From a216c2ebd31a4fc230737678f6ba91580dac9a8b Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Wed, 8 Apr 2020 16:27:08 +0100
Subject: [PATCH] vm-virtio: pci: Implement free_bars() for VirtioPciDevice

Implement the free_bars() method from the PciDevice trait which is used
as part of the device removal process. Although there is only one BAR
allocated by VirtioPciDevice simplify the code by using a vector.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 vm-virtio/src/transport/pci_device.rs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/vm-virtio/src/transport/pci_device.rs b/vm-virtio/src/transport/pci_device.rs
index 482faea2d..76e048e28 100755
--- a/vm-virtio/src/transport/pci_device.rs
+++ b/vm-virtio/src/transport/pci_device.rs
@@ -300,6 +300,9 @@ pub struct VirtioPciDevice {
     // needed when the guest tries to early access the virtio configuration of
     // a device.
     cap_pci_cfg_info: VirtioPciCfgCapInfo,
+
+    // Details of bar regions to free
+    bar_regions: Vec<(GuestAddress, GuestUsize, PciBarRegionType)>,
 }
 
 impl VirtioPciDevice {
@@ -402,6 +405,7 @@ impl VirtioPciDevice {
             use_64bit_bar,
             interrupt_source_group,
             cap_pci_cfg_info: VirtioPciCfgCapInfo::default(),
+            bar_regions: vec![],
         };
 
         if let Some(msix_config) = &virtio_pci_device.msix_config {
@@ -721,6 +725,8 @@ impl PciDevice for VirtioPciDevice {
             ranges.push((addr, CAPABILITY_BAR_SIZE, region_type));
             (addr, region_type)
         };
+        self.bar_regions
+            .push((virtio_pci_bar_addr, CAPABILITY_BAR_SIZE, region_type));
 
         let config = PciBarConfiguration::default()
             .set_register_index(0)
@@ -763,6 +769,24 @@ impl PciDevice for VirtioPciDevice {
         Ok(ranges)
     }
 
+    fn free_bars(
+        &mut self,
+        allocator: &mut SystemAllocator,
+    ) -> std::result::Result<(), PciDeviceError> {
+        for (addr, length, type_) in self.bar_regions.drain(..) {
+            match type_ {
+                PciBarRegionType::Memory32BitRegion => {
+                    allocator.free_mmio_hole_addresses(addr, length);
+                }
+                PciBarRegionType::Memory64BitRegion => {
+                    allocator.free_mmio_addresses(addr, length);
+                }
+                _ => error!("Unexpected PCI bar type"),
+            }
+        }
+        Ok(())
+    }
+
     fn read_bar(&mut self, _base: u64, offset: u64, data: &mut [u8]) {
         match offset {
             o if o < COMMON_CONFIG_BAR_OFFSET + COMMON_CONFIG_SIZE => self.common_config.read(