changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index 896c22e32e..83ab53c814 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2341,6 +2341,7 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev,
>  
>          topo.pkg_id = cpu->socket_id;
>          topo.core_id = cpu->core_id;
> +        topo.die_id = cpu->die_id;
>          topo.smt_id = cpu->thread_id;
>          cpu->apic_id = apicid_from_topo_ids(smp_cores, smp_threads, &topo);
>      }
> @@ -2692,6 +2693,8 @@ static const CPUArchIdList 
> *pc_possible_cpu_arch_ids(MachineState *ms)
>                                   ms->smp.cores, ms->smp.threads, &topo);
>          ms->possible_cpus->cpus[i].props.has_socket_id = true;
>          ms->possible_cpus->cpus[i].props.socket_id = topo.pkg_id;
> +        ms->possible_cpus->cpus[i].props.has_die_id = true;
> +        ms->possible_cpus->cpus[i].props.die_id = topo.die_id;
>          ms->possible_cpus->cpus[i].props.has_core_id = true;
>          ms->possible_cpus->cpus[i].props.core_id = topo.core_id;
>          ms->possible_cpus->cpus[i].props.has_thread_id = true;
> diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
> index ce3c22951e..b5faf2ede9 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/include/hw/i386/topology.h b/include/hw/i386/topology.h
> index 1ebaee0f76..7f80498eb3 100644
> --- a/include/hw/i386/topology.h
> +++ b/include/hw/i386/topology.h
> @@ -47,6 +47,7 @@ typedef uint32_t apic_id_t;
>  
>  typedef struct X86CPUTopoInfo {
>      unsigned pkg_id;
> +    unsigned die_id;

Isn't it better to add this field only on patch 4/5?

>      unsigned core_id;
>      unsigned smt_id;
>  } X86CPUTopoInfo;
> @@ -130,6 +131,7 @@ static inline void x86_topo_ids_from_apicid(apic_id_t 
> apicid,
>      topo->core_id = (apicid >> apicid_core_offset(nr_cores, nr_threads)) &
>                     ~(0xFFFFFFFFUL << apicid_core_width(nr_cores, 
> nr_threads));
>      topo->pkg_id = apicid >> apicid_pkg_offset(nr_cores, nr_threads);
> +    topo->die_id = -1;

Why are you setting die_id = -1 here?

If die_id isn't valid yet, isn't it better to keep has_die_id =
false at pc_possible_cpu_arch_ids() above, and set has_die_id =
true only on patch 4/5?

>  }
>  
>  /* Make APIC ID for the CPU 'cpu_index'
> diff --git a/qapi/misc.json b/qapi/misc.json
> index 8b3ca4fdd3..cd236c89b3 100644
> --- a/qapi/misc.json
> +++ b/qapi/misc.json
> @@ -2924,10 +2924,11 @@
>  #
>  # @node-id: NUMA node ID the CPU belongs to
>  # @socket-id: socket number within node/board the CPU belongs to
> -# @core-id: core number within socket the CPU belongs to
> +# @die-id: die number within node/board the CPU belongs to (Since 4.1)
> +# @core-id: core number within die the CPU belongs to
>  # @thread-id: thread number within core the CPU belongs to
>  #
> -# Note: currently there are 4 properties that could be present
> +# Note: currently there are 5 properties that could be present
>  # but management should be prepared to pass through other
>  # properties with device_add command to allow for future
>  # interface extension. This also requires the filed names to be kept in
> @@ -2938,6 +2939,7 @@
>  { 'struct': 'CpuInstanceProperties',
>    'data': { '*node-id': 'int',
>              '*socket-id': 'int',
> +            '*die-id': 'int',
>              '*core-id': 'int',
>              '*thread-id': 'int'
>    }
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 9a93dd8be7..9bd35b4965 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -55,6 +55,7 @@
>  #include "hw/xen/xen.h"
>  #include "hw/i386/apic_internal.h"
>  #include "hw/boards.h"
> +#include "hw/i386/pc.h"
>  #endif
>  
>  #include "disas/capstone.h"
> @@ -5595,7 +5596,13 @@ static void x86_cpu_initfn(Object *obj)
>      X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
>      CPUX86State *env = &cpu->env;
>      FeatureWord w;
> +#ifndef CONFIG_USER_ONLY
> +    MachineState *machine = MACHINE(qdev_get_machine());
> +    PCMachineState *pcms = (PCMachineState *)
> +        object_dynamic_cast(OBJECT(machine), TYPE_PC_MACHINE);
>  
> +    env->nr_dies = pcms ? pcms->smp_dies : 1;
> +#endif
>      cs->env_ptr = env;
>  
>      object_property_add(obj, "family", "int",
> @@ -5812,11 +5819,13 @@ static Property x86_cpu_properties[] = {
>      DEFINE_PROP_UINT32("apic-id", X86CPU, apic_id, 0),
>      DEFINE_PROP_INT32("thread-id", X86CPU, thread_id, 0),
>      DEFINE_PROP_INT32("core-id", X86CPU, core_id, 0),
> +    DEFINE_PROP_INT32("die-id", X86CPU, die_id, 0),
>      DEFINE_PROP_INT32("socket-id", X86CPU, socket_id, 0),
>  #else
>      DEFINE_PROP_UINT32("apic-id", X86CPU, apic_id, UNASSIGNED_APIC_ID),
>      DEFINE_PROP_INT32("thread-id", X86CPU, thread_id, -1),
>      DEFINE_PROP_INT32("core-id", X86CPU, core_id, -1),
> +    DEFINE_PROP_INT32("die-id", X86CPU, die_id, -1),
>      DEFINE_PROP_INT32("socket-id", X86CPU, socket_id, -1),
>  #endif
>      DEFINE_PROP_INT32("node-id", X86CPU, node_id, CPU_UNSET_NUMA_NODE_ID),
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index fce6660bac..d5f2a60ff5 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1361,6 +1361,8 @@ typedef struct CPUX86State {
>      uint64_t xss;
>  
>      TPRAccess tpr_access_type;
> +
> +    unsigned nr_dies;
>  } CPUX86State;
>  
>  struct kvm_msrs;
> @@ -1484,6 +1486,7 @@ struct X86CPU {
>  
>      int32_t node_id; /* NUMA node this CPU belongs to */
>      int32_t socket_id;
> +    int32_t die_id;
>      int32_t core_id;
>      int32_t thread_id;
>  
> -- 
> 2.21.0
> 
> 

-- 
Eduardo