arch: Use thiserror for errors

Added thiserror crate for missing files in the arch package

Signed-off-by: SamrutGadde <samrut.gadde@gmail.com>

arch/src/aarch64/fdt.rs

@@ -26,6 +26,7 @@ use super::layout::{
 };
 use std::fs;
 use std::path::Path;
+use thiserror::Error;
 use vm_fdt::{FdtWriter, FdtWriterResult};
 use vm_memory::{Address, Bytes, GuestMemory, GuestMemoryError, GuestMemoryRegion};
 
@@ -80,9 +81,10 @@ pub trait DeviceInfoForFdt {
 }
 
 /// Errors thrown while configuring the Flattened Device Tree for aarch64.
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum Error {
     /// Failure in writing FDT in memory.
+    #[error("Failure in writing FDT in memory: {0}")]
     WriteFdtToMemory(GuestMemoryError),
 }
 type Result<T> = result::Result<T, Error>;

arch/src/aarch64/mod.rs

@@ -18,32 +18,40 @@ use log::{log_enabled, Level};
 use std::collections::HashMap;
 use std::fmt::Debug;
 use std::sync::{Arc, Mutex};
+use thiserror::Error;
 use vm_memory::{Address, GuestAddress, GuestMemory, GuestMemoryAtomic};
 
 pub const _NSIG: i32 = 65;
 
 /// Errors thrown while configuring aarch64 system.
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum Error {
     /// Failed to create a FDT.
+    #[error("Failed to create a FDT")]
     SetupFdt,
 
     /// Failed to write FDT to memory.
+    #[error("Failed to write FDT to memory: {0}")]
     WriteFdtToMemory(fdt::Error),
 
     /// Failed to create a GIC.
+    #[error("Failed to create a GIC")]
     SetupGic,
 
     /// Failed to compute the initramfs address.
+    #[error("Failed to compute the initramfs address")]
     InitramfsAddress,
 
     /// Error configuring the general purpose registers
+    #[error("Error configuring the general purpose registers: {0}")]
     RegsConfiguration(hypervisor::HypervisorCpuError),
 
     /// Error configuring the MPIDR register
+    #[error("Error configuring the MPIDR register: {0}")]
     VcpuRegMpidr(hypervisor::HypervisorCpuError),
 
     /// Error initializing PMU for vcpu
+    #[error("Error initializing PMU for vcpu")]
     VcpuInitPmu,
 }
 

arch/src/aarch64/uefi.rs

@@ -5,18 +5,23 @@
 use std::io::{Read, Seek, SeekFrom};
 use std::os::fd::AsFd;
 use std::result;
+use thiserror::Error;
 use vm_memory::{GuestAddress, GuestMemory};
 
 /// Errors thrown while loading UEFI binary
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum Error {
     /// Unable to seek to UEFI image start.
+    #[error("Unable to seek to UEFI image start")]
     SeekUefiStart,
     /// Unable to seek to UEFI image end.
+    #[error("Unable to seek to UEFI image end")]
     SeekUefiEnd,
     /// UEFI image too big.
+    #[error("UEFI image too big")]
     UefiTooBig,
     /// Unable to read UEFI image
+    #[error("Unable to read UEFI image")]
     ReadUefiImage,
 }
 type Result<T> = result::Result<T, Error>;