Move viommu teardown into a helper function and use it from the
last device removal path.

This groups related cleanup logic in one place and improves readability.
It also makes it easier to extend the teardown in future, for example
when freeing related objects such as vEVENTQ.

No functional change.

Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Shameer Kolothum <skolothumtho@nvidia.com>
---
 hw/arm/smmuv3-accel.c | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/hw/arm/smmuv3-accel.c b/hw/arm/smmuv3-accel.c
index f5cd4df336..c19c526fca 100644
--- a/hw/arm/smmuv3-accel.c
+++ b/hw/arm/smmuv3-accel.c
@@ -390,6 +390,20 @@ bool smmuv3_accel_issue_inv_cmd(SMMUv3State *bs, void *cmd, SMMUDevice *sdev,
                    sizeof(Cmd), &entry_num, cmd, errp);
 }
 
+static void smmuv3_accel_free_viommu(SMMUv3AccelState *accel)
+{
+    IOMMUFDViommu *viommu = accel->viommu;
+
+    if (!viommu) {
+        return;
+    }
+    iommufd_backend_free_id(viommu->iommufd, accel->bypass_hwpt_id);
+    iommufd_backend_free_id(viommu->iommufd, accel->abort_hwpt_id);
+    iommufd_backend_free_id(viommu->iommufd, accel->viommu->viommu_id);
+    g_free(viommu);
+    accel->viommu = NULL;
+}
+
 static bool
 smmuv3_accel_alloc_viommu(SMMUv3State *s, HostIOMMUDeviceIOMMUFD *idev,
                           Error **errp)
@@ -549,12 +563,7 @@ static void smmuv3_accel_unset_iommu_device(PCIBus *bus, void *opaque,
     trace_smmuv3_accel_unset_iommu_device(devfn, idev->devid);
 
     if (QLIST_EMPTY(&accel->device_list)) {
-        iommufd_backend_free_id(accel->viommu->iommufd, accel->bypass_hwpt_id);
-        iommufd_backend_free_id(accel->viommu->iommufd, accel->abort_hwpt_id);
-        iommufd_backend_free_id(accel->viommu->iommufd,
-                                accel->viommu->viommu_id);
-        g_free(accel->viommu);
-        accel->viommu = NULL;
+        smmuv3_accel_free_viommu(accel);
     }
 }
 
-- 
2.43.0