[PATCH v8 21/29] hw/isa/piix: Allow for optional PIT creation in PIIX3

[Bernhard Beschow <shentey@gmail.com>]

In the PC machine, the PIT is created in board code to allow it to be
virtualized with various virtualization techniques. So explicitly disable its
creation in the PC machine via a property which defaults to enabled. Once the
PIIX implementations are consolidated this default will keep Malta working
without further ado.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
---
 include/hw/southbridge/piix.h | 1 +
 hw/i386/pc_piix.c             | 2 ++
 hw/isa/piix.c                 | 6 ++++++
 3 files changed, 9 insertions(+)

diff --git a/include/hw/southbridge/piix.h b/include/hw/southbridge/piix.h
index 08491693b4..86709ba2e4 100644
--- a/include/hw/southbridge/piix.h
+++ b/include/hw/southbridge/piix.h
@@ -70,6 +70,7 @@ struct PIIXState {
 
     bool has_acpi;
     bool has_pic;
+    bool has_pit;
     bool has_usb;
     bool smm_enabled;
 };
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index fa39afd891..e38942a3c3 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -270,6 +270,8 @@ static void pc_init1(MachineState *machine,
                                  &error_abort);
         object_property_set_bool(OBJECT(pci_dev), "has-pic", false,
                                  &error_abort);
+        object_property_set_bool(OBJECT(pci_dev), "has-pit", false,
+                                 &error_abort);
         qdev_prop_set_uint32(DEVICE(pci_dev), "smb_io_base", 0xb100);
         object_property_set_bool(OBJECT(pci_dev), "smm-enabled",
                                  x86_machine_is_smm_enabled(x86ms),
diff --git a/hw/isa/piix.c b/hw/isa/piix.c
index d6d9ac6473..270b8eb1f7 100644
--- a/hw/isa/piix.c
+++ b/hw/isa/piix.c
@@ -361,6 +361,11 @@ static void pci_piix3_realize(PCIDevice *dev, Error **errp)
 
     isa_bus_register_input_irqs(isa_bus, d->isa_irqs_in);
 
+    /* PIT */
+    if (d->has_pit) {
+        i8254_pit_init(isa_bus, 0x40, 0, NULL);
+    }
+
     i8257_dma_init(isa_bus, 0);
 
     /* RTC */
@@ -436,6 +441,7 @@ static Property pci_piix3_props[] = {
     DEFINE_PROP_UINT32("smb_io_base", PIIXState, smb_io_base, 0),
     DEFINE_PROP_BOOL("has-acpi", PIIXState, has_acpi, true),
     DEFINE_PROP_BOOL("has-pic", PIIXState, has_pic, true),
+    DEFINE_PROP_BOOL("has-pit", PIIXState, has_pit, true),
     DEFINE_PROP_BOOL("has-usb", PIIXState, has_usb, true),
     DEFINE_PROP_BOOL("smm-enabled", PIIXState, smm_enabled, false),
     DEFINE_PROP_END_OF_LIST(),
-- 
2.42.0