On 10/17/25 10:22, Zhenzhong Duan wrote:
When a existing mapping is unmapped, there could already be dirty bits
which need to be recorded before unmap.
If query dirty bitmap fails, we still need to do unmapping or else there
is stale mapping and it's risky to guest.
Co-developed-by: Joao Martins <[email protected]>
Signed-off-by: Joao Martins <[email protected]>
Signed-off-by: Zhenzhong Duan <[email protected]>
Tested-by: Xudong Hao <[email protected]>
Tested-by: Giovannio Cabiddu <[email protected]>
---
hw/vfio/iommufd.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 976c0a8814..404e6249ca 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -74,7 +74,13 @@ static int iommufd_cdev_unmap(const VFIOContainer
*bcontainer,
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 */
+ ret = vfio_container_query_dirty_bitmap(bcontainer, iova, size,
+ iotlb->translated_addr,
+ &local_err);
+ if (ret) {
+ error_report_err(local_err);
+ }
+ /* Unmap stale mapping even if query dirty bitmap fails */
return iommufd_backend_unmap_dma(be, ioas_id, iova, size);
}
Reviewed-by: Cédric Le Goater <[email protected]>
Thanks,
C.
