[PATCH v3 5/5] hw/loongarch/virt: Enable cpu hotplug feature on virt machine

[Bibo Mao]

On virt machine, enable CPU hotplug feature has_hotpluggable_cpus. For
hot-added CPUs after power on, interrupt pin of extioi and ipi interrupt
controller need connect to pins of new CPU.

Also change num-cpu property of extioi and ipi from smp.cpus to
smp.max_cpus

Co-developed-by: Xianglai Li <lixianglai@loongson.cn>
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
---
 hw/loongarch/virt.c         | 57 +++++++++++++++++++++++++++++++++----
 include/hw/loongarch/virt.h |  2 ++
 2 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index e73f689c83..6673493109 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -891,8 +891,9 @@ static void virt_irq_init(LoongArchVirtMachineState *lvms)
 
     /* Create IPI device */
     ipi = qdev_new(TYPE_LOONGARCH_IPI);
-    qdev_prop_set_uint32(ipi, "num-cpu", ms->smp.cpus);
+    qdev_prop_set_uint32(ipi, "num-cpu", ms->smp.max_cpus);
     sysbus_realize_and_unref(SYS_BUS_DEVICE(ipi), &error_fatal);
+    lvms->ipi = ipi;
 
     /* IPI iocsr memory region */
     memory_region_add_subregion(&lvms->system_iocsr, SMP_IPI_MAILBOX,
@@ -905,11 +906,12 @@ static void virt_irq_init(LoongArchVirtMachineState *lvms)
 
     /* Create EXTIOI device */
     extioi = qdev_new(TYPE_LOONGARCH_EXTIOI);
-    qdev_prop_set_uint32(extioi, "num-cpu", ms->smp.cpus);
+    qdev_prop_set_uint32(extioi, "num-cpu", ms->smp.max_cpus);
     if (virt_is_veiointc_enabled(lvms)) {
         qdev_prop_set_bit(extioi, "has-virtualization-extension", true);
     }
     sysbus_realize_and_unref(SYS_BUS_DEVICE(extioi), &error_fatal);
+    lvms->extioi = extioi;
     memory_region_add_subregion(&lvms->system_iocsr, APIC_BASE,
                     sysbus_mmio_get_region(SYS_BUS_DEVICE(extioi), 0));
     if (virt_is_veiointc_enabled(lvms)) {
@@ -1403,8 +1405,40 @@ static void virt_cpu_pre_plug(HotplugHandler 
*hotplug_dev,
      }
 
     if (cpu->phy_id == UNSET_PHY_ID) {
-        error_setg(&local_err, "CPU hotplug not supported");
-        goto out;
+        if ((cpu->thread_id < 0) || (cpu->thread_id >= ms->smp.threads)) {
+            error_setg(&local_err,
+                       "Invalid thread-id %u specified, must be in range 1:%u",
+                       cpu->thread_id, ms->smp.threads - 1);
+            goto out;
+        }
+
+        if ((cpu->core_id < 0) || (cpu->core_id >= ms->smp.cores)) {
+            error_setg(&local_err,
+                       "Invalid core-id %u specified, must be in range 1:%u",
+                       cpu->core_id, ms->smp.cores - 1);
+            goto out;
+        }
+
+        if ((cpu->socket_id < 0) || (cpu->socket_id >= ms->smp.sockets)) {
+            error_setg(&local_err,
+                       "Invalid socket-id %u specified, must be in range 1:%u",
+                       cpu->socket_id, ms->smp.sockets - 1);
+            goto out;
+        }
+
+        topo.socket_id = cpu->socket_id;
+        topo.core_id = cpu->core_id;
+        topo.thread_id = cpu->thread_id;
+        arch_id =  virt_get_arch_id_from_topo(ms, &topo);
+        cpu_slot = virt_find_cpu_slot(ms, arch_id, &index);
+        if (CPU(cpu_slot->cpu)) {
+            error_setg(&local_err,
+                       "cpu(id%d=%d:%d:%d) with arch-id %" PRIu64 " exists",
+                       cs->cpu_index, cpu->socket_id, cpu->core_id,
+                       cpu->thread_id, cpu_slot->arch_id);
+            goto out;
+        }
+        cpu->phy_id = arch_id;
     } else {
         /*
          * For cold-add cpu, topo property is not set. And only physical id
@@ -1484,10 +1518,22 @@ static void virt_cpu_plug(HotplugHandler *hotplug_dev,
                                 DeviceState *dev, Error **errp)
 {
     CPUArchId *cpu_slot;
+    Error *local_err = NULL;
     LoongArchCPU *cpu = LOONGARCH_CPU(dev);
+    MachineState *ms = MACHINE(hotplug_dev);
     LoongArchVirtMachineState *lvms = LOONGARCH_VIRT_MACHINE(hotplug_dev);
 
-    cpu_slot = virt_find_cpu_slot(MACHINE(lvms), cpu->phy_id, NULL);
+    if (lvms->acpi_ged) {
+        /* Connect irq to cpu, including ipi and extioi irqchip */
+        virt_init_cpu_irq(ms, CPU(cpu));
+        hotplug_handler_plug(HOTPLUG_HANDLER(lvms->acpi_ged), dev, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            return;
+        }
+    }
+
+    cpu_slot = virt_find_cpu_slot(ms, cpu->phy_id, NULL);
     cpu_slot->cpu = CPU(dev);
     return;
 }
@@ -1671,6 +1717,7 @@ static void virt_class_init(ObjectClass *oc, void *data)
     mc->numa_mem_supported = true;
     mc->auto_enable_numa_with_memhp = true;
     mc->auto_enable_numa_with_memdev = true;
+    mc->has_hotpluggable_cpus = true;
     mc->get_hotplug_handler = virt_get_hotplug_handler;
     mc->default_nic = "virtio-net-pci";
     hc->plug = virt_device_plug_cb;
diff --git a/include/hw/loongarch/virt.h b/include/hw/loongarch/virt.h
index 861034d614..79a85723c9 100644
--- a/include/hw/loongarch/virt.h
+++ b/include/hw/loongarch/virt.h
@@ -61,6 +61,8 @@ struct LoongArchVirtMachineState {
     MemoryRegion iocsr_mem;
     AddressSpace as_iocsr;
     struct loongarch_boot_info bootinfo;
+    DeviceState *ipi;
+    DeviceState *extioi;
 };
 
 #define TYPE_LOONGARCH_VIRT_MACHINE  MACHINE_TYPE_NAME("virt")
-- 
2.39.3