Re: [PATCH v6 2/4] hw/arm/virt: Consider SMP configuration in CPU topology

[Igor Mammedov]

On Mon, 18 Apr 2022 10:09:18 +0800
Gavin Shan <gshan@redhat.com> wrote:

> Currently, the SMP configuration isn't considered when the CPU
> topology is populated. In this case, it's impossible to provide
> the default CPU-to-NUMA mapping or association based on the socket
> ID of the given CPU.
> 
> This takes account of SMP configuration when the CPU topology
> is populated. The die ID for the given CPU isn't assigned since
> it's not supported on arm/virt machine. Besides, the used SMP
> configuration in qtest/numa-test/aarch64_numa_cpu() is corrcted
> to avoid testing failure
> 
> Signed-off-by: Gavin Shan <gshan@redhat.com>
> Reviewed-by: Yanan Wang <wangyanan55@huawei.com>
> ---
>  hw/arm/virt.c           | 15 ++++++++++++++-
>  tests/qtest/numa-test.c |  3 ++-
>  2 files changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index d2e5ecd234..5443ecae92 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -2505,6 +2505,7 @@ static const CPUArchIdList 
> *virt_possible_cpu_arch_ids(MachineState *ms)
>      int n;
>      unsigned int max_cpus = ms->smp.max_cpus;
>      VirtMachineState *vms = VIRT_MACHINE(ms);
> +    MachineClass *mc = MACHINE_GET_CLASS(vms);
>  
>      if (ms->possible_cpus) {
>          assert(ms->possible_cpus->len == max_cpus);
> @@ -2518,8 +2519,20 @@ static const CPUArchIdList 
> *virt_possible_cpu_arch_ids(MachineState *ms)
>          ms->possible_cpus->cpus[n].type = ms->cpu_type;
>          ms->possible_cpus->cpus[n].arch_id =
>              virt_cpu_mp_affinity(vms, n);
> +
> +        assert(!mc->smp_props.dies_supported);
> +        ms->possible_cpus->cpus[n].props.has_socket_id = true;
> +        ms->possible_cpus->cpus[n].props.socket_id =
> +            (n / (ms->smp.clusters * ms->smp.cores * ms->smp.threads));
> +        ms->possible_cpus->cpus[n].props.has_cluster_id = true;
> +        ms->possible_cpus->cpus[n].props.cluster_id =
> +            (n / (ms->smp.cores * ms->smp.threads)) % ms->smp.clusters;
> +        ms->possible_cpus->cpus[n].props.has_core_id = true;
> +        ms->possible_cpus->cpus[n].props.core_id =
> +            (n / ms->smp.threads) % ms->smp.cores;
>          ms->possible_cpus->cpus[n].props.has_thread_id = true;
> -        ms->possible_cpus->cpus[n].props.thread_id = n;
> +        ms->possible_cpus->cpus[n].props.thread_id =
> +            n % ms->smp.threads;
>      }
>      return ms->possible_cpus;
>  }
> diff --git a/tests/qtest/numa-test.c b/tests/qtest/numa-test.c
> index 90bf68a5b3..aeda8c774c 100644
> --- a/tests/qtest/numa-test.c
> +++ b/tests/qtest/numa-test.c
> @@ -223,7 +223,8 @@ static void aarch64_numa_cpu(const void *data)
>      QTestState *qts;
>      g_autofree char *cli = NULL;
>  
> -    cli = make_cli(data, "-machine smp.cpus=2 "
> +    cli = make_cli(data, "-machine "
> +        "smp.cpus=2,smp.sockets=1,smp.clusters=1,smp.cores=1,smp.threads=2 "

Is cluster-less config possible?
(looks like it used to work before and it doesn't after this series)

>          "-numa node,nodeid=0,memdev=ram -numa node,nodeid=1 "
>          "-numa cpu,node-id=1,thread-id=0 "
>          "-numa cpu,node-id=0,thread-id=1");