hw/isa/piix: Allow for optional PIT creation in PIIX3

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> Message-Id: <20231007123843.127151-22-shentey@gmail.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
qemu · Oct 19, 2023 · 4a0ca61 · 4a0ca61
1 parent f6ca9c1
commit 4a0ca61
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diff --git 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
@@ -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(),

diff --git 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;
 };