Rework fw_cfg and add bootorder entry

devices/src/legacy/fw_cfg.rs

@@ -79,12 +79,27 @@ pub const PORT_FW_CFG_WIDTH: u64 = 0x10;
 
 const FW_CFG_SIGNATURE: u16 = 0x00;
 const FW_CFG_ID: u16 = 0x01;
+const FW_CFG_UUID: u16 = 0x02;
+const FW_CFG_RAM_SIZE: u16 = 0x03;
+const FW_CFG_NOGRAPHIC: u16 = 0x04;
+const FW_CFG_NB_CPUS: u16 = 0x05;
+const FW_CFG_MACHINE_ID: u16 = 0x06;
+const FW_CFG_KERNEL_ADDR: u16 = 0x07;
 const FW_CFG_KERNEL_SIZE: u16 = 0x08;
+const FW_CFG_KERNEL_CMDLINE: u16 = 0x09;
+const FW_CFG_INITRD_ADDR: u16 = 0x0a;
 const FW_CFG_INITRD_SIZE: u16 = 0x0b;
+const FW_CFG_BOOT_DEVICE: u16 = 0x0c;
+const FW_CFG_NUMA: u16 = 0x0d;
+const FW_CFG_BOOT_MENU: u16 = 0x0e;
+const FW_CFG_MAX_CPUS: u16 = 0x0f;
+const FW_CFG_KERNEL_ENTRY: u16 = 0x10;
 const FW_CFG_KERNEL_DATA: u16 = 0x11;
 const FW_CFG_INITRD_DATA: u16 = 0x12;
+const FW_CFG_CMDLINE_ADDR: u16 = 0x13;
 const FW_CFG_CMDLINE_SIZE: u16 = 0x14;
 const FW_CFG_CMDLINE_DATA: u16 = 0x15;
+const FW_CFG_SETUP_ADDR: u16 = 0x16;
 const FW_CFG_SETUP_SIZE: u16 = 0x17;
 const FW_CFG_SETUP_DATA: u16 = 0x18;
 const FW_CFG_FILE_DIR: u16 = 0x19;
@@ -116,7 +131,9 @@ pub enum FwCfgContent {
     Bytes(Vec<u8>),
     Slice(&'static [u8]),
     File(u64, File),
+    U64(u64),
     U32(u32),
+    U16(u16),
 }
 
 struct FwCfgContentAccess<'a> {
@@ -139,10 +156,18 @@ impl Read for FwCfgContentAccess<'_> {
                 Some(mut s) => s.read(buf),
                 None => Err(ErrorKind::UnexpectedEof)?,
             },
+            FwCfgContent::U64(n) => match n.to_le_bytes().get(self.offset as usize..) {
+                Some(mut s) => s.read(buf),
+                None => Err(ErrorKind::UnexpectedEof)?,
+            },
             FwCfgContent::U32(n) => match n.to_le_bytes().get(self.offset as usize..) {
                 Some(mut s) => s.read(buf),
                 None => Err(ErrorKind::UnexpectedEof)?,
             },
+            FwCfgContent::U16(n) => match n.to_le_bytes().get(self.offset as usize..) {
+                Some(mut s) => s.read(buf),
+                None => Err(ErrorKind::UnexpectedEof)?,
+            },
         }
     }
 }
@@ -159,7 +184,9 @@ impl FwCfgContent {
             FwCfgContent::Bytes(v) => v.len(),
             FwCfgContent::File(offset, f) => (f.metadata()?.len() - offset) as usize,
             FwCfgContent::Slice(s) => s.len(),
+            FwCfgContent::U64(n) => size_of_val(n),
             FwCfgContent::U32(n) => size_of_val(n),
+            FwCfgContent::U16(n) => size_of_val(n),
         };
         u32::try_from(ret).map_err(|_| std::io::ErrorKind::InvalidInput.into())
     }
@@ -419,10 +446,34 @@ impl FwCfg {
     pub fn new(memory: GuestMemoryAtomic<GuestMemoryMmap<AtomicBitmap>>) -> FwCfg {
         const DEFAULT_ITEM: FwCfgContent = FwCfgContent::Slice(&[]);
         let mut known_items = [DEFAULT_ITEM; FW_CFG_KNOWN_ITEMS];
+        let file_buf = Vec::from(FwCfgFilesHeader { count_be: 0 }.as_mut_bytes());
+
         known_items[FW_CFG_SIGNATURE as usize] = FwCfgContent::Slice(&FW_CFG_DMA_SIGNATURE);
         known_items[FW_CFG_ID as usize] = FwCfgContent::Slice(&FW_CFG_FEATURE);
-        let file_buf = Vec::from(FwCfgFilesHeader { count_be: 0 }.as_mut_bytes());
-        known_items[FW_CFG_FILE_DIR as usize] = FwCfgContent::Bytes(file_buf);
+        known_items[FW_CFG_UUID as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_RAM_SIZE as usize] = FwCfgContent::U64(0); /* TODO? */
+        known_items[FW_CFG_NOGRAPHIC as usize] = FwCfgContent::U16(0); /* TODO? */
+        known_items[FW_CFG_NB_CPUS as usize] = FwCfgContent::U16(0); /* TODO? */
+        known_items[FW_CFG_MACHINE_ID as usize] = FwCfgContent::U16(0); /* TODO? */
+        known_items[FW_CFG_KERNEL_ADDR as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_KERNEL_SIZE as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_KERNEL_CMDLINE as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_INITRD_ADDR as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_INITRD_SIZE as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_BOOT_DEVICE as usize] = FwCfgContent::U16(0); /* TODO? */
+        known_items[FW_CFG_NUMA as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_BOOT_MENU as usize] = FwCfgContent::U16(0); /* TODO? */
+        known_items[FW_CFG_MAX_CPUS as usize] = FwCfgContent::U16(255); /* TODO? */
+        known_items[FW_CFG_KERNEL_ENTRY as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_KERNEL_DATA as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_INITRD_DATA as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_CMDLINE_ADDR as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_CMDLINE_SIZE as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_CMDLINE_DATA as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_SETUP_ADDR as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_SETUP_SIZE as usize] = FwCfgContent::U32(0); /* TODO? */
+        known_items[FW_CFG_SETUP_DATA as usize] = FwCfgContent::Bytes(Default::default()); /* TODO? */
+        known_items[FW_CFG_FILE_DIR as usize] = FwCfgContent::Bytes(file_buf); /* TODO? */
 
         FwCfg {
             selector: 0,
@@ -737,10 +788,18 @@ impl FwCfg {
             FwCfgContent::File(o, f) => {
                 f.read_exact_at(data, o + offset as u64).ok()?;
             }
+            FwCfgContent::U64(n) => {
+                let bytes = n.to_le_bytes();
+                data.copy_from_slice(&bytes[start..end]);
+            }
             FwCfgContent::U32(n) => {
                 let bytes = n.to_le_bytes();
                 data.copy_from_slice(&bytes[start..end]);
             }
+            FwCfgContent::U16(n) => {
+                let bytes = n.to_le_bytes();
+                data.copy_from_slice(&bytes[start..end]);
+            }
         }
         Some(size as u8)
     }

vmm/src/config.rs

@@ -1370,6 +1370,7 @@ impl PciDeviceCommonConfig {
 }
 
 impl DiskConfig {
+    #[cfg(not(feature = "fw_cfg"))]
     pub const SYNTAX: &'static str = "Disk parameters \
          \"path=<disk_image_path>,readonly=on|off,direct=on|off,iommu=on|off,\
          num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,\
@@ -1382,6 +1383,20 @@ impl DiskConfig {
          serial=<serial_number>,backing_files=on|off,sparse=on|off,\
          image_type=<raw,qcow2,vhd,vhdx>,lock_granularity=byte-range|full";
 
+    #[cfg(feature = "fw_cfg")]
+    pub const SYNTAX: &'static str = "Disk parameters \
+         \"path=<disk_image_path>,readonly=on|off,direct=on|off,iommu=on|off,\
+         num_queues=<number_of_queues>,queue_size=<size_of_each_queue>,\
+         vhost_user=on|off,socket=<vhost_user_socket_path>,\
+         bw_size=<bytes>,bw_one_time_burst=<bytes>,bw_refill_time=<ms>,\
+         ops_size=<io_ops>,ops_one_time_burst=<io_ops>,ops_refill_time=<ms>,\
+         id=<device_id>,pci_segment=<segment_id>,pci_device_id=<pci_slot>,\
+         rate_limit_group=<group_id>,\
+         queue_affinity=<list_of_queue_indices_with_their_associated_cpuset>,\
+         serial=<serial_number>,backing_files=on|off,sparse=on|off,\
+         image_type=<raw,qcow2,vhd,vhdx>,lock_granularity=byte-range|full,\
+         bootindex=<index>";
+
     pub fn parse(disk: &str) -> Result<Self> {
         let mut parser = OptionParser::new();
         parser
@@ -1409,6 +1424,9 @@ impl DiskConfig {
             .add("lock_granularity")
             .add_all(PciDeviceCommonConfig::OPTIONS_IOMMU);
 
+        #[cfg(feature = "fw_cfg")]
+        parser.add("bootindex");
+
         parser.parse(disk).map_err(Error::ParseDisk)?;
 
         let path = parser.get("path").map(PathBuf::from);
@@ -1538,6 +1556,11 @@ impl DiskConfig {
 
         let pci_common = PciDeviceCommonConfig::parse(disk)?;
 
+        #[cfg(feature = "fw_cfg")]
+        let bootindex = parser
+            .convert::<u16>("bootindex")
+            .map_err(Error::ParseDisk)?;
+
         Ok(DiskConfig {
             pci_common,
             path,
@@ -1557,6 +1580,8 @@ impl DiskConfig {
             sparse,
             image_type,
             lock_granularity,
+            #[cfg(feature = "fw_cfg")]
+            bootindex,
         })
     }
 
@@ -4125,6 +4150,8 @@ mod unit_tests {
             sparse: true,
             image_type: ImageType::Unknown,
             lock_granularity: LockGranularityChoice::default(),
+            #[cfg(feature = "fw_cfg")]
+            bootindex: Default::default(),
         }
     }
 

vmm/src/device_manager.rs

@@ -119,6 +119,8 @@ use crate::interrupt::{LegacyUserspaceInterruptManager, MsiInterruptManager};
 use crate::memory_manager::{Error as MemoryManagerError, MEMORY_MANAGER_ACPI_SIZE, MemoryManager};
 use crate::pci_segment::PciSegment;
 use crate::serial_manager::{Error as SerialManagerError, SerialManager};
+#[cfg(feature = "fw_cfg")]
+use crate::vm_config::FwCfgConfig;
 #[cfg(feature = "ivshmem")]
 use crate::vm_config::IvshmemConfig;
 use crate::vm_config::{
@@ -1149,6 +1151,9 @@ pub struct DeviceManager {
     #[cfg(feature = "ivshmem")]
     // ivshmem device
     ivshmem_device: Option<Arc<Mutex<devices::IvshmemDevice>>>,
+
+    #[cfg(feature = "fw_cfg")]
+    boot_order: HashMap<u16, String>,
 }
 
 /// Create per-PCI-segment MMIO allocators over the range `[start, end]`.
@@ -1439,6 +1444,8 @@ impl DeviceManager {
             #[cfg(feature = "ivshmem")]
             ivshmem_device: None,
             _acpi_cpu_hotplug_controller: acpi_cpu_hotplug_controller,
+            #[cfg(feature = "fw_cfg")]
+            boot_order: HashMap::new(),
         };
 
         let device_manager = Arc::new(Mutex::new(device_manager));
@@ -1565,6 +1572,18 @@ impl DeviceManager {
             self.ivshmem_device = self.add_ivshmem_device(ivshmem, snapshot)?;
         }
 
+        #[cfg(feature = "fw_cfg")]
+        {
+            // if we have a boot order but no fw_cfg device, we must create on
+            let mut vm_config = self.config.lock().unwrap();
+            if !self.boot_order.is_empty()
+                && vm_config.payload.is_some()
+                && vm_config.payload.as_mut().unwrap().fw_cfg_config.is_none()
+            {
+                vm_config.payload.as_mut().unwrap().fw_cfg_config = Some(FwCfgConfig::default());
+            }
+        }
+
         Ok(())
     }
 
@@ -2895,6 +2914,11 @@ impl DeviceManager {
             .unwrap()
             .insert(id.clone(), device_node!(id, migratable_device));
 
+        #[cfg(feature = "fw_cfg")]
+        if let Some(bootindex) = disk_cfg.bootindex {
+            self.boot_order.insert(bootindex, id.clone());
+        }
+
         Ok(MetaVirtioDevice {
             virtio_device,
             pci_common: disk_cfg.pci_common.clone(),
@@ -4403,11 +4427,31 @@ impl DeviceManager {
         }
 
         // Update the device tree with correct resource information.
+        #[cfg(feature = "fw_cfg")]
+        let node_id = node.id.clone();
+
         node.resources = new_resources;
         node.migratable = Some(Arc::clone(&virtio_pci_device) as Arc<Mutex<dyn Migratable>>);
         node.pci_bdf = Some(pci_device_bdf);
         node.pci_device_handle = Some(PciDeviceHandle::Virtio(virtio_pci_device));
-        self.device_tree.lock().unwrap().insert(id, node);
+        self.device_tree.lock().unwrap().insert(id.clone(), node);
+
+        #[cfg(feature = "fw_cfg")]
+        {
+            // Find the virtio device in the boot item list
+            let boot_entry = self
+                .boot_order
+                .iter()
+                .find(|(_k, v)| *v == virtio_device_id);
+
+            // Update the device ID in the boot item list
+            if let Some((k, _)) = boot_entry {
+                self.boot_order.insert(
+                    *k,
+                    self.device_tree.lock().unwrap().fw_cfg_path_by_id(&node_id),
+                );
+            }
+        }
 
         Ok(pci_device_bdf)
     }
@@ -5319,7 +5363,6 @@ impl DeviceManager {
             self.vfio_ops = None;
         }
     }
-
     /// Helps the environment converge quickly after a live migration by
     /// prompting devices to advertise the VM from its new host.
     ///
@@ -5362,6 +5405,19 @@ impl DeviceManager {
             MAX_DELAY,
         );
     }
+
+    /// Returns a list of devices to boot from in the order expected
+    #[cfg(feature = "fw_cfg")]
+    pub fn get_bootitems(&self) -> Vec<String> {
+        let mut result: Vec<String> = Vec::new();
+        let mut keys: Vec<u16> = self.boot_order.clone().into_keys().collect();
+        keys.sort();
+
+        for k in &keys {
+            result.push(self.boot_order.get(k).unwrap().clone());
+        }
+        result
+    }
 }
 
 /// Starts a thread that periodically performs the post-migration announcements.

vmm/src/device_tree.rs

@@ -7,11 +7,27 @@ use std::sync::{Arc, Mutex};
 
 use pci::PciBdf;
 use serde::{Deserialize, Serialize};
+#[cfg(feature = "fw_cfg")]
+use thiserror::Error;
 use vm_device::Resource;
 use vm_migration::Migratable;
 
 use crate::device_manager::PciDeviceHandle;
 
+#[cfg(feature = "fw_cfg")]
+#[derive(Debug, Error)]
+pub enum DeviceNodePathError {
+    /// Device is not attached to a bus.
+    #[error("Can't create a open firmware device path from a device not attached to a bus")]
+    NoBusDevice,
+    /// Device is not bootable.
+    #[error("Can't create a open firmware device path for a non-bootable device")]
+    DeviceNotBootable,
+    /// Device is not a PCI device.
+    #[error("Currently only PCI devices are supported!")]
+    NoPciDevice,
+}
+
 #[derive(Clone, Serialize, Deserialize)]
 pub struct DeviceNode {
     pub id: String,
@@ -37,6 +53,36 @@ impl DeviceNode {
             pci_device_handle: None,
         }
     }
+
+    /// Returns the open firmware device path
+    ///
+    /// The open firmware path is used by Qemu in it's `fw_cfg` device to pass boot order hints
+    /// to EDK2/OVMF. [0]
+    ///
+    /// [0] https://github.com/tianocore/edk2/blob/2816ff0ab0d6505bf580aa8eec02cc2b89f04230/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c#L1222
+    #[cfg(feature = "fw_cfg")]
+    pub fn openfw_device_path(&self) -> Result<String, DeviceNodePathError> {
+        if let Some(handle) = &self.pci_device_handle {
+            if let PciDeviceHandle::Virtio(virtio_handle) = handle {
+                let virtio_device = virtio_handle.lock().unwrap();
+                let device_type = virtio_device.virtio_device().lock().unwrap().device_type();
+                if let Some(bdf) = self.pci_bdf {
+                    match device_type {
+                        0x2 /* VirtioBlk */ => {
+                            Ok(format!("/pci@i0cf8/scsi@{:x}/disk@0,0", bdf.device()))
+                        }
+                        _ => Err(DeviceNodePathError::DeviceNotBootable),
+                    }
+                } else {
+                    unreachable!("PCI devices should have a bdf!")
+                }
+            } else {
+                Err(DeviceNodePathError::NoPciDevice)
+            }
+        } else {
+            Err(DeviceNodePathError::NoBusDevice)
+        }
+    }
 }
 
 #[macro_export]
@@ -102,6 +148,11 @@ impl DeviceTree {
             None
         }
     }
+
+    #[cfg(feature = "fw_cfg")]
+    pub fn fw_cfg_path_by_id(&self, id: &str) -> String {
+        self.get(id).unwrap().openfw_device_path().unwrap()
+    }
 }
 
 // Breadth first traversal iterator.