Change interrupt_status to u32

Interrupt statuses are stored as 32-bit values in the system, but as
64-bit values in the snapshots. This commit changes the snapshot type to
a u32 to remove those conversions.

Signed-off-by: Jonathan Browne <[email protected]>

Author: JBYoshi

src/vmm/src/device_manager/mmio.rs

@@ -462,7 +462,7 @@ impl DeviceInfoForFDT for MMIODeviceInfo {
 
 #[cfg(test)]
 mod tests {
-    use std::sync::atomic::AtomicUsize;
+    use std::sync::atomic::AtomicU32;
     use std::sync::Arc;
 
     use utils::eventfd::EventFd;
@@ -541,8 +541,8 @@ mod tests {
             &self.interrupt_evt
         }
 
-        fn interrupt_status(&self) -> Arc<AtomicUsize> {
-            Arc::new(AtomicUsize::new(0))
+        fn interrupt_status(&self) -> Arc<AtomicU32> {
+            Arc::new(AtomicU32::new(0))
         }
 
         fn ack_features_by_page(&mut self, page: u32, value: u32) {

src/vmm/src/devices/virtio/balloon/device.rs

@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 use std::io::Write;
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::Arc;
 use std::time::Duration;
 use std::{cmp, fmt};
@@ -586,7 +586,7 @@ impl VirtioDevice for Balloon {
         &self.irq_trigger.irq_evt
     }
 
-    fn interrupt_status(&self) -> Arc<AtomicUsize> {
+    fn interrupt_status(&self) -> Arc<AtomicU32> {
         self.irq_trigger.irq_status.clone()
     }
 

src/vmm/src/devices/virtio/balloon/persist.rs

@@ -3,7 +3,7 @@
 
 //! Defines the structures needed for saving/restoring balloon devices.
 
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::Arc;
 use std::time::Duration;
 
@@ -141,7 +141,7 @@ impl Persist<'_> for Balloon {
             )
             .map_err(|_| Self::Error::QueueRestoreError)?;
         balloon.irq_trigger.irq_status =
-            Arc::new(AtomicUsize::new(state.virtio_state.interrupt_status));
+            Arc::new(AtomicU32::new(state.virtio_state.interrupt_status));
         balloon.avail_features = state.virtio_state.avail_features;
         balloon.acked_features = state.virtio_state.acked_features;
         balloon.latest_stats = state.latest_stats.create_stats();

src/vmm/src/devices/virtio/block/device.rs

@@ -11,7 +11,7 @@ use std::fs::{File, OpenOptions};
 use std::io::{Seek, SeekFrom, Write};
 use std::os::linux::fs::MetadataExt;
 use std::path::PathBuf;
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::Arc;
 
 use block_io::FileEngine;
@@ -571,7 +571,7 @@ impl VirtioDevice for Block {
     }
 
     /// Returns the current device interrupt status.
-    fn interrupt_status(&self) -> Arc<AtomicUsize> {
+    fn interrupt_status(&self) -> Arc<AtomicU32> {
         self.irq_trigger.irq_status.clone()
     }
 

src/vmm/src/devices/virtio/block/persist.rs

@@ -3,7 +3,7 @@
 
 //! Defines the structures needed for saving/restoring block devices.
 
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::Arc;
 
 use snapshot::Persist;
@@ -201,7 +201,7 @@ impl Persist<'_> for Block {
             )
             .map_err(BlockError::Persist)?;
         block.irq_trigger.irq_status =
-            Arc::new(AtomicUsize::new(state.virtio_state.interrupt_status));
+            Arc::new(AtomicU32::new(state.virtio_state.interrupt_status));
         block.avail_features = state.virtio_state.avail_features;
         block.acked_features = state.virtio_state.acked_features;
 

src/vmm/src/devices/virtio/device.rs

@@ -6,7 +6,7 @@
 // found in the THIRD-PARTY file.
 
 use std::fmt;
-use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 
 use utils::eventfd::EventFd;
@@ -54,14 +54,14 @@ pub enum IrqType {
 /// Helper struct that is responsible for triggering guest IRQs
 #[derive(Debug)]
 pub struct IrqTrigger {
-    pub(crate) irq_status: Arc<AtomicUsize>,
+    pub(crate) irq_status: Arc<AtomicU32>,
     pub(crate) irq_evt: EventFd,
 }
 
 impl IrqTrigger {
     pub fn new() -> std::io::Result<Self> {
         Ok(Self {
-            irq_status: Arc::new(AtomicUsize::new(0)),
+            irq_status: Arc::new(AtomicU32::new(0)),
             irq_evt: EventFd::new(libc::EFD_NONBLOCK)?,
         })
     }
@@ -71,7 +71,7 @@ impl IrqTrigger {
             IrqType::Config => VIRTIO_MMIO_INT_CONFIG,
             IrqType::Vring => VIRTIO_MMIO_INT_VRING,
         };
-        self.irq_status.fetch_or(irq as usize, Ordering::SeqCst);
+        self.irq_status.fetch_or(irq, Ordering::SeqCst);
 
         self.irq_evt.write(1).map_err(|err| {
             error!("Failed to send irq to the guest: {:?}", err);
@@ -121,7 +121,7 @@ pub trait VirtioDevice: AsAny + Send {
     fn interrupt_evt(&self) -> &EventFd;
 
     /// Returns the current device interrupt status.
-    fn interrupt_status(&self) -> Arc<AtomicUsize>;
+    fn interrupt_status(&self) -> Arc<AtomicU32>;
 
     /// The set of feature bits shifted by `page * 32`.
     fn avail_features_by_page(&self, page: u32) -> u32 {
@@ -196,7 +196,7 @@ pub(crate) mod tests {
                     return false;
                 }
 
-                let irq_status = self.irq_status.load(Ordering::SeqCst) as u32;
+                let irq_status = self.irq_status.load(Ordering::SeqCst);
                 return matches!(
                     (irq_status, irq_type),
                     (VIRTIO_MMIO_INT_CONFIG, IrqType::Config)
@@ -268,7 +268,7 @@ pub(crate) mod tests {
             todo!()
         }
 
-        fn interrupt_status(&self) -> Arc<AtomicUsize> {
+        fn interrupt_status(&self) -> Arc<AtomicU32> {
             todo!()
         }
 

src/vmm/src/devices/virtio/mmio.rs

@@ -6,7 +6,7 @@
 // found in the THIRD-PARTY file.
 
 use std::fmt::Debug;
-use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::{Arc, Mutex, MutexGuard};
 
 use utils::byte_order;
@@ -54,7 +54,7 @@ pub struct MmioTransport {
     pub(crate) device_status: u32,
     pub(crate) config_generation: u32,
     mem: GuestMemoryMmap,
-    pub(crate) interrupt_status: Arc<AtomicUsize>,
+    pub(crate) interrupt_status: Arc<AtomicU32>,
 }
 
 impl MmioTransport {
@@ -237,7 +237,7 @@ impl MmioTransport {
                     }
                     0x34 => self.with_queue(0, |q| u32::from(q.get_max_size())),
                     0x44 => self.with_queue(0, |q| u32::from(q.ready)),
-                    0x60 => self.interrupt_status.load(Ordering::SeqCst) as u32,
+                    0x60 => self.interrupt_status.load(Ordering::SeqCst),
                     0x70 => self.device_status,
                     0xfc => self.config_generation,
                     _ => {
@@ -292,8 +292,7 @@ impl MmioTransport {
                     0x44 => self.update_queue_field(|q| q.ready = v == 1),
                     0x64 => {
                         if self.check_device_status(device_status::DRIVER_OK, 0) {
-                            self.interrupt_status
-                                .fetch_and(!(v as usize), Ordering::SeqCst);
+                            self.interrupt_status.fetch_and(!v, Ordering::SeqCst);
                         }
                     }
                     0x70 => self.set_device_status(v),
@@ -340,7 +339,7 @@ pub(crate) mod tests {
         acked_features: u64,
         avail_features: u64,
         interrupt_evt: EventFd,
-        interrupt_status: Arc<AtomicUsize>,
+        interrupt_status: Arc<AtomicU32>,
         queue_evts: Vec<EventFd>,
         queues: Vec<Queue>,
         device_activated: bool,
@@ -353,7 +352,7 @@ pub(crate) mod tests {
                 acked_features: 0,
                 avail_features: 0,
                 interrupt_evt: EventFd::new(libc::EFD_NONBLOCK).unwrap(),
-                interrupt_status: Arc::new(AtomicUsize::new(0)),
+                interrupt_status: Arc::new(AtomicU32::new(0)),
                 queue_evts: vec![
                     EventFd::new(libc::EFD_NONBLOCK).unwrap(),
                     EventFd::new(libc::EFD_NONBLOCK).unwrap(),
@@ -402,7 +401,7 @@ pub(crate) mod tests {
             &self.interrupt_evt
         }
 
-        fn interrupt_status(&self) -> Arc<AtomicUsize> {
+        fn interrupt_status(&self) -> Arc<AtomicU32> {
             self.interrupt_status.clone()
         }
 

src/vmm/src/devices/virtio/net/device.rs

@@ -7,7 +7,7 @@
 
 use std::io::{Read, Write};
 use std::net::Ipv4Addr;
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::{Arc, Mutex};
 use std::{cmp, mem};
 
@@ -789,7 +789,7 @@ impl VirtioDevice for Net {
         &self.irq_trigger.irq_evt
     }
 
-    fn interrupt_status(&self) -> Arc<AtomicUsize> {
+    fn interrupt_status(&self) -> Arc<AtomicU32> {
         self.irq_trigger.irq_status.clone()
     }
 

src/vmm/src/devices/virtio/net/persist.rs

@@ -4,7 +4,7 @@
 //! Defines the structures needed for saving/restoring net devices.
 
 use std::io;
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::AtomicU32;
 use std::sync::{Arc, Mutex};
 
 use log::warn;
@@ -156,8 +156,7 @@ impl Persist<'_> for Net {
             NET_NUM_QUEUES,
             FIRECRACKER_MAX_QUEUE_SIZE,
         )?;
-        net.irq_trigger.irq_status =
-            Arc::new(AtomicUsize::new(state.virtio_state.interrupt_status));
+        net.irq_trigger.irq_status = Arc::new(AtomicU32::new(state.virtio_state.interrupt_status));
         net.avail_features = state.virtio_state.avail_features;
         net.acked_features = state.virtio_state.acked_features;
 

src/vmm/src/devices/virtio/persist.rs

@@ -103,7 +103,15 @@ pub struct VirtioDeviceState {
     /// List of queues.
     pub queues: Vec<QueueState>,
     /// The MMIO interrupt status.
-    pub interrupt_status: usize,
+    #[version(
+        start = 2,
+        de_fn = "de_interrupt_status",
+        ser_fn = "ser_interrupt_status"
+    )]
+    pub interrupt_status: u32,
+    /// The MMIO interrupt status as a usize.
+    #[version(end = 2)]
+    pub interrupt_status_old: usize,
     /// Flag for activated status.
     pub activated: bool,
 }
@@ -117,6 +125,7 @@ impl VirtioDeviceState {
             acked_features: device.acked_features(),
             queues: device.queues().iter().map(Persist::save).collect(),
             interrupt_status: device.interrupt_status().load(Ordering::Relaxed),
+            interrupt_status_old: device.interrupt_status().load(Ordering::Relaxed) as usize,
             activated: device.is_activated(),
         }
     }
@@ -170,6 +179,21 @@ impl VirtioDeviceState {
         }
         Ok(queues)
     }
+
+    #[allow(clippy::cast_possible_truncation)]
+    fn de_interrupt_status(&mut self, version: u16) -> VersionizeResult<()> {
+        // v1 uses a usize type for interrupt status.
+        if version < 2 {
+            self.interrupt_status = self.interrupt_status_old as u32;
+        }
+        Ok(())
+    }
+
+    fn ser_interrupt_status(&mut self, _target_version: u16) -> VersionizeResult<()> {
+        // v1 uses a usize type for interrupt status.
+        self.interrupt_status_old = self.interrupt_status as usize;
+        Ok(())
+    }
 }
 
 /// Transport information saved in snapshot.