When both host device and vIOMMU have PASID enabled, then guest may
setup pasid attached translation.

We need to create the nesting parent hwpt with IOMMU_HWPT_ALLOC_PASID
flag because according to uAPI, any domain attached to the non-PASID
part of the device must also be flagged, otherwise attaching a PASID
will blocked.

Introduce a vfio_device_get_viommu_flags_pasid_supported() helper to
facilitate this implementation.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/hw/vfio/vfio-device.h |  1 +
 hw/vfio/device.c              | 11 +++++++++++
 hw/vfio/iommufd.c             |  8 +++++++-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/include/hw/vfio/vfio-device.h b/include/hw/vfio/vfio-device.h
index 35a5ec6d92..983eb0ecce 100644
--- a/include/hw/vfio/vfio-device.h
+++ b/include/hw/vfio/vfio-device.h
@@ -268,6 +268,7 @@ void vfio_device_prepare(VFIODevice *vbasedev, VFIOContainer *bcontainer,
 void vfio_device_unprepare(VFIODevice *vbasedev);
 
 bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev);
+bool vfio_device_get_viommu_flags_pasid_supported(VFIODevice *vbasedev);
 bool vfio_device_get_host_iommu_quirk_bypass_ro(VFIODevice *vbasedev,
                                                 uint32_t type, void *caps,
                                                 uint32_t size);
diff --git a/hw/vfio/device.c b/hw/vfio/device.c
index 973fc35b59..b15ca6ef0a 100644
--- a/hw/vfio/device.c
+++ b/hw/vfio/device.c
@@ -533,6 +533,17 @@ bool vfio_device_get_viommu_flags_want_nesting(VFIODevice *vbasedev)
     return false;
 }
 
+bool vfio_device_get_viommu_flags_pasid_supported(VFIODevice *vbasedev)
+{
+    VFIOPCIDevice *vdev = vfio_pci_from_vfio_device(vbasedev);
+
+    if (vdev) {
+        return !!(pci_device_get_viommu_flags(PCI_DEVICE(vdev)) &
+                  VIOMMU_FLAG_PASID_SUPPORTED);
+    }
+    return false;
+}
+
 bool vfio_device_get_host_iommu_quirk_bypass_ro(VFIODevice *vbasedev,
                                                 uint32_t type, void *caps,
                                                 uint32_t size)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 96735f1fc8..9605bf73b7 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -354,6 +354,7 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
     VendorCaps caps;
     VFIOIOASHwpt *hwpt;
     uint32_t hwpt_id;
+    uint8_t max_pasid_log2;
     int ret;
 
     /* Try to find a domain */
@@ -398,7 +399,7 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
      */
     if (!iommufd_backend_get_device_info(vbasedev->iommufd, vbasedev->devid,
                                          &type, &caps, sizeof(caps), &hw_caps,
-                                         NULL, errp)) {
+                                         &max_pasid_log2, errp)) {
         return false;
     }
 
@@ -420,6 +421,11 @@ static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
         }
     }
 
+    if (max_pasid_log2 &&
+        vfio_device_get_viommu_flags_pasid_supported(vbasedev)) {
+        flags |= IOMMU_HWPT_ALLOC_PASID;
+    }
+
     if (cpr_is_incoming()) {
         hwpt_id = vbasedev->cpr.hwpt_id;
         goto skip_alloc;
-- 
2.47.3