misc: Adapt consistent import style formatting

Historically the Cloud Hypervisor coding style has been to ensure that
all imports are ordered and placed in a single group. Unfortunately
cargo fmt has no support for ensuring that all imports are in a single
group so if whitespace lines were added as part of the import statements
then they would only be odered correctly in the group.

By adopting "group_imports="StdExternalCrate" we can enforce a style
where imports are placed in at most three groups for std, external
crates and the crate itself. Choosing a style enforceable by the tooling
reduces the reviewer burden.

Signed-off-by: Rob Bradford <rbradford@rivosinc.com>

hypervisor/src/mshv/mod.rs

@@ -3,6 +3,15 @@
 // Copyright © 2020, Microsoft Corporation
 //
 
+use std::any::Any;
+use std::collections::HashMap;
+use std::sync::{Arc, RwLock};
+
+use mshv_bindings::*;
+use mshv_ioctls::{set_registers_64, InterruptRequest, Mshv, NoDatamatch, VcpuFd, VmFd, VmType};
+use vfio_ioctls::VfioDeviceFd;
+use vm::DataMatch;
+
 use crate::arch::emulator::PlatformEmulator;
 #[cfg(target_arch = "x86_64")]
 use crate::arch::x86::emulator::Emulator;
@@ -12,18 +21,32 @@ use crate::mshv::emulator::MshvEmulatorContext;
 use crate::vec_with_array_field;
 use crate::vm::{self, InterruptSourceConfig, VmOps};
 use crate::HypervisorType;
-use mshv_bindings::*;
-use mshv_ioctls::{set_registers_64, InterruptRequest, Mshv, NoDatamatch, VcpuFd, VmFd, VmType};
-use std::any::Any;
-use std::collections::HashMap;
-use std::sync::{Arc, RwLock};
-use vfio_ioctls::VfioDeviceFd;
-use vm::DataMatch;
 #[cfg(feature = "sev_snp")]
 mod snp_constants;
 // x86_64 dependencies
 #[cfg(target_arch = "x86_64")]
 pub mod x86_64;
+#[cfg(target_arch = "x86_64")]
+use std::fs::File;
+use std::os::unix::io::AsRawFd;
+
+#[cfg(feature = "sev_snp")]
+use igvm_defs::IGVM_VHS_SNP_ID_BLOCK;
+#[cfg(feature = "sev_snp")]
+use snp_constants::*;
+use vmm_sys_util::eventfd::EventFd;
+#[cfg(target_arch = "x86_64")]
+pub use x86_64::*;
+#[cfg(target_arch = "x86_64")]
+pub use x86_64::{emulator, VcpuMshvState};
+///
+/// Export generically-named wrappers of mshv-bindings for Unix-based platforms
+///
+pub use {
+    mshv_bindings::mshv_create_device as CreateDevice,
+    mshv_bindings::mshv_device_attr as DeviceAttr, mshv_ioctls, mshv_ioctls::DeviceFd,
+};
+
 #[cfg(target_arch = "x86_64")]
 use crate::arch::x86::{CpuIdEntry, FpuState, MsrEntry};
 #[cfg(target_arch = "x86_64")]
@@ -33,26 +56,6 @@ use crate::{
     USER_MEMORY_REGION_ADJUSTABLE, USER_MEMORY_REGION_EXECUTE, USER_MEMORY_REGION_READ,
     USER_MEMORY_REGION_WRITE,
 };
-#[cfg(feature = "sev_snp")]
-use igvm_defs::IGVM_VHS_SNP_ID_BLOCK;
-#[cfg(feature = "sev_snp")]
-use snp_constants::*;
-#[cfg(target_arch = "x86_64")]
-use std::fs::File;
-use std::os::unix::io::AsRawFd;
-use vmm_sys_util::eventfd::EventFd;
-#[cfg(target_arch = "x86_64")]
-pub use x86_64::*;
-#[cfg(target_arch = "x86_64")]
-pub use x86_64::{emulator, VcpuMshvState};
-
-///
-/// Export generically-named wrappers of mshv-bindings for Unix-based platforms
-///
-pub use {
-    mshv_bindings::mshv_create_device as CreateDevice,
-    mshv_bindings::mshv_device_attr as DeviceAttr, mshv_ioctls, mshv_ioctls::DeviceFd,
-};
 
 pub const PAGE_SHIFT: usize = 12;
 

hypervisor/src/mshv/x86_64/emulator.rs

@@ -3,12 +3,13 @@
 // Copyright © 2024, Microsoft Corporation
 //
 
+use iced_x86::Register;
+use mshv_bindings::*;
+
 use crate::arch::emulator::{PlatformEmulator, PlatformError};
 use crate::arch::x86::emulator::{CpuStateManager, EmulatorCpuState};
 use crate::cpu::Vcpu;
 use crate::mshv::MshvVcpu;
-use iced_x86::Register;
-use mshv_bindings::*;
 
 pub struct MshvEmulatorContext<'a> {
     pub vcpu: &'a MshvVcpu,

hypervisor/src/mshv/x86_64/mod.rs

@@ -7,11 +7,13 @@
 // Copyright 2018-2019 CrowdStrike, Inc.
 //
 //
+use std::fmt;
+
+use serde::{Deserialize, Serialize};
+
 use crate::arch::x86::{
     CpuIdEntry, DescriptorTable, FpuState, LapicState, MsrEntry, SegmentRegister, SpecialRegisters,
 };
-use serde::{Deserialize, Serialize};
-use std::fmt;
 
 pub mod emulator;