[PULL 27/28] vfio: add vfio-pci-base class

["Cédric Le Goater" <clg@redhat.com>]

From: John Levon <john.levon@nutanix.com>

Split out parts of TYPE_VFIO_PCI into a base TYPE_VFIO_PCI_BASE,
although we have not yet introduced another subclass, so all the
properties have remained in TYPE_VFIO_PCI.

Note that currently there is no need for additional data for
TYPE_VFIO_PCI, so it shares the same C struct type as
TYPE_VFIO_PCI_BASE, VFIOPCIDevice.

Originally-by: John Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250507152020.1254632-14-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/vfio/pci.h    | 10 +++++++-
 hw/vfio/device.c |  2 +-
 hw/vfio/pci.c    | 62 +++++++++++++++++++++++++++++++-----------------
 3 files changed, 50 insertions(+), 24 deletions(-)

diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index f835b1dbc2b1e8aab820924900e1eb6c36613d16..5ce0fb916f3896a448b59fc0b99e892c11c3a9e1 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -118,8 +118,16 @@ typedef struct VFIOMSIXInfo {
     bool noresize;
 } VFIOMSIXInfo;
 
+/*
+ * TYPE_VFIO_PCI_BASE is an abstract type used to share code
+ * between VFIO implementations that use a kernel driver
+ * with those that use user sockets.
+ */
+#define TYPE_VFIO_PCI_BASE "vfio-pci-base"
+OBJECT_DECLARE_SIMPLE_TYPE(VFIOPCIDevice, VFIO_PCI_BASE)
+
 #define TYPE_VFIO_PCI "vfio-pci"
-OBJECT_DECLARE_SIMPLE_TYPE(VFIOPCIDevice, VFIO_PCI)
+/* TYPE_VFIO_PCI shares struct VFIOPCIDevice. */
 
 struct VFIOPCIDevice {
     PCIDevice pdev;
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 0b2cd90d64dc797bb2f20c60c57ff49706816aed..9fba2c7272f207f2fe870fc97b46c342bd57dc0a 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -392,7 +392,7 @@ bool vfio_device_hiod_create_and_realize(VFIODevice *vbasedev,
 VFIODevice *vfio_get_vfio_device(Object *obj)
 {
     if (object_dynamic_cast(obj, TYPE_VFIO_PCI)) {
-        return &VFIO_PCI(obj)->vbasedev;
+        return &VFIO_PCI_BASE(obj)->vbasedev;
     } else {
         return NULL;
     }
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 1236de315d1a73aa408c108e2e650a37b037b93e..a1bfdfe3751fdf171b0b96d78d0b51853d8e7838 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -241,7 +241,7 @@ static void vfio_intx_update(VFIOPCIDevice *vdev, PCIINTxRoute *route)
 
 static void vfio_intx_routing_notifier(PCIDevice *pdev)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     PCIINTxRoute route;
 
     if (vdev->interrupt != VFIO_INT_INTx) {
@@ -514,7 +514,7 @@ static void vfio_update_kvm_msi_virq(VFIOMSIVector *vector, MSIMessage msg,
 static int vfio_msix_vector_do_use(PCIDevice *pdev, unsigned int nr,
                                    MSIMessage *msg, IOHandler *handler)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIOMSIVector *vector;
     int ret;
     bool resizing = !!(vdev->nr_vectors < nr + 1);
@@ -620,7 +620,7 @@ static int vfio_msix_vector_use(PCIDevice *pdev,
 
 static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIOMSIVector *vector = &vdev->msi_vectors[nr];
 
     trace_vfio_msix_vector_release(vdev->vbasedev.name, nr);
@@ -1196,7 +1196,7 @@ static const MemoryRegionOps vfio_vga_ops = {
  */
 static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIORegion *region = &vdev->bars[bar].region;
     MemoryRegion *mmap_mr, *region_mr, *base_mr;
     PCIIORegion *r;
@@ -1242,7 +1242,7 @@ static void vfio_sub_page_bar_update_mapping(PCIDevice *pdev, int bar)
  */
 uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
     uint32_t emu_bits = 0, emu_val = 0, phys_val = 0, val;
 
@@ -1276,7 +1276,7 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
 void vfio_pci_write_config(PCIDevice *pdev,
                            uint32_t addr, uint32_t val, int len)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
     uint32_t val_le = cpu_to_le32(val);
     int ret;
@@ -3129,7 +3129,7 @@ static bool vfio_interrupt_setup(VFIOPCIDevice *vdev, Error **errp)
 static void vfio_realize(PCIDevice *pdev, Error **errp)
 {
     ERRP_GUARD();
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
     int i, ret;
     char uuid[UUID_STR_LEN];
@@ -3300,7 +3300,7 @@ error:
 
 static void vfio_instance_finalize(Object *obj)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(obj);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(obj);
 
     vfio_display_finalize(vdev);
     vfio_bars_finalize(vdev);
@@ -3318,7 +3318,7 @@ static void vfio_instance_finalize(Object *obj)
 
 static void vfio_exitfn(PCIDevice *pdev)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(pdev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(pdev);
     VFIODevice *vbasedev = &vdev->vbasedev;
 
     vfio_unregister_req_notifier(vdev);
@@ -3342,7 +3342,7 @@ static void vfio_exitfn(PCIDevice *pdev)
 
 static void vfio_pci_reset(DeviceState *dev)
 {
-    VFIOPCIDevice *vdev = VFIO_PCI(dev);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(dev);
 
     trace_vfio_pci_reset(vdev->vbasedev.name);
 
@@ -3382,7 +3382,7 @@ post_reset:
 static void vfio_instance_init(Object *obj)
 {
     PCIDevice *pci_dev = PCI_DEVICE(obj);
-    VFIOPCIDevice *vdev = VFIO_PCI(obj);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(obj);
     VFIODevice *vbasedev = &vdev->vbasedev;
 
     device_add_bootindex_property(obj, &vdev->bootindex,
@@ -3403,6 +3403,31 @@ static void vfio_instance_init(Object *obj)
     pci_dev->cap_present |= QEMU_PCI_CAP_EXPRESS;
 }
 
+static void vfio_pci_base_dev_class_init(ObjectClass *klass, const void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *pdc = PCI_DEVICE_CLASS(klass);
+
+    dc->desc = "VFIO PCI base device";
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    pdc->exit = vfio_exitfn;
+    pdc->config_read = vfio_pci_read_config;
+    pdc->config_write = vfio_pci_write_config;
+}
+
+static const TypeInfo vfio_pci_base_dev_info = {
+    .name = TYPE_VFIO_PCI_BASE,
+    .parent = TYPE_PCI_DEVICE,
+    .instance_size = 0,
+    .abstract = true,
+    .class_init = vfio_pci_base_dev_class_init,
+    .interfaces = (const InterfaceInfo[]) {
+        { INTERFACE_PCIE_DEVICE },
+        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
+        { }
+    },
+};
+
 static PropertyInfo vfio_pci_migration_multifd_transfer_prop;
 
 static const Property vfio_pci_dev_properties[] = {
@@ -3473,7 +3498,8 @@ static const Property vfio_pci_dev_properties[] = {
 #ifdef CONFIG_IOMMUFD
 static void vfio_pci_set_fd(Object *obj, const char *str, Error **errp)
 {
-    vfio_device_set_fd(&VFIO_PCI(obj)->vbasedev, str, errp);
+    VFIOPCIDevice *vdev = VFIO_PCI_BASE(obj);
+    vfio_device_set_fd(&vdev->vbasedev, str, errp);
 }
 #endif
 
@@ -3488,11 +3514,7 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, const void *data)
     object_class_property_add_str(klass, "fd", NULL, vfio_pci_set_fd);
 #endif
     dc->desc = "VFIO-based PCI device assignment";
-    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     pdc->realize = vfio_realize;
-    pdc->exit = vfio_exitfn;
-    pdc->config_read = vfio_pci_read_config;
-    pdc->config_write = vfio_pci_write_config;
 
     object_class_property_set_description(klass, /* 1.3 */
                                           "host",
@@ -3617,16 +3639,11 @@ static void vfio_pci_dev_class_init(ObjectClass *klass, const void *data)
 
 static const TypeInfo vfio_pci_dev_info = {
     .name = TYPE_VFIO_PCI,
-    .parent = TYPE_PCI_DEVICE,
+    .parent = TYPE_VFIO_PCI_BASE,
     .instance_size = sizeof(VFIOPCIDevice),
     .class_init = vfio_pci_dev_class_init,
     .instance_init = vfio_instance_init,
     .instance_finalize = vfio_instance_finalize,
-    .interfaces = (const InterfaceInfo[]) {
-        { INTERFACE_PCIE_DEVICE },
-        { INTERFACE_CONVENTIONAL_PCI_DEVICE },
-        { }
-    },
 };
 
 static const Property vfio_pci_dev_nohotplug_properties[] = {
@@ -3673,6 +3690,7 @@ static void register_vfio_pci_dev_type(void)
     vfio_pci_migration_multifd_transfer_prop = qdev_prop_on_off_auto;
     vfio_pci_migration_multifd_transfer_prop.realized_set_allowed = true;
 
+    type_register_static(&vfio_pci_base_dev_info);
     type_register_static(&vfio_pci_dev_info);
     type_register_static(&vfio_pci_nohotplug_dev_info);
 }
-- 
2.49.0