diff --git a/src/device/blk.rs b/src/device/blk.rs
index f3aa3054..a718c383 100644
--- a/src/device/blk.rs
+++ b/src/device/blk.rs
@@ -378,6 +378,16 @@ impl<H: Hal, T: Transport> VirtIOBlk<H, T> {
     pub fn virt_queue_size(&self) -> u16 {
         QUEUE_SIZE
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 impl<H: Hal, T: Transport> Drop for VirtIOBlk<H, T> {
diff --git a/src/device/console.rs b/src/device/console.rs
index 4ee54bd0..d591e643 100644
--- a/src/device/console.rs
+++ b/src/device/console.rs
@@ -246,6 +246,16 @@ impl<H: Hal, T: Transport> VirtIOConsole<H, T> {
             Err(Error::Unsupported)
         }
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 impl<H: Hal, T: Transport> Write for VirtIOConsole<H, T> {
diff --git a/src/device/gpu.rs b/src/device/gpu.rs
index 707a6c60..738a18d7 100644
--- a/src/device/gpu.rs
+++ b/src/device/gpu.rs
@@ -181,6 +181,16 @@ impl<H: Hal, T: Transport> VirtIOGpu<H, T> {
         Ok(())
     }
 
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
+
     /// Send a request to the device and block for a response.
     fn request<Req: IntoBytes + Immutable, Rsp: FromBytes>(&mut self, req: Req) -> Result<Rsp> {
         req.write_to_prefix(&mut self.queue_buf_send).unwrap();
diff --git a/src/device/input.rs b/src/device/input.rs
index 69171699..4fab4237 100644
--- a/src/device/input.rs
+++ b/src/device/input.rs
@@ -196,6 +196,16 @@ impl<H: Hal, T: Transport> VirtIOInput<H, T> {
             Err(Error::IoError)
         }
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 // SAFETY: The config space can be accessed from any thread.
diff --git a/src/device/net/dev.rs b/src/device/net/dev.rs
index 287b2a55..838a0d5d 100644
--- a/src/device/net/dev.rs
+++ b/src/device/net/dev.rs
@@ -122,4 +122,14 @@ impl<H: Hal, T: Transport, const QUEUE_SIZE: usize> VirtIONet<H, T, QUEUE_SIZE>
     pub fn send(&mut self, tx_buf: TxBuffer) -> Result {
         self.inner.send(tx_buf.packet())
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        self.inner.transport()
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        self.inner.transport_mut()
+    }
 }
diff --git a/src/device/net/dev_raw.rs b/src/device/net/dev_raw.rs
index c85c7ea3..d9438355 100644
--- a/src/device/net/dev_raw.rs
+++ b/src/device/net/dev_raw.rs
@@ -266,6 +266,16 @@ impl<H: Hal, T: Transport, const QUEUE_SIZE: usize> VirtIONetRaw<H, T, QUEUE_SIZ
         // SAFETY: This `rx_buf` is the same one passed to `receive_begin`.
         unsafe { self.receive_complete(token, rx_buf) }
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 impl<H: Hal, T: Transport, const QUEUE_SIZE: usize> Drop for VirtIONetRaw<H, T, QUEUE_SIZE> {
diff --git a/src/device/rng.rs b/src/device/rng.rs
index 3ced8a2f..063ff1ae 100644
--- a/src/device/rng.rs
+++ b/src/device/rng.rs
@@ -49,6 +49,16 @@ impl<H: Hal, T: Transport> VirtIORng<H, T> {
     pub fn ack_interrupt(&mut self) -> bool {
         self.transport.ack_interrupt()
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 impl<H: Hal, T: Transport> Drop for VirtIORng<H, T> {
diff --git a/src/device/socket/vsock.rs b/src/device/socket/vsock.rs
index 53e8634b..fe6e4ee5 100644
--- a/src/device/socket/vsock.rs
+++ b/src/device/socket/vsock.rs
@@ -424,6 +424,16 @@ impl<H: Hal, T: Transport, const RX_BUFFER_SIZE: usize> VirtIOSocket<H, T, RX_BU
         Ok(())
     }
 
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
+
     fn send_packet_to_tx_queue(&mut self, header: &VirtioVsockHdr, buffer: &[u8]) -> Result {
         let _len = if buffer.is_empty() {
             self.tx
diff --git a/src/device/sound.rs b/src/device/sound.rs
index 5b4c641b..27545405 100644
--- a/src/device/sound.rs
+++ b/src/device/sound.rs
@@ -726,6 +726,16 @@ impl<H: Hal, T: Transport> VirtIOSound<H, T> {
             }
         })
     }
+
+    /// Get the underlying transport.
+    pub fn transport(&self) -> &T {
+        &self.transport
+    }
+
+    /// Get the underlying transport.
+    pub fn transport_mut(&mut self) -> &mut T {
+        &mut self.transport
+    }
 }
 
 /// The status of the PCM stream.
diff --git a/src/transport/pci.rs b/src/transport/pci.rs
index 1b323999..7c33177c 100644
--- a/src/transport/pci.rs
+++ b/src/transport/pci.rs
@@ -366,6 +366,30 @@ impl Transport for PciTransport {
     }
 }
 
+impl PciTransport {
+    /// Get the MSI-X vector for config.
+    pub fn get_config_msix_vector(&self) -> u16 {
+        field_shared!(self.common_cfg, config_msix_vector).read()
+    }
+
+    /// Set the MSI-X vector for config.
+    pub fn set_config_msix_vector(&mut self, vector: u16) {
+        field!(self.common_cfg, config_msix_vector).write(vector);
+    }
+
+    /// Get the MSI-X vector for a queue.
+    pub fn get_queue_msix_vector(&mut self, queue: u16) -> u16 {
+        field!(self.common_cfg, queue_select).write(queue);
+        field_shared!(self.common_cfg, queue_msix_vector).read()
+    }
+
+    /// Set the MSI-X vector for a queue.
+    pub fn set_queue_msix_vector(&mut self, queue: u16, vector: u16) {
+        field!(self.common_cfg, queue_select).write(queue);
+        field!(self.common_cfg, queue_msix_vector).write(vector);
+    }
+}
+
 // SAFETY: MMIO can be done from any thread or CPU core.
 unsafe impl Send for PciTransport {}
 
@@ -388,7 +412,7 @@ pub(crate) struct CommonCfg {
     pub device_feature: ReadPure<u32>,
     pub driver_feature_select: ReadPureWrite<u32>,
     pub driver_feature: ReadPureWrite<u32>,
-    pub msix_config: ReadPureWrite<u16>,
+    pub config_msix_vector: ReadPureWrite<u16>,
     pub num_queues: ReadPure<u16>,
     pub device_status: ReadPureWrite<u8>,
     pub config_generation: ReadPure<u8>,