[PATCH rfcv3 02/21] vfio/iommufd: Add properties and handlers to TYPE_HOST_IOMMU_DEVICE_IOMMUFD

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

Enhance HostIOMMUDeviceIOMMUFD object with 3 new members, specific
to the iommufd BE + 2 new class functions.

IOMMUFD BE includes IOMMUFD handle, devid and hwpt_id. IOMMUFD handle
and devid are used to allocate/free ioas and hwpt. hwpt_id is used to
re-attach IOMMUFD backed device to its default VFIO sub-system created
hwpt, i.e., when vIOMMU is disabled by guest. These properties will be
initialized after attachment.

2 new class functions are [at|de]tach_hwpt(). They are used to
attach/detach hwpt. VFIO and VDPA can have different implementions,
so implementation will be in sub-class instead of HostIOMMUDeviceIOMMUFD,
e.g., in HostIOMMUDeviceIOMMUFDVFIO.

Add two wrappers host_iommu_device_iommufd_[at|de]tach_hwpt to
wrap the two functions.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/system/iommufd.h | 50 ++++++++++++++++++++++++++++++++++++++++
 backends/iommufd.c       | 22 ++++++++++++++++++
 2 files changed, 72 insertions(+)

diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index 5399519626..a704575662 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -67,4 +67,54 @@ bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
                                       Error **errp);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
+OBJECT_DECLARE_TYPE(HostIOMMUDeviceIOMMUFD, HostIOMMUDeviceIOMMUFDClass,
+                    HOST_IOMMU_DEVICE_IOMMUFD)
+
+/* Overload of the host IOMMU device for the iommufd backend */
+struct HostIOMMUDeviceIOMMUFD {
+    HostIOMMUDevice parent_obj;
+
+    IOMMUFDBackend *iommufd;
+    uint32_t devid;
+    uint32_t hwpt_id;
+};
+
+struct HostIOMMUDeviceIOMMUFDClass {
+    HostIOMMUDeviceClass parent_class;
+
+    /**
+     * @attach_hwpt: attach host IOMMU device to IOMMUFD hardware page table.
+     * VFIO and VDPA device can have different implementation.
+     *
+     * Mandatory callback.
+     *
+     * @idev: host IOMMU device backed by IOMMUFD backend.
+     *
+     * @hwpt_id: ID of IOMMUFD hardware page table.
+     *
+     * @errp: pass an Error out when attachment fails.
+     *
+     * Returns: true on success, false on failure.
+     */
+    bool (*attach_hwpt)(HostIOMMUDeviceIOMMUFD *idev, uint32_t hwpt_id,
+                        Error **errp);
+    /**
+     * @detach_hwpt: detach host IOMMU device from IOMMUFD hardware page table.
+     * VFIO and VDPA device can have different implementation.
+     *
+     * Mandatory callback.
+     *
+     * @idev: host IOMMU device backed by IOMMUFD backend.
+     *
+     * @errp: pass an Error out when attachment fails.
+     *
+     * Returns: true on success, false on failure.
+     */
+    bool (*detach_hwpt)(HostIOMMUDeviceIOMMUFD *idev, Error **errp);
+};
+
+bool host_iommu_device_iommufd_attach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
+                                           uint32_t hwpt_id, Error **errp);
+bool host_iommu_device_iommufd_detach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
+                                           Error **errp);
 #endif
diff --git a/backends/iommufd.c b/backends/iommufd.c
index c8788a6438..b114fb08e7 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -344,6 +344,26 @@ bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
     return !ret;
 }
 
+bool host_iommu_device_iommufd_attach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
+                                           uint32_t hwpt_id, Error **errp)
+{
+    HostIOMMUDeviceIOMMUFDClass *idevc =
+        HOST_IOMMU_DEVICE_IOMMUFD_GET_CLASS(idev);
+
+    g_assert(idevc->attach_hwpt);
+    return idevc->attach_hwpt(idev, hwpt_id, errp);
+}
+
+bool host_iommu_device_iommufd_detach_hwpt(HostIOMMUDeviceIOMMUFD *idev,
+                                           Error **errp)
+{
+    HostIOMMUDeviceIOMMUFDClass *idevc =
+        HOST_IOMMU_DEVICE_IOMMUFD_GET_CLASS(idev);
+
+    g_assert(idevc->detach_hwpt);
+    return idevc->detach_hwpt(idev, errp);
+}
+
 static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
 {
     HostIOMMUDeviceCaps *caps = &hiod->caps;
@@ -382,6 +402,8 @@ static const TypeInfo types[] = {
     }, {
         .name = TYPE_HOST_IOMMU_DEVICE_IOMMUFD,
         .parent = TYPE_HOST_IOMMU_DEVICE,
+        .instance_size = sizeof(HostIOMMUDeviceIOMMUFD),
+        .class_size = sizeof(HostIOMMUDeviceIOMMUFDClass),
         .class_init = hiod_iommufd_class_init,
         .abstract = true,
     }
-- 
2.34.1