diff --git a/vfio/src/vfio_device.rs b/vfio/src/vfio_device.rs
index 3e95295ae..e952f2086 100644
--- a/vfio/src/vfio_device.rs
+++ b/vfio/src/vfio_device.rs
@@ -25,7 +25,7 @@ use vfio_ioctls::*;
 use vm_device::{get_host_address_range, ExternalDmaMapping};
 use vm_memory::{
     Address, GuestAddress, GuestAddressSpace, GuestMemory, GuestMemoryAtomic, GuestMemoryMmap,
-    GuestMemoryRegion,
+    GuestMemoryRegion, GuestRegionMmap,
 };
 use vmm_sys_util::eventfd::EventFd;
 use vmm_sys_util::fam::FamStruct;
@@ -873,6 +873,18 @@ impl VfioDevice {
         Ok(())
     }
 
+    pub fn extend_dma_map(&self, new_region: &Arc<GuestRegionMmap>) -> Result<()> {
+        if !self.iommu_attached {
+            self.vfio_dma_map(
+                new_region.start_addr().raw_value(),
+                new_region.len() as u64,
+                new_region.as_ptr() as u64,
+            )
+        } else {
+            Ok(())
+        }
+    }
+
     /// Return the maximum numner of interrupts a VFIO device can request.
     /// This is used for pre-allocating the VFIO PCI routes.
     pub fn max_interrupts(&self) -> u32 {
diff --git a/vfio/src/vfio_pci.rs b/vfio/src/vfio_pci.rs
index d7a19f3c8..1582d5ea1 100644
--- a/vfio/src/vfio_pci.rs
+++ b/vfio/src/vfio_pci.rs
@@ -27,7 +27,7 @@ use vm_allocator::SystemAllocator;
 use vm_device::interrupt::{
     InterruptIndex, InterruptManager, InterruptSourceGroup, MsiIrqGroupConfig,
 };
-use vm_memory::{Address, GuestAddress, GuestUsize};
+use vm_memory::{Address, GuestAddress, GuestRegionMmap, GuestUsize};
 use vmm_sys_util::eventfd::EventFd;
 
 #[derive(Debug)]
@@ -41,6 +41,7 @@ pub enum VfioPciError {
     SetGsiRouting(kvm_ioctls::Error),
     MsiNotConfigured,
     MsixNotConfigured,
+    UpdateMemory(crate::VfioError),
     UpdateMsiEventFd,
     UpdateMsixEventFd,
 }
@@ -62,6 +63,7 @@ impl fmt::Display for VfioPciError {
             VfioPciError::SetGsiRouting(e) => write!(f, "failed to set GSI routes for KVM: {}", e),
             VfioPciError::MsiNotConfigured => write!(f, "MSI interrupt not yet configured"),
             VfioPciError::MsixNotConfigured => write!(f, "MSI-X interrupt not yet configured"),
+            VfioPciError::UpdateMemory(e) => write!(f, "failed to update memory: {}", e),
             VfioPciError::UpdateMsiEventFd => write!(f, "failed to update MSI eventfd"),
             VfioPciError::UpdateMsixEventFd => write!(f, "failed to update MSI-X eventfd"),
         }
@@ -610,6 +612,12 @@ impl VfioPciDevice {
             }
         }
     }
+
+    pub fn update_memory(&self, new_region: &Arc<GuestRegionMmap>) -> Result<()> {
+        self.device
+            .extend_dma_map(new_region)
+            .map_err(VfioPciError::UpdateMemory)
+    }
 }
 
 impl Drop for VfioPciDevice {