Re: [RFC PATCH 5/5] hw/arm/virt-acpi-build: add PPTT table

[Andrew Jones <drjones@redhat.com>]

This is just [*] with some minor code changes

[*] https://github.com/rhdrjones/qemu/commit/439b38d67ca1f2cbfa5b9892a822b651ebd05c11

so it's disappointing that my name is nowhere to be found on it.

Also, the explanation of the DT and ACPI differences has been
dropped from the commit message of [*]. I'm not sure why.

Thanks,
drew

On Thu, Feb 25, 2021 at 04:56:27PM +0800, Ying Fang wrote:
> Add the Processor Properties Topology Table (PPTT) to present
> CPU topology information to the guest. A three-level cpu
> topology is built in accord with the linux kernel currently does.
> 
> Tested-by: Jiajie Li <lijiajie11@huawei.com>
> Signed-off-by: Ying Fang <fangying1@huawei.com>
> ---
>  hw/arm/virt-acpi-build.c | 50 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index bb91152fe2..38d50ce66c 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -436,6 +436,50 @@ build_srat(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>                   vms->oem_table_id);
>  }
>  
> +static void
> +build_pptt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> +{
> +    int pptt_start = table_data->len;
> +    int uid = 0, cpus = 0, socket = 0;
> +    MachineState *ms = MACHINE(vms);
> +    unsigned int smp_cores = ms->smp.cores;
> +    unsigned int smp_threads = ms->smp.threads;
> +
> +    acpi_data_push(table_data, sizeof(AcpiTableHeader));
> +
> +    for (socket = 0; cpus < ms->possible_cpus->len; socket++) {
> +        uint32_t socket_offset = table_data->len - pptt_start;
> +        int core;
> +
> +        build_socket_hierarchy(table_data, 0, socket);
> +
> +        for (core = 0; core < smp_cores; core++) {
> +            uint32_t core_offset = table_data->len - pptt_start;
> +            int thread;
> +
> +            if (smp_threads <= 1) {
> +                build_processor_hierarchy(table_data,
> +                                          ACPI_PPTT_ACPI_PROCESSOR_ID_VALID |
> +                                          ACPI_PPTT_ACPI_LEAF_NODE,
> +                                          socket_offset, uid++);
> +             } else {
> +                build_processor_hierarchy(table_data,
> +                                          ACPI_PPTT_ACPI_PROCESSOR_ID_VALID,
> +                                          socket_offset, core);
> +                for (thread = 0; thread < smp_threads; thread++) {
> +                    build_thread_hierarchy(table_data, core_offset, uid++);
> +                }
> +             }
> +        }
> +        cpus += smp_cores * smp_threads;
> +    }
> +
> +    build_header(linker, table_data,
> +                 (void *)(table_data->data + pptt_start), "PPTT",
> +                 table_data->len - pptt_start, 2,
> +                 vms->oem_id, vms->oem_table_id);
> +}
> +
>  /* GTDT */
>  static void
>  build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> @@ -688,6 +732,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>      unsigned dsdt, xsdt;
>      GArray *tables_blob = tables->table_data;
>      MachineState *ms = MACHINE(vms);
> +    bool cpu_topology_enabled = !vmc->no_cpu_topology;
>  
>      table_offsets = g_array_new(false, true /* clear */,
>                                          sizeof(uint32_t));
> @@ -707,6 +752,11 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>      acpi_add_table(table_offsets, tables_blob);
>      build_madt(tables_blob, tables->linker, vms);
>  
> +    if (ms->smp.cpus > 1 && cpu_topology_enabled) {
> +        acpi_add_table(table_offsets, tables_blob);
> +        build_pptt(tables_blob, tables->linker, vms);
> +    }
> +
>      acpi_add_table(table_offsets, tables_blob);
>      build_gtdt(tables_blob, tables->linker, vms);
>  
> -- 
> 2.23.0
> 
>