refactor: remove remaining usage of anyhow

The only place where anyhow was used is in the device manager
code that runs a specified function with a certain device. No instead
of converting the possible error of that function to anyhow::error,
just return the error and lest the call site do deal with it.

Signed-off-by: Egor Lazarchuk <yegorlz@amazon.co.uk>

Author: ShadowCurse

Cargo.lock

@@ -17,7 +17,6 @@ gdb = ["arrayvec", "gdbstub", "gdbstub_arch"]
 
 acpi_tables = { path = "../acpi-tables" }
 aes-gcm = { version = "0.10.1", default-features = false, features = ["aes"] }
-anyhow = "1.0.100"
 arrayvec = { version = "0.7.6", optional = true }
 aws-lc-rs = { version = "1.14.1", features = ["bindgen"] }
 base64 = "0.22.1"

src/vmm/Cargo.toml

@@ -91,8 +91,6 @@ pub enum FindDeviceError {
     InvalidDeviceType,
     /// Device not found
     DeviceNotFound,
-    /// Internal Device error: {0}
-    InternalDeviceError(anyhow::Error),
 }
 
 #[derive(Debug)]
@@ -376,19 +374,18 @@ impl DeviceManager {
         &self,
         id: &str,
         f: F,
-    ) -> Result<R, FindDeviceError>
+    ) -> Result<Result<R, E>, FindDeviceError>
     where
         T: VirtioDevice + 'static + Debug,
         E: std::error::Error + 'static + Send + Sync,
         F: FnOnce(&mut T) -> Result<R, E>,
     {
         if let Some(device) = self.get_virtio_device(T::const_device_type(), id) {
             let mut dev = device.lock().expect("Poisoned lock");
-            f(dev
+            Ok(f(dev
                 .as_mut_any()
                 .downcast_mut::<T>()
-                .ok_or(FindDeviceError::InvalidDeviceType)?)
-            .map_err(|e| FindDeviceError::InternalDeviceError(e.into()))
+                .ok_or(FindDeviceError::InvalidDeviceType)?))
         } else {
             Err(FindDeviceError::DeviceNotFound)
         }
@@ -400,7 +397,7 @@ impl DeviceManager {
         T: VirtioDevice + 'static + Debug,
         F: FnOnce(&mut T) -> R,
     {
-        self.try_with_virtio_device_with_id(id, |dev: &mut T| Ok::<R, FindDeviceError>(f(dev)))
+        self.try_with_virtio_device_with_id(id, |dev: &mut T| Ok::<R, FindDeviceError>(f(dev)))?
     }
 }
 

src/vmm/src/device_manager/mod.rs

@@ -136,7 +136,10 @@ use vstate::kvm::Kvm;
 use vstate::vcpu::{self, StartThreadedError, VcpuSendEventError};
 
 use crate::cpu_config::templates::CpuConfiguration;
-use crate::devices::virtio::balloon::{BALLOON_DEV_ID, Balloon, BalloonConfig, BalloonStats};
+use crate::devices::virtio::balloon::{
+    BALLOON_DEV_ID, Balloon, BalloonConfig, BalloonError, BalloonStats,
+};
+use crate::devices::virtio::block::BlockError;
 use crate::devices::virtio::block::device::Block;
 use crate::devices::virtio::net::Net;
 use crate::logger::{METRICS, MetricsError, error, info, warn};
@@ -248,6 +251,10 @@ pub enum VmmError {
     VMGenID(#[from] VmGenIdError),
     /// Failed perform action on device: {0}
     FindDeviceError(#[from] device_manager::FindDeviceError),
+    /// Block: {0}
+    Block(#[from] BlockError),
+    /// Balloon: {0}
+    Balloon(#[from] BalloonError),
 }
 
 /// Shorthand type for KVM dirty page bitmap.
@@ -522,7 +529,8 @@ impl Vmm {
             .try_with_virtio_device_with_id(drive_id, |block: &mut Block| {
                 block.update_disk_image(path_on_host)
             })
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(())
     }
 
     /// Updates the rate limiter parameters for block device with `drive_id` id.
@@ -536,14 +544,16 @@ impl Vmm {
             .try_with_virtio_device_with_id(drive_id, |block: &mut Block| {
                 block.update_rate_limiter(rl_bytes, rl_ops)
             })
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(())
     }
 
     /// Updates the rate limiter parameters for block device with `drive_id` id.
     pub fn update_vhost_user_block_config(&mut self, drive_id: &str) -> Result<(), VmmError> {
         self.device_manager
             .try_with_virtio_device_with_id(drive_id, |block: &mut Block| block.update_config())
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(())
     }
 
     /// Updates the rate limiter parameters for net device with `net_id` id.
@@ -571,9 +581,11 @@ impl Vmm {
 
     /// Returns the latest balloon statistics if they are enabled.
     pub fn latest_balloon_stats(&self) -> Result<BalloonStats, VmmError> {
-        self.device_manager
+        let stats = self
+            .device_manager
             .try_with_virtio_device_with_id(BALLOON_DEV_ID, |dev: &mut Balloon| dev.latest_stats())
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(stats)
     }
 
     /// Updates configuration for the balloon device target size.
@@ -582,7 +594,8 @@ impl Vmm {
             .try_with_virtio_device_with_id(BALLOON_DEV_ID, |dev: &mut Balloon| {
                 dev.update_size(amount_mib)
             })
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(())
     }
 
     /// Updates configuration for the balloon device as described in `balloon_stats_update`.
@@ -594,7 +607,8 @@ impl Vmm {
             .try_with_virtio_device_with_id(BALLOON_DEV_ID, |dev: &mut Balloon| {
                 dev.update_stats_polling_interval(stats_polling_interval_s)
             })
-            .map_err(VmmError::FindDeviceError)
+            .map_err(VmmError::FindDeviceError)??;
+        Ok(())
     }
 
     /// Signals Vmm to stop and exit.