The nubus-virtio-mmio device is a Nubus card that contains a set of 32 virtio-mmio
devices and a goldfish PIC similar to the m68k virt machine that can be plugged
into the m68k q800 machine.

There are currently a number of drivers under development that can be used in
conjunction with this device to provide accelerated and/or additional hypervisor
services to 68k Classic MacOS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/nubus/meson.build                 |   1 +
 hw/nubus/nubus-virtio-mmio.c         | 102 +++++++++++++++++++++++++++
 include/hw/nubus/nubus-virtio-mmio.h |  36 ++++++++++
 3 files changed, 139 insertions(+)
 create mode 100644 hw/nubus/nubus-virtio-mmio.c
 create mode 100644 include/hw/nubus/nubus-virtio-mmio.h

diff --git a/hw/nubus/meson.build b/hw/nubus/meson.build
index e7ebda8993..9a7a12ea68 100644
--- a/hw/nubus/meson.build
+++ b/hw/nubus/meson.build
@@ -2,6 +2,7 @@ nubus_ss = ss.source_set()
 nubus_ss.add(files('nubus-device.c'))
 nubus_ss.add(files('nubus-bus.c'))
 nubus_ss.add(files('nubus-bridge.c'))
+nubus_ss.add(files('nubus-virtio-mmio.c'))
 nubus_ss.add(when: 'CONFIG_Q800', if_true: files('mac-nubus-bridge.c'))
 
 system_ss.add_all(when: 'CONFIG_NUBUS', if_true: nubus_ss)
diff --git a/hw/nubus/nubus-virtio-mmio.c b/hw/nubus/nubus-virtio-mmio.c
new file mode 100644
index 0000000000..58a63c84d0
--- /dev/null
+++ b/hw/nubus/nubus-virtio-mmio.c
@@ -0,0 +1,102 @@
+/*
+ * QEMU Macintosh Nubus Virtio MMIO card
+ *
+ * Copyright (c) 2024 Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "hw/nubus/nubus-virtio-mmio.h"
+
+
+#define NUBUS_VIRTIO_MMIO_PIC_OFFSET   0
+#define NUBUS_VIRTIO_MMIO_DEV_OFFSET   0x200
+
+
+static void nubus_virtio_mmio_set_input_irq(void *opaque, int n, int level)
+{
+    NubusDevice *nd = NUBUS_DEVICE(opaque);
+
+    nubus_set_irq(nd, level);
+}
+
+static void nubus_virtio_mmio_realize(DeviceState *dev, Error **errp)
+{
+    NubusVirtioMMIODeviceClass *nvmdc = NUBUS_VIRTIO_MMIO_GET_CLASS(dev);
+    NubusVirtioMMIO *s = NUBUS_VIRTIO_MMIO(dev);
+    NubusDevice *nd = NUBUS_DEVICE(dev);
+    SysBusDevice *sbd;
+    int i, offset;
+
+    nvmdc->parent_realize(dev, errp);
+    if (*errp) {
+        return;
+    }
+
+    /* Goldfish PIC */
+    sbd = SYS_BUS_DEVICE(&s->pic);
+    if (!sysbus_realize(sbd, errp)) {
+        return;
+    }
+    memory_region_add_subregion(&nd->slot_mem, NUBUS_VIRTIO_MMIO_PIC_OFFSET,
+                                sysbus_mmio_get_region(sbd, 0));
+    sysbus_connect_irq(sbd, 0,
+                       qdev_get_gpio_in_named(dev, "pic-input-irq", 0));
+
+    /* virtio-mmio devices */
+    offset = NUBUS_VIRTIO_MMIO_DEV_OFFSET;
+    for (i = 0; i < NUBUS_VIRTIO_MMIO_NUM_DEVICES; i++) {
+        sbd = SYS_BUS_DEVICE(&s->virtio_mmio[i]);
+        qdev_prop_set_bit(DEVICE(sbd), "force-legacy", false);
+        if (!sysbus_realize_and_unref(sbd, errp)) {
+            return;
+        }
+
+        memory_region_add_subregion(&nd->slot_mem, offset,
+                                    sysbus_mmio_get_region(sbd, 0));
+        offset += 0x200;
+
+        sysbus_connect_irq(sbd, 0, qdev_get_gpio_in(DEVICE(&s->pic), i));
+    }
+}
+
+static void nubus_virtio_mmio_init(Object *obj)
+{
+    NubusVirtioMMIO *s = NUBUS_VIRTIO_MMIO(obj);
+    int i;
+
+    object_initialize_child(obj, "pic", &s->pic, TYPE_GOLDFISH_PIC);
+    for (i = 0; i < NUBUS_VIRTIO_MMIO_NUM_DEVICES; i++) {
+        char *name = g_strdup_printf("virtio-mmio[%d]", i);
+        object_initialize_child(obj, name, &s->virtio_mmio[i],
+                                TYPE_VIRTIO_MMIO);
+        g_free(name);
+    }
+
+    /* Input from goldfish PIC */
+    qdev_init_gpio_in_named(DEVICE(obj), nubus_virtio_mmio_set_input_irq,
+                            "pic-input-irq", 1);
+}
+
+static void nubus_virtio_mmio_class_init(ObjectClass *oc, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(oc);
+    NubusVirtioMMIODeviceClass *nvmdc = NUBUS_VIRTIO_MMIO_CLASS(oc);
+
+    device_class_set_parent_realize(dc, nubus_virtio_mmio_realize,
+                                    &nvmdc->parent_realize);
+}
+
+static const TypeInfo nubus_virtio_mmio_types[] = {
+    {
+        .name = TYPE_NUBUS_VIRTIO_MMIO,
+        .parent = TYPE_NUBUS_DEVICE,
+        .instance_init = nubus_virtio_mmio_init,
+        .instance_size = sizeof(NubusVirtioMMIO),
+        .class_init = nubus_virtio_mmio_class_init,
+        .class_size = sizeof(NubusVirtioMMIODeviceClass),
+    },
+};
+
+DEFINE_TYPES(nubus_virtio_mmio_types)
diff --git a/include/hw/nubus/nubus-virtio-mmio.h b/include/hw/nubus/nubus-virtio-mmio.h
new file mode 100644
index 0000000000..de497b7f76
--- /dev/null
+++ b/include/hw/nubus/nubus-virtio-mmio.h
@@ -0,0 +1,36 @@
+/*
+ * QEMU Macintosh Nubus Virtio MMIO card
+ *
+ * Copyright (c) 2023 Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_NUBUS_VIRTIO_MMIO_H
+#define HW_NUBUS_VIRTIO_MMIO_H
+
+#include "hw/nubus/nubus.h"
+#include "qom/object.h"
+#include "hw/intc/goldfish_pic.h"
+#include "hw/virtio/virtio-mmio.h"
+
+#define TYPE_NUBUS_VIRTIO_MMIO "nubus-virtio-mmio"
+OBJECT_DECLARE_TYPE(NubusVirtioMMIO, NubusVirtioMMIODeviceClass,
+                    NUBUS_VIRTIO_MMIO)
+
+struct NubusVirtioMMIODeviceClass {
+    DeviceClass parent_class;
+
+    DeviceRealize parent_realize;
+};
+
+#define NUBUS_VIRTIO_MMIO_NUM_DEVICES 32
+
+struct NubusVirtioMMIO {
+    NubusDevice parent_obj;
+
+    GoldfishPICState pic;
+    VirtIOMMIOProxy virtio_mmio[NUBUS_VIRTIO_MMIO_NUM_DEVICES];
+};
+
+#endif
-- 
2.39.2