devices: pci: support hotplugged pci bus to be removed from tree
When pcie switch get removed from the system, we need to remove
their pci buses. This patch adds a new bool field in PciBus
structure to mark it as a hotplug bus and add support to remove
a pci bus from a pci bus tree. Also some other helper functions
is added for hotplug out usage.
BUG=b:199986018
TEST=./tools/presubmit
Change-Id: I71064127345424bf050d993f60f9d766a299de8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3709793
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/arch/src/lib.rs b/arch/src/lib.rs
index ec9f681..50d140a 100644
--- a/arch/src/lib.rs
+++ b/arch/src/lib.rs
@@ -640,7 +640,7 @@
let mut device_ranges = BTreeMap::new();
let mut io_ranges = BTreeMap::new();
- let root_bus = Arc::new(Mutex::new(PciBus::new(0, 0)));
+ let root_bus = Arc::new(Mutex::new(PciBus::new(0, 0, false)));
generate_pci_topology(
root_bus.clone(),
diff --git a/devices/src/pci/pci_device.rs b/devices/src/pci/pci_device.rs
index 64263ab..61487be 100644
--- a/devices/src/pci/pci_device.rs
+++ b/devices/src/pci/pci_device.rs
@@ -31,8 +31,8 @@
#[sorted]
#[derive(Error, Debug)]
pub enum Error {
- /// Device does not located on this bus
- #[error("pci device {0} does not located on bus {1}")]
+ /// Added pci device's parent bus does not belong to this bus
+ #[error("pci device {0}'s parent bus does not belong to bus {1}")]
AddedDeviceBusNotExist(PciAddress, u8),
/// Invalid alignment encountered.
#[error("Alignment must be a power of 2")]
@@ -40,6 +40,9 @@
/// The new bus has already been added to this bus
#[error("Added bus {0} already existed on bus {1}")]
BusAlreadyExist(u8, u8),
+ /// Target bus not exists on this bus
+ #[error("pci bus {0} does not exist on bus {1}")]
+ BusNotExist(u8, u8),
/// Setup of the device capabilities failed.
#[error("failed to add capability {0}")]
CapabilitiesSetup(pci_configuration::Error),
@@ -54,7 +57,9 @@
/// Device is already on this bus
#[error("pci device {0} has already been added to bus {1}")]
DeviceAlreadyExist(PciAddress, u8),
-
+ /// Device not exist on this bus
+ #[error("pci device {0} does not located on bus {1}")]
+ DeviceNotExist(PciAddress, u8),
/// Allocating space for an IO BAR failed.
#[error("failed to allocate space for an IO BAR, size={0}: {1}")]
IoAllocationFailed(u64, SystemAllocatorFaliure),
@@ -112,20 +117,27 @@
// Hash map that stores all direct child buses of this bus.
// It maps from child bus number to its pci bus structure.
child_buses: HashMap<u8, Arc<Mutex<PciBus>>>,
+ // Is hotplug bus
+ hotplug_bus: bool,
}
impl PciBus {
// Creates a new pci bus
- pub fn new(bus_num: u8, parent_bus_num: u8) -> Self {
+ pub fn new(bus_num: u8, parent_bus_num: u8, hotplug_bus: bool) -> Self {
PciBus {
bus_num,
parent_bus_num,
child_devices: HashSet::new(),
child_buses: HashMap::new(),
+ hotplug_bus,
}
}
- // Add a new child device to this pci bus tree recursively.
+ pub fn get_bus_num(&self) -> u8 {
+ self.bus_num
+ }
+
+ // Add a new child device to this pci bus tree.
pub fn add_child_device(&mut self, add_device: PciAddress) -> Result<()> {
if self.bus_num == add_device.bus {
if !self.child_devices.insert(add_device) {
@@ -147,7 +159,20 @@
Err(Error::AddedDeviceBusNotExist(add_device, self.bus_num))
}
- // Add a new child bus to this pci bus tree recursively.
+ // Remove one child device from this pci bus tree
+ pub fn remove_child_device(&mut self, device: PciAddress) -> Result<()> {
+ if self.child_devices.remove(&device) {
+ return Ok(());
+ }
+ for child_bus in self.child_buses.values() {
+ if child_bus.lock().remove_child_device(device).is_ok() {
+ return Ok(());
+ }
+ }
+ Err(Error::DeviceNotExist(device, self.bus_num))
+ }
+
+ // Add a new child bus to this pci bus tree.
pub fn add_child_bus(&mut self, add_bus: Arc<Mutex<PciBus>>) -> Result<()> {
let add_bus_num = add_bus.lock().bus_num;
let add_bus_parent = add_bus.lock().parent_bus_num;
@@ -172,6 +197,34 @@
Err(Error::ParentBusNotExist(add_bus_num, self.bus_num))
}
+ // Remove one child bus from this pci bus tree.
+ pub fn remove_child_bus(&mut self, bus_no: u8) -> Result<()> {
+ if self.child_buses.remove(&bus_no).is_some() {
+ return Ok(());
+ }
+ for (_, child_bus) in self.child_buses.iter() {
+ if child_bus.lock().remove_child_bus(bus_no).is_ok() {
+ return Ok(());
+ }
+ }
+ Err(Error::BusNotExist(bus_no, self.bus_num))
+ }
+
+ // Find all downstream devices under the given bus
+ pub fn find_downstream_devices(&self, bus_no: u8) -> Vec<PciAddress> {
+ if self.bus_num == bus_no {
+ return self.get_downstream_devices();
+ }
+ for (_, child_bus) in self.child_buses.iter() {
+ let res = child_bus.lock().find_downstream_devices(bus_no);
+ if !res.is_empty() {
+ return res;
+ }
+ }
+
+ Vec::new()
+ }
+
// Get all devices in this pci bus tree
pub fn get_downstream_devices(&self) -> Vec<PciAddress> {
let mut devices = Vec::new();
@@ -182,8 +235,33 @@
devices
}
- pub fn get_bus_num(&self) -> u8 {
- self.bus_num
+ // Check if given device is located in the device tree
+ pub fn contains(&self, device: PciAddress) -> bool {
+ if self.child_devices.contains(&device) {
+ return true;
+ }
+
+ for (_, child_bus) in self.child_buses.iter() {
+ if child_bus.lock().contains(device) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ // Returns the hotplug bus that this device is on.
+ pub fn get_hotplug_bus(&self, device: PciAddress) -> Option<u8> {
+ if self.hotplug_bus && self.contains(device) {
+ return Some(self.bus_num);
+ }
+ for (_, child_bus) in self.child_buses.iter() {
+ let hotplug_bus = child_bus.lock().get_hotplug_bus(device);
+ if hotplug_bus.is_some() {
+ return hotplug_bus;
+ }
+ }
+ return None;
}
}
diff --git a/devices/src/pci/pcie/pci_bridge.rs b/devices/src/pci/pcie/pci_bridge.rs
index e2021b0..33908ee 100644
--- a/devices/src/pci/pcie/pci_bridge.rs
+++ b/devices/src/pci/pcie/pci_bridge.rs
@@ -92,6 +92,7 @@
.lock()
.get_bus_range()
.expect("PciBridge's backend device must implement get_bus_range()");
+
let data = [
bus_range.primary,
bus_range.secondary,
@@ -99,15 +100,17 @@
0,
];
config.write_reg(BR_BUS_NUMBER_REG, 0, &data[..]);
+ let pci_bus = Arc::new(Mutex::new(PciBus::new(
+ bus_range.secondary,
+ bus_range.primary,
+ device.lock().hotplug_implemented(),
+ )));
PciBridge {
device,
config,
pci_address: None,
- pci_bus: Arc::new(Mutex::new(PciBus::new(
- bus_range.secondary,
- bus_range.primary,
- ))),
+ pci_bus,
bus_range,
msi_config,
msi_cap_offset,
