vfio/iommufd: Add framework code to support getting dirty bitmap before unmap

Currently we support device and iommu dirty tracking, device dirty tracking
is preferred.

Add the framework code in iommufd_cdev_unmap() to choose either device or
iommu dirty tracking, just like vfio_legacy_dma_unmap_one().

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Xudong Hao <xudong.hao@intel.com>
Tested-by: Giovannio Cabiddu <giovanni.cabiddu@intel.com>
Tested-by: Rohith S R <rohith.s.r@intel.com>
Link: https://lore.kernel.org/qemu-devel/20251218062643.624796-2-zhenzhong.duan@intel.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index e5328c63a366076199015b25f55d273b91a4327a..f56349faf5669cfeed10d7fc5e8d3bf8397bb04d 100644 (file)
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -61,14 +61,42 @@ static int iommufd_cdev_unmap(const VFIOContainer *bcontainer,
                               IOMMUTLBEntry *iotlb, bool unmap_all)
 {
     const VFIOIOMMUFDContainer *container = VFIO_IOMMU_IOMMUFD(bcontainer);
+    IOMMUFDBackend *be = container->be;
+    uint32_t ioas_id = container->ioas_id;
+    bool need_dirty_sync = false;
+    Error *local_err = NULL;
+    int ret;
 
     if (unmap_all) {
         size = UINT64_MAX;
     }
 
-    /* TODO: Handle dma_unmap_bitmap with iotlb args (migration) */
-    return iommufd_backend_unmap_dma(container->be,
-                                     container->ioas_id, iova, size);
+    if (iotlb && vfio_container_dirty_tracking_is_started(bcontainer)) {
+        if (!vfio_container_devices_dirty_tracking_is_supported(bcontainer) &&
+            bcontainer->dirty_pages_supported) {
+            /* TODO: query dirty bitmap before DMA unmap */
+            return iommufd_backend_unmap_dma(be, ioas_id, iova, size);
+        }
+
+        need_dirty_sync = true;
+    }
+
+    ret = iommufd_backend_unmap_dma(be, ioas_id, iova, size);
+    if (ret) {
+        return ret;
+    }
+
+    if (need_dirty_sync) {
+        ret = vfio_container_query_dirty_bitmap(bcontainer, iova, size,
+                                                iotlb->translated_addr,
+                                                &local_err);
+        if (ret) {
+            error_report_err(local_err);
+            return ret;
+        }
+    }
+
+    return 0;
 }
 
 static bool iommufd_cdev_kvm_device_add(VFIODevice *vbasedev, Error **errp)