Platform dependent irq assignment for the mmio device manager

arch/src/aarch64/layout.rs

@@ -5,3 +5,15 @@
 pub const CMDLINE_START: usize = 0x0;
 /// Kernel command line start address maximum size.
 pub const CMDLINE_MAX_SIZE: usize = 0x0;
+
+// As per virt/kvm/arm/vgic/vgic-kvm-device.c we need
+// the number of interrupts our GIC will support to be:
+// * bigger than 32
+// * less than 1023 and
+// * a multiple of 32.
+// We are setting up our interrupt controller to support a maximum of 128 interrupts.
+/// First usable interrupt on aarch64.
+pub const IRQ_BASE: u32 = 32;
+
+/// Last usable interrupt on aarch64.
+pub const IRQ_MAX: u32 = 159;

arch/src/lib.rs

@@ -28,7 +28,7 @@ pub mod aarch64;
 #[cfg(target_arch = "aarch64")]
 pub use aarch64::{
     arch_memory_regions, configure_system, get_reserved_mem_addr, layout::CMDLINE_MAX_SIZE,
-    layout::CMDLINE_START,
+    layout::CMDLINE_START, layout::IRQ_BASE, layout::IRQ_MAX,
 };
 
 #[cfg(target_arch = "x86_64")]
@@ -37,5 +37,5 @@ pub mod x86_64;
 #[cfg(target_arch = "x86_64")]
 pub use x86_64::{
     arch_memory_regions, configure_system, get_32bit_gap_start as get_reserved_mem_addr,
-    layout::CMDLINE_MAX_SIZE, layout::CMDLINE_START,
+    layout::CMDLINE_MAX_SIZE, layout::CMDLINE_START, layout::IRQ_BASE, layout::IRQ_MAX,
 };

arch/src/x86_64/layout.rs

@@ -16,6 +16,12 @@ pub const CMDLINE_START: usize = 0x20000;
 /// Kernel command line start address maximum size.
 pub const CMDLINE_MAX_SIZE: usize = 0x10000;
 
+// Typically, on x86 systems 16 IRQs are used (0-15).
+/// First usable IRQ ID for virtio device interrupts on x86_64.
+pub const IRQ_BASE: u32 = 5;
+/// Last usable IRQ ID for virtio device interrupts on x86_64.
+pub const IRQ_MAX: u32 = 15;
+
 /// Address for the TSS setup.
 pub const KVM_TSS_ADDRESS: usize = 0xfffb_d000;
 

vmm/src/device_manager/mmio.rs

@@ -53,11 +53,6 @@ impl fmt::Display for Error {
 
 type Result<T> = ::std::result::Result<T, Error>;
 
-/// Typically, on x86 systems 16 IRQs are used (0-15)
-/// Our device manager uses the IRQs from 5 to 16
-const MAX_IRQ: u32 = 15;
-const IRQ_BASE: u32 = 5;
-
 /// This represents the size of the mmio device specified to the kernel as a cmdline option
 /// It has to be larger than 0x100 (the offset where the configuration space starts from
 /// the beginning of the memory mapped device registers) + the size of the configuration space
@@ -75,17 +70,23 @@ pub struct MMIODeviceManager {
     guest_mem: GuestMemory,
     mmio_base: u64,
     irq: u32,
+    last_irq: u32,
     id_to_addr_map: HashMap<String, u64>,
 }
 
 impl MMIODeviceManager {
     /// Create a new DeviceManager handling mmio devices (virtio net, block).
-    pub fn new(guest_mem: GuestMemory, mmio_base: u64) -> MMIODeviceManager {
+    pub fn new(
+        guest_mem: GuestMemory,
+        mmio_base: u64,
+        irq_interval: (u32, u32),
+    ) -> MMIODeviceManager {
         MMIODeviceManager {
             guest_mem,
             vm_requests: Vec::new(),
             mmio_base,
-            irq: IRQ_BASE,
+            irq: irq_interval.0,
+            last_irq: irq_interval.1,
             bus: devices::Bus::new(),
             id_to_addr_map: HashMap::new(),
         }
@@ -98,7 +99,7 @@ impl MMIODeviceManager {
         cmdline: &mut kernel_cmdline::Cmdline,
         id: Option<String>,
     ) -> Result<u64> {
-        if self.irq > MAX_IRQ {
+        if self.irq > self.last_irq {
             return Err(Error::IrqsExhausted);
         }
 
@@ -180,6 +181,7 @@ impl MMIODeviceManager {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use arch;
     use devices::virtio::{ActivateResult, VirtioDevice};
     use kernel_cmdline;
     use memory_model::{GuestAddress, GuestMemory};
@@ -236,7 +238,8 @@ mod tests {
         let start_addr1 = GuestAddress(0x0);
         let start_addr2 = GuestAddress(0x1000);
         let guest_mem = GuestMemory::new(&[(start_addr1, 0x1000), (start_addr2, 0x1000)]).unwrap();
-        let mut device_manager = MMIODeviceManager::new(guest_mem, 0xd000_0000);
+        let mut device_manager =
+            MMIODeviceManager::new(guest_mem, 0xd000_0000, (arch::IRQ_BASE, arch::IRQ_MAX));
 
         let mut cmdline = kernel_cmdline::Cmdline::new(4096);
         let dummy_box = Box::new(DummyDevice { dummy: 0 });
@@ -251,11 +254,12 @@ mod tests {
         let start_addr1 = GuestAddress(0x0);
         let start_addr2 = GuestAddress(0x1000);
         let guest_mem = GuestMemory::new(&[(start_addr1, 0x1000), (start_addr2, 0x1000)]).unwrap();
-        let mut device_manager = MMIODeviceManager::new(guest_mem, 0xd000_0000);
+        let mut device_manager =
+            MMIODeviceManager::new(guest_mem, 0xd000_0000, (arch::IRQ_BASE, arch::IRQ_MAX));
 
         let mut cmdline = kernel_cmdline::Cmdline::new(4096);
         let dummy_box = Box::new(DummyDevice { dummy: 0 });
-        for _i in IRQ_BASE..=MAX_IRQ {
+        for _i in arch::IRQ_BASE..=arch::IRQ_MAX {
             device_manager
                 .register_device(dummy_box.clone(), &mut cmdline, None)
                 .unwrap();
@@ -291,7 +295,8 @@ mod tests {
         let start_addr1 = GuestAddress(0x0);
         let start_addr2 = GuestAddress(0x1000);
         let guest_mem = GuestMemory::new(&[(start_addr1, 0x1000), (start_addr2, 0x1000)]).unwrap();
-        let device_manager = MMIODeviceManager::new(guest_mem, 0xd000_0000);
+        let device_manager =
+            MMIODeviceManager::new(guest_mem, 0xd000_0000, (arch::IRQ_BASE, arch::IRQ_MAX));
         let mut cmdline = kernel_cmdline::Cmdline::new(4096);
         let e = Error::Cmdline(
             cmdline
@@ -332,7 +337,8 @@ mod tests {
         let start_addr1 = GuestAddress(0x0);
         let start_addr2 = GuestAddress(0x1000);
         let guest_mem = GuestMemory::new(&[(start_addr1, 0x1000), (start_addr2, 0x1000)]).unwrap();
-        let mut device_manager = MMIODeviceManager::new(guest_mem, 0xd000_0000);
+        let mut device_manager =
+            MMIODeviceManager::new(guest_mem, 0xd000_0000, (arch::IRQ_BASE, arch::IRQ_MAX));
         let mut cmdline = kernel_cmdline::Cmdline::new(4096);
         let dummy_box = Box::new(DummyDevice { dummy: 0 });
 
@@ -349,7 +355,8 @@ mod tests {
         let start_addr1 = GuestAddress(0x0);
         let start_addr2 = GuestAddress(0x1000);
         let guest_mem = GuestMemory::new(&[(start_addr1, 0x1000), (start_addr2, 0x1000)]).unwrap();
-        let mut device_manager = MMIODeviceManager::new(guest_mem, 0xd000_0000);
+        let mut device_manager =
+            MMIODeviceManager::new(guest_mem, 0xd000_0000, (arch::IRQ_BASE, arch::IRQ_MAX));
         let mut cmdline = kernel_cmdline::Cmdline::new(4096);
         let dummy_box = Box::new(DummyDevice { dummy: 0 });
 

vmm/src/lib.rs

@@ -927,8 +927,11 @@ impl Vmm {
 
         // Instantiate the MMIO device manager.
         // 'mmio_base' address has to be an address which is protected by the kernel.
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
 
         self.attach_block_devices(&mut device_manager)?;
         self.attach_net_devices(&mut device_manager)?;
@@ -2372,8 +2375,11 @@ mod tests {
         vmm.init_guest_memory().unwrap();
         vmm.default_kernel_config();
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
         vmm.attach_net_devices(&mut device_manager).unwrap();
         vmm.set_instance_state(InstanceState::Running);
 
@@ -2648,8 +2654,11 @@ mod tests {
         vmm.default_kernel_config();
 
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
         assert!(vmm.attach_block_devices(&mut device_manager).is_ok());
         assert!(vmm.get_kernel_cmdline_str().contains("root=/dev/vda"));
 
@@ -2672,8 +2681,11 @@ mod tests {
         vmm.default_kernel_config();
 
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
         assert!(vmm.attach_block_devices(&mut device_manager).is_ok());
         assert!(vmm
             .get_kernel_cmdline_str()
@@ -2700,8 +2712,11 @@ mod tests {
         vmm.default_kernel_config();
 
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
         assert!(vmm.attach_block_devices(&mut device_manager).is_ok());
         // Test that kernel commandline does not contain either /dev/vda or PARTUUID.
         assert!(!vmm.get_kernel_cmdline_str().contains("root=PARTUUID="));
@@ -2734,8 +2749,11 @@ mod tests {
         vmm.default_kernel_config();
 
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
 
         // test create network interface
         let network_interface = NetworkInterfaceConfig {
@@ -2830,8 +2848,11 @@ mod tests {
         assert!(vmm.guest_memory.is_some());
 
         let guest_mem = vmm.guest_memory.clone().unwrap();
-        let mut device_manager =
-            MMIODeviceManager::new(guest_mem.clone(), arch::get_reserved_mem_addr() as u64);
+        let mut device_manager = MMIODeviceManager::new(
+            guest_mem.clone(),
+            arch::get_reserved_mem_addr() as u64,
+            (arch::IRQ_BASE, arch::IRQ_MAX),
+        );
 
         let dummy_box = Box::new(DummyDevice { dummy: 0 });
         // Use a dummy command line as it is not used in this test.