hw/i386/pc: Create RTC controllers in south bridges

Just like in the real hardware (and in PIIX4), create the RTC
controllers in the south bridges.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20230519084734.220480-2-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/i386/pc.c

@@ -1318,7 +1318,17 @@ void pc_basic_device_init(struct PCMachineState *pcms,
         pit_alt_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_PIT_INT);
         rtc_irq = qdev_get_gpio_in(hpet, HPET_LEGACY_RTC_INT);
     }
-    *rtc_state = ISA_DEVICE(mc146818_rtc_init(isa_bus, 2000, rtc_irq));
+
+    if (rtc_irq) {
+        qdev_connect_gpio_out(DEVICE(*rtc_state), 0, rtc_irq);
+    } else {
+        uint32_t irq = object_property_get_uint(OBJECT(*rtc_state),
+                                                "irq",
+                                                &error_fatal);
+        isa_connect_gpio_out(*rtc_state, 0, irq);
+    }
+    object_property_add_alias(OBJECT(pcms), "rtc-time", OBJECT(*rtc_state),
+                              "date");
 
 #ifdef CONFIG_XEN_EMU
     if (xen_mode == XEN_EMULATE) {

hw/i386/pc_piix.c

@@ -32,6 +32,7 @@
 #include "hw/i386/pc.h"
 #include "hw/i386/apic.h"
 #include "hw/pci-host/i440fx.h"
+#include "hw/rtc/mc146818rtc.h"
 #include "hw/southbridge/piix.h"
 #include "hw/display/ramfb.h"
 #include "hw/firmware/smbios.h"
@@ -240,10 +241,17 @@ static void pc_init1(MachineState *machine,
         piix3->pic = x86ms->gsi;
         piix3_devfn = piix3->dev.devfn;
         isa_bus = ISA_BUS(qdev_get_child_bus(DEVICE(piix3), "isa.0"));
+        rtc_state = ISA_DEVICE(object_resolve_path_component(OBJECT(pci_dev),
+                                                             "rtc"));
     } else {
         pci_bus = NULL;
         isa_bus = isa_bus_new(NULL, system_memory, system_io,
                               &error_abort);
+
+        rtc_state = isa_new(TYPE_MC146818_RTC);
+        qdev_prop_set_int32(DEVICE(rtc_state), "base_year", 2000);
+        isa_realize_and_unref(rtc_state, isa_bus, &error_fatal);
+
         i8257_dma_init(isa_bus, 0);
         pcms->hpet_enabled = false;
     }

hw/i386/pc_q35.c

@@ -241,6 +241,8 @@ static void pc_q35_init(MachineState *machine)
                       x86_machine_is_smm_enabled(x86ms));
     pci_realize_and_unref(lpc, host_bus, &error_fatal);
 
+    rtc_state = ISA_DEVICE(object_resolve_path_component(OBJECT(lpc), "rtc"));
+
     object_property_add_link(OBJECT(machine), PC_MACHINE_ACPI_DEVICE_PROP,
                              TYPE_HOTPLUG_HANDLER,
                              (Object **)&x86ms->acpi_dev,

hw/isa/Kconfig

@@ -35,6 +35,7 @@ config PIIX3
     bool
     select I8257
     select ISA_BUS
+    select MC146818RTC
 
 config PIIX4
     bool
@@ -79,3 +80,4 @@ config LPC_ICH9
     select I8257
     select ISA_BUS
     select ACPI_ICH9
+    select MC146818RTC

hw/isa/lpc_ich9.c

@@ -658,6 +658,8 @@ static void ich9_lpc_initfn(Object *obj)
     static const uint8_t acpi_enable_cmd = ICH9_APM_ACPI_ENABLE;
     static const uint8_t acpi_disable_cmd = ICH9_APM_ACPI_DISABLE;
 
+    object_initialize_child(obj, "rtc", &lpc->rtc, TYPE_MC146818_RTC);
+
     object_property_add_uint8_ptr(obj, ACPI_PM_PROP_SCI_INT,
                                   &lpc->sci_gsi, OBJ_PROP_FLAG_READ);
     object_property_add_uint8_ptr(OBJECT(lpc), ACPI_PM_PROP_ACPI_ENABLE_CMD,
@@ -723,6 +725,12 @@ static void ich9_lpc_realize(PCIDevice *d, Error **errp)
 
     i8257_dma_init(isa_bus, 0);
 
+    /* RTC */
+    qdev_prop_set_int32(DEVICE(&lpc->rtc), "base_year", 2000);
+    if (!qdev_realize(DEVICE(&lpc->rtc), BUS(isa_bus), errp)) {
+        return;
+    }
+
     pci_bus_irqs(pci_bus, ich9_lpc_set_irq, d, ICH9_LPC_NB_PIRQS);
     pci_bus_map_irqs(pci_bus, ich9_lpc_map_irq);
     pci_bus_set_route_irq_fn(pci_bus, ich9_route_intx_pin_to_irq);

hw/isa/piix3.c

@@ -28,6 +28,7 @@
 #include "hw/dma/i8257.h"
 #include "hw/southbridge/piix.h"
 #include "hw/irq.h"
+#include "hw/qdev-properties.h"
 #include "hw/isa/isa.h"
 #include "hw/xen/xen.h"
 #include "sysemu/runstate.h"
@@ -301,6 +302,12 @@ static void pci_piix3_realize(PCIDevice *dev, Error **errp)
                                         PIIX_RCR_IOPORT, &d->rcr_mem, 1);
 
     i8257_dma_init(isa_bus, 0);
+
+    /* RTC */
+    qdev_prop_set_int32(DEVICE(&d->rtc), "base_year", 2000);
+    if (!qdev_realize(DEVICE(&d->rtc), BUS(isa_bus), errp)) {
+        return;
+    }
 }
 
 static void build_pci_isa_aml(AcpiDevAmlIf *adev, Aml *scope)
@@ -324,6 +331,13 @@ static void build_pci_isa_aml(AcpiDevAmlIf *adev, Aml *scope)
     qbus_build_aml(bus, scope);
 }
 
+static void pci_piix3_init(Object *obj)
+{
+    PIIX3State *d = PIIX3_PCI_DEVICE(obj);
+
+    object_initialize_child(obj, "rtc", &d->rtc, TYPE_MC146818_RTC);
+}
+
 static void pci_piix3_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -350,6 +364,7 @@ static const TypeInfo piix3_pci_type_info = {
     .name = TYPE_PIIX3_PCI_DEVICE,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PIIX3State),
+    .instance_init = pci_piix3_init,
     .abstract = true,
     .class_init = pci_piix3_class_init,
     .interfaces = (InterfaceInfo[]) {

include/hw/southbridge/ich9.h

@@ -6,6 +6,7 @@
 #include "hw/intc/ioapic.h"
 #include "hw/pci/pci.h"
 #include "hw/pci/pci_device.h"
+#include "hw/rtc/mc146818rtc.h"
 #include "exec/memory.h"
 #include "qemu/notify.h"
 #include "qom/object.h"
@@ -30,6 +31,7 @@ struct ICH9LPCState {
     */
     uint8_t irr[PCI_SLOT_MAX][PCI_NUM_PINS];
 
+    MC146818RtcState rtc;
     APMState apm;
     ICH9LPCPMRegs pm;
     uint32_t sci_level; /* track sci level */

include/hw/southbridge/piix.h

@@ -13,6 +13,7 @@
 #define HW_SOUTHBRIDGE_PIIX_H
 
 #include "hw/pci/pci_device.h"
+#include "hw/rtc/mc146818rtc.h"
 
 /* PIRQRC[A:D]: PIRQx Route Control Registers */
 #define PIIX_PIRQCA 0x60
@@ -51,6 +52,8 @@ struct PIIXState {
     /* This member isn't used. Just for save/load compatibility */
     int32_t pci_irq_levels_vmstate[PIIX_NUM_PIRQS];
 
+    MC146818RtcState rtc;
+
     /* Reset Control Register contents */
     uint8_t rcr;