[PATCH v2 04/19] vfio/iommufd: Force creating nested parent domain

[Zhenzhong Duan]

Call pci_device_get_viommu_cap() to get if vIOMMU supports VIOMMU_CAP_STAGE1,
if yes, create nested parent domain which could be reused by vIOMMU to create
nested domain.

Suggested-by: Nicolin Chen <nicol...@nvidia.com>
Suggested-by: Yi Liu <yi.l....@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
 hw/vfio/iommufd.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index d3efef71af..83a632bdee 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -20,6 +20,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "system/iommufd.h"
+#include "hw/iommu.h"
 #include "hw/qdev-core.h"
 #include "hw/vfio/vfio-cpr.h"
 #include "system/reset.h"
@@ -352,6 +353,19 @@ static bool iommufd_cdev_autodomains_get(VFIODevice 
*vbasedev,
         flags = IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
     }
 
+    /*
+     * If vIOMMU supports stage-1 translation, force to create nested parent
+     * domain which could be reused by vIOMMU to create nested domain.
+     */
+    if (vbasedev->type == VFIO_DEVICE_TYPE_PCI) {
+        VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
+
+        hw_caps = pci_device_get_viommu_cap(&vdev->pdev);
+        if (hw_caps & VIOMMU_CAP_STAGE1) {
+            flags |= IOMMU_HWPT_ALLOC_NEST_PARENT;
+        }
+    }
+
     if (!iommufd_backend_alloc_hwpt(iommufd, vbasedev->devid,
                                     container->ioas_id, flags,
                                     IOMMU_HWPT_DATA_NONE, 0, NULL,
-- 
2.34.1