vfio/{iommufd, container}: Invoke HostIOMMUDevice::realize() during attach_device()

Move the HostIOMMUDevice::realize() to be invoked during the attach of the device
before we allocate IOMMUFD hardware pagetable objects (HWPT). This allows the use
of the hw_caps obtained by IOMMU_GET_HW_INFO that essentially tell if the IOMMU
behind the device supports dirty tracking.

Note: The HostIOMMUDevice data from legacy backend is static and doesn't
need any information from the (type1-iommu) backend to be initialized.
In contrast however, the IOMMUFD HostIOMMUDevice data requires the
iommufd FD to be connected and having a devid to be able to successfully
GET_HW_INFO. This means vfio_device_hiod_realize() is called in
different places within the backend .attach_device() implementation.

Suggested-by: Cédric Le Goater <clg@redhat.cm>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
[ clg: Fixed error handling in iommufd_cdev_attach() ]
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index fb87e64e44..798c4798a5 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -404,6 +404,17 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
 
     space = vfio_get_address_space(as);
 
+    /*
+     * The HostIOMMUDevice data from legacy backend is static and doesn't need
+     * any information from the (type1-iommu) backend to be initialized. In
+     * contrast however, the IOMMUFD HostIOMMUDevice data requires the iommufd
+     * FD to be connected and having a devid to be able to successfully call
+     * iommufd_backend_get_device_info().
+     */
+    if (!vfio_device_hiod_realize(vbasedev, errp)) {
+        goto err_alloc_ioas;
+    }
+
     /* try to attach to an existing container in this space */
     QLIST_FOREACH(bcontainer, &space->containers, next) {
         container = container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);