On Wed, Apr 23, 2025 at 12:41:28PM +0100, Alireza Sanaee wrote:
> From: Yicong Yang <yangyic...@hisilicon.com>
>
> Currently we build the PPTT starting from the socket node and each
> socket will be a separate tree. For a multi-socket system it'll
> be hard for the OS to know the whole system is homogeneous or not
> (actually we're in the current implementation) since no parent node
> to telling the identical implementation informentation. Add a
> root node for indicating this.
>
> Signed-off-by: Yicong Yang <yangyic...@hisilicon.com>
> Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com>
> Signed-off-by: Alireza Sanaee <alireza.san...@huawei.com>
so how does the topology look before and after this change?
> ---
> hw/acpi/aml-build.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 560cee12a24b..3010325ca423 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -2153,12 +2153,25 @@ void build_pptt(GArray *table_data, BIOSLinker
> *linker, MachineState *ms,
> int64_t socket_id = -1, cluster_id = -1, core_id = -1;
> uint32_t socket_offset = 0, cluster_offset = 0, core_offset = 0;
> uint32_t pptt_start = table_data->len;
> + uint32_t root_offset;
> int n;
> AcpiTable table = { .sig = "PPTT", .rev = 2,
> .oem_id = oem_id, .oem_table_id = oem_table_id };
>
> acpi_table_begin(&table, table_data);
>
> + /*
> + * Build a root node for all the processor nodes. Otherwise when
> + * building a multi-socket system each socket tree are separated
is separated?
> + * and will be hard for the OS like Linux to know whether the
> + * system is homogeneous.
> + */
> + root_offset = table_data->len - pptt_start;
> + build_processor_hierarchy_node(table_data,
> + (1 << 0) | /* Physical package */
> + (1 << 4), /* Identical Implementation */
> + 0, 0, NULL, 0);
> +
> /*
> * This works with the assumption that cpus[n].props.*_id has been
> * sorted from top to down levels in mc->possible_cpu_arch_ids().
> @@ -2175,7 +2188,7 @@ void build_pptt(GArray *table_data, BIOSLinker *linker,
> MachineState *ms,
> build_processor_hierarchy_node(table_data,
> (1 << 0) | /* Physical package */
> (1 << 4), /* Identical Implementation */
> - 0, socket_id, NULL, 0);
> + root_offset, socket_id, NULL, 0);
> }
>
> if (mc->smp_props.clusters_supported && mc->smp_props.has_clusters) {
> --
> 2.34.1
