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

[Ying Fang]

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