hw/loongarch/virt: Update the ACPI table for hotplug cpu

On LoongArch virt machine, ACPI GED hardware is used for CPU hotplug
handler, here CPU hotplug support feature is added based on GED handler,
also CPU scan and reject method is added about CPU device in DSDT table.

Co-developed-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>

hw/loongarch/Kconfig

@@ -17,6 +17,7 @@ config LOONGARCH_VIRT
     select LOONGARCH_EXTIOI
     select LS7A_RTC
     select SMBIOS
+    select ACPI_CPU_HOTPLUG
     select ACPI_PCI
     select ACPI_HW_REDUCED
     select FW_CFG_DMA

hw/loongarch/virt-acpi-build.c

@@ -47,6 +47,22 @@
 #define ACPI_BUILD_DPRINTF(fmt, ...)
 #endif
 
+static void virt_madt_cpu_entry(int uid,
+                                const CPUArchIdList *apic_ids,
+                                GArray *entry, bool force_enabled)
+{
+    uint32_t flags, apic_id = apic_ids->cpus[uid].arch_id;
+
+    flags = apic_ids->cpus[uid].cpu || force_enabled ? 1 /* Enabled */ : 0;
+
+    /* Rev 1.0b, Table 5-13 Processor Local APIC Structure */
+    build_append_int_noprefix(entry, 0, 1);       /* Type */
+    build_append_int_noprefix(entry, 8, 1);       /* Length */
+    build_append_int_noprefix(entry, uid, 1);     /* ACPI Processor ID */
+    build_append_int_noprefix(entry, apic_id, 1); /* APIC ID */
+    build_append_int_noprefix(entry, flags, 4); /* Flags */
+}
+
 /* build FADT */
 static void init_common_fadt_data(AcpiFadtData *data)
 {
@@ -112,7 +128,7 @@ build_madt(GArray *table_data, BIOSLinker *linker,
     MachineState *ms = MACHINE(lvms);
     MachineClass *mc = MACHINE_GET_CLASS(ms);
     const CPUArchIdList *arch_ids = mc->possible_cpu_arch_ids(ms);
-    int i, arch_id;
+    int i, arch_id, flags;
     AcpiTable table = { .sig = "APIC", .rev = 1, .oem_id = lvms->oem_id,
                         .oem_table_id = lvms->oem_table_id };
 
@@ -125,13 +141,13 @@ build_madt(GArray *table_data, BIOSLinker *linker,
     for (i = 0; i < arch_ids->len; i++) {
         /* Processor Core Interrupt Controller Structure */
         arch_id = arch_ids->cpus[i].arch_id;
-
+        flags   = arch_ids->cpus[i].cpu ? 1 : 0;
         build_append_int_noprefix(table_data, 17, 1);    /* Type */
         build_append_int_noprefix(table_data, 15, 1);    /* Length */
         build_append_int_noprefix(table_data, 1, 1);     /* Version */
         build_append_int_noprefix(table_data, i, 4);     /* ACPI Processor ID */
         build_append_int_noprefix(table_data, arch_id, 4); /* Core ID */
-        build_append_int_noprefix(table_data, 1, 4);     /* Flags */
+        build_append_int_noprefix(table_data, flags, 4); /* Flags */
     }
 
     /* Extend I/O Interrupt Controller Structure */
@@ -338,6 +354,7 @@ build_la_ged_aml(Aml *dsdt, MachineState *machine)
 {
     uint32_t event;
     LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(machine);
+    CPUHotplugFeatures opts;
 
     build_ged_aml(dsdt, "\\_SB."GED_DEVICE,
                   HOTPLUG_HANDLER(lvms->acpi_ged),
@@ -350,6 +367,18 @@ build_la_ged_aml(Aml *dsdt, MachineState *machine)
                                  AML_SYSTEM_MEMORY,
                                  VIRT_GED_MEM_ADDR);
     }
+
+    if (event & ACPI_GED_CPU_HOTPLUG_EVT) {
+        opts.acpi_1_compatible = false;
+        opts.has_legacy_cphp = false;
+        opts.fw_unplugs_cpu = false;
+        opts.smi_path = NULL;
+
+        build_cpus_aml(dsdt, machine, opts, virt_madt_cpu_entry,
+                       VIRT_GED_CPUHP_ADDR, "\\_SB",
+                       AML_GED_EVT_CPU_SCAN_METHOD, AML_SYSTEM_MEMORY);
+    }
+
     acpi_dsdt_add_power_button(dsdt);
 }
 

hw/loongarch/virt.c

@@ -187,11 +187,17 @@ static DeviceState *create_acpi_ged(DeviceState *pch_pic,
 {
     DeviceState *dev;
     MachineState *ms = MACHINE(lvms);
+    MachineClass *mc = MACHINE_GET_CLASS(lvms);
     uint32_t event = ACPI_GED_PWR_DOWN_EVT;
 
     if (ms->ram_slots) {
         event |= ACPI_GED_MEM_HOTPLUG_EVT;
     }
+
+    if (mc->has_hotpluggable_cpus) {
+        event |= ACPI_GED_CPU_HOTPLUG_EVT;
+    }
+
     dev = qdev_new(TYPE_ACPI_GED);
     qdev_prop_set_uint32(dev, "ged-event", event);
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
@@ -203,6 +209,10 @@ static DeviceState *create_acpi_ged(DeviceState *pch_pic,
     /* ged regs used for reset and power down */
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 2, VIRT_GED_REG_ADDR);
 
+    if (mc->has_hotpluggable_cpus) {
+        sysbus_mmio_map(SYS_BUS_DEVICE(dev), 3, VIRT_GED_CPUHP_ADDR);
+    }
+
     sysbus_connect_irq(SYS_BUS_DEVICE(dev), 0,
                        qdev_get_gpio_in(pch_pic, VIRT_SCI_IRQ - VIRT_GSI_BASE));
     return dev;

include/hw/loongarch/virt.h

@@ -30,6 +30,7 @@
 #define VIRT_GED_EVT_ADDR       0x100e0000
 #define VIRT_GED_MEM_ADDR       (VIRT_GED_EVT_ADDR + ACPI_GED_EVT_SEL_LEN)
 #define VIRT_GED_REG_ADDR       (VIRT_GED_MEM_ADDR + MEMORY_HOTPLUG_IO_LEN)
+#define VIRT_GED_CPUHP_ADDR     (VIRT_GED_REG_ADDR + ACPI_GED_REG_COUNT)
 
 #define COMMAND_LINE_SIZE       512