[PATCH v2 01/10] backends: Introduce abstract HostIOMMUDevice

[Zhenzhong Duan <zhenzhong.duan@intel.com>]

Introduce HostIOMMUDevice as an abstraction of host IOMMU device.

get_host_iommu_info() is used to get host IOMMU info, different
backends can have different implementations and result format.

Introduce a macro CONFIG_HOST_IOMMU_DEVICE to define the usage
for VFIO, and VDPA in the future.

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 MAINTAINERS                        |  2 ++
 include/sysemu/host_iommu_device.h | 19 +++++++++++++++++++
 backends/host_iommu_device.c       | 19 +++++++++++++++++++
 backends/Kconfig                   |  5 +++++
 backends/meson.build               |  1 +
 5 files changed, 46 insertions(+)
 create mode 100644 include/sysemu/host_iommu_device.h
 create mode 100644 backends/host_iommu_device.c

diff --git a/MAINTAINERS b/MAINTAINERS
index e71183eef9..22f71cbe02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2202,6 +2202,8 @@ M: Zhenzhong Duan <zhenzhong.duan@intel.com>
 S: Supported
 F: backends/iommufd.c
 F: include/sysemu/iommufd.h
+F: backends/host_iommu_device.c
+F: include/sysemu/host_iommu_device.h
 F: include/qemu/chardev_open.h
 F: util/chardev_open.c
 F: docs/devel/vfio-iommufd.rst
diff --git a/include/sysemu/host_iommu_device.h b/include/sysemu/host_iommu_device.h
new file mode 100644
index 0000000000..22ccbe3a5d
--- /dev/null
+++ b/include/sysemu/host_iommu_device.h
@@ -0,0 +1,19 @@
+#ifndef HOST_IOMMU_DEVICE_H
+#define HOST_IOMMU_DEVICE_H
+
+#include "qom/object.h"
+
+#define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
+OBJECT_DECLARE_TYPE(HostIOMMUDevice, HostIOMMUDeviceClass, HOST_IOMMU_DEVICE)
+
+struct HostIOMMUDevice {
+    Object parent;
+};
+
+struct HostIOMMUDeviceClass {
+    ObjectClass parent_class;
+
+    int (*get_host_iommu_info)(HostIOMMUDevice *hiod, void *data, uint32_t len,
+                               Error **errp);
+};
+#endif
diff --git a/backends/host_iommu_device.c b/backends/host_iommu_device.c
new file mode 100644
index 0000000000..6cb6007d8c
--- /dev/null
+++ b/backends/host_iommu_device.c
@@ -0,0 +1,19 @@
+#include "qemu/osdep.h"
+#include "sysemu/host_iommu_device.h"
+
+OBJECT_DEFINE_ABSTRACT_TYPE(HostIOMMUDevice,
+                            host_iommu_device,
+                            HOST_IOMMU_DEVICE,
+                            OBJECT)
+
+static void host_iommu_device_class_init(ObjectClass *oc, void *data)
+{
+}
+
+static void host_iommu_device_init(Object *obj)
+{
+}
+
+static void host_iommu_device_finalize(Object *obj)
+{
+}
diff --git a/backends/Kconfig b/backends/Kconfig
index 2cb23f62fa..34ab29e994 100644
--- a/backends/Kconfig
+++ b/backends/Kconfig
@@ -3,3 +3,8 @@ source tpm/Kconfig
 config IOMMUFD
     bool
     depends on VFIO
+
+config HOST_IOMMU_DEVICE
+    bool
+    default y
+    depends on VFIO
diff --git a/backends/meson.build b/backends/meson.build
index 8b2b111497..2e975d641e 100644
--- a/backends/meson.build
+++ b/backends/meson.build
@@ -25,6 +25,7 @@ if have_vhost_user
 endif
 system_ss.add(when: 'CONFIG_VIRTIO_CRYPTO', if_true: files('cryptodev-vhost.c'))
 system_ss.add(when: 'CONFIG_IOMMUFD', if_true: files('iommufd.c'))
+system_ss.add(when: 'CONFIG_HOST_IOMMU_DEVICE', if_true: files('host_iommu_device.c'))
 if have_vhost_user_crypto
   system_ss.add(when: 'CONFIG_VIRTIO_CRYPTO', if_true: files('cryptodev-vhost-user.c'))
 endif
-- 
2.34.1