pci: Detect BAR reprogramming

Based on the value being written to the BAR, the implementation can
now detect if the BAR is being moved to another address. If that is the
case, it invokes move_bar() function from the DeviceRelocation trait.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

vm-virtio/src/transport/pci_device.rs

@@ -19,10 +19,10 @@ use std::sync::{Arc, Mutex, RwLock};
 
 use devices::BusDevice;
 use pci::{
-    InterruptDelivery, InterruptParameters, MsixCap, MsixConfig, PciBarConfiguration,
-    PciBarRegionType, PciCapability, PciCapabilityID, PciClassCode, PciConfiguration, PciDevice,
-    PciDeviceError, PciHeaderType, PciInterruptPin, PciMassStorageSubclass,
-    PciNetworkControllerSubclass, PciSubclass,
+    BarReprogrammingParams, InterruptDelivery, InterruptParameters, MsixCap, MsixConfig,
+    PciBarConfiguration, PciBarRegionType, PciCapability, PciCapabilityID, PciClassCode,
+    PciConfiguration, PciDevice, PciDeviceError, PciHeaderType, PciInterruptPin,
+    PciMassStorageSubclass, PciNetworkControllerSubclass, PciSubclass,
 };
 use vm_allocator::SystemAllocator;
 use vm_memory::{Address, ByteValued, GuestAddress, GuestMemoryMmap, GuestUsize, Le32};
@@ -520,6 +520,14 @@ impl PciDevice for VirtioPciDevice {
         self.configuration.read_reg(reg_idx)
     }
 
+    fn detect_bar_reprogramming(
+        &mut self,
+        reg_idx: usize,
+        data: &[u8],
+    ) -> Option<BarReprogrammingParams> {
+        self.configuration.detect_bar_reprogramming(reg_idx, data)
+    }
+
     fn ioeventfds(&self) -> Vec<(&EventFd, u64, u64)> {
         let bar0 = self.configuration.get_bar_addr(self.settings_bar as usize);
         let notify_base = bar0 + NOTIFICATION_BAR_OFFSET;