misc: Fix various warnings from clippy 0.1.82

An example warning output is:

error: first doc comment paragraph is too long
   --> virtio-devices/src/lib.rs:158:1
    |
158 | / /// Convert an absolute address into an address space (GuestMemory)
159 | | /// to a host pointer and verify that the provided size define a valid
160 | | /// range within a single memory region.
161 | | /// Return None if it is out of bounds or if addr+size overlaps a single region.
    | |_
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph
    = note: `-D clippy::too-long-first-doc-paragraph` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::too_long_first_doc_paragraph)]`

Signed-off-by: Bo Chen <chen.bo@intel.com>

arch/src/x86_64/mod.rs

@@ -905,6 +905,7 @@ pub fn configure_vcpu(
 }
 
 /// Returns a Vec of the valid memory addresses.
+///
 /// These should be used to configure the GuestMemory structure for the platform.
 /// For x86_64 all addresses are valid from the start of the kernel except a
 /// carve out at the end of 32bit address space.

hypervisor/src/kvm/aarch64/mod.rs

@@ -82,6 +82,7 @@ macro_rules! arm64_core_reg_id {
 }
 
 /// Specifies whether a particular register is a system register or not.
+///
 /// The kernel splits the registers on aarch64 in core registers and system registers.
 /// So, below we get the system registers by checking that they are not core registers.
 ///

pci/src/configuration.rs

@@ -180,8 +180,10 @@ impl PciSubclass for PciNetworkControllerSubclass {
     }
 }
 
-/// A PCI class programming interface. Each combination of `PciClassCode` and
-/// `PciSubclass` can specify a set of register-level programming interfaces.
+/// Trait to define a PCI class programming interface
+///
+/// Each combination of `PciClassCode` and `PciSubclass` can specify a
+/// set of register-level programming interfaces.
 /// This trait is implemented by each programming interface.
 /// It allows use of a trait object to generate configurations.
 pub trait PciProgrammingInterface {
@@ -418,6 +420,7 @@ pub struct PciConfigurationState {
 }
 
 /// Contains the configuration space of a PCI node.
+///
 /// See the [specification](https://en.wikipedia.org/wiki/PCI_configuration_space).
 /// The configuration space is accessed with DWORD reads and writes from the guest.
 pub struct PciConfiguration {

rate_limiter/src/group.rs

@@ -43,10 +43,11 @@ pub enum Error {
     EventFdWrite(#[source] io::Error),
 }
 
-/// The RateLimiterGroupHandle is a handle to a RateLimiterGroup that may be
-/// used in exactly the same way as the RateLimiter type. When the RateLimiter
-/// within a RateLimiterGroup is unblocked, each RateLimiterGroupHandle will
-/// be notified.
+/// Handle to a RateLimiterGroup
+///
+/// The RateLimiterGroupHandle may be used in exactly the same way as
+/// the RateLimiter type. When the RateLimiter within a RateLimiterGroup
+/// is unblocked, each RateLimiterGroupHandle will be notified.
 pub struct RateLimiterGroupHandle {
     eventfd: Arc<EventFd>,
     inner: Arc<RateLimiterGroupInner>,

virtio-devices/src/device.rs

@@ -177,6 +177,8 @@ pub trait VirtioDevice: Send {
     fn set_access_platform(&mut self, _access_platform: Arc<dyn AccessPlatform>) {}
 }
 
+/// Trait to define address translation for devices managed by virtio-iommu
+///
 /// Trait providing address translation the same way a physical DMA remapping
 /// table would provide translation between an IOVA and a physical address.
 /// The goal of this trait is to be used by virtio devices to perform the

virtio-devices/src/lib.rs

@@ -155,6 +155,8 @@ impl TryInto<rate_limiter::RateLimiter> for RateLimiterConfig {
     }
 }
 
+/// Return the host virtual address corresponding to the given guest address range
+///
 /// Convert an absolute address into an address space (GuestMemory)
 /// to a host pointer and verify that the provided size define a valid
 /// range within a single memory region.

virtio-devices/src/vsock/mod.rs

@@ -115,6 +115,7 @@ pub enum VsockEpollHandlerError {
 }
 
 /// A passive, event-driven object, that needs to be notified whenever an epoll-able event occurs.
+///
 /// An event-polling control loop will use `get_polled_fd()` and `get_polled_evset()` to query
 /// the listener for the file descriptor and the set of events it's interested in. When such an
 /// event occurs, the control loop will route the event to the listener via `notify()`.
@@ -130,8 +131,9 @@ pub trait VsockEpollListener {
     fn notify(&mut self, evset: epoll::Events);
 }
 
-/// Any channel that handles vsock packet traffic: sending and receiving packets. Since we're
-/// implementing the device model here, our responsibility is to always process the sending of
+/// Trait to describe any channel that handles vsock packet traffic (sending and receiving packets)
+///
+/// Since we're implementing the device model here, our responsibility is to always process the sending of
 /// packets (i.e. the TX queue). So, any locally generated data, addressed to the driver (e.g.
 /// a connection response or RST), will have to be queued, until we get to processing the RX queue.
 ///
@@ -151,8 +153,9 @@ pub trait VsockChannel {
     fn has_pending_rx(&self) -> bool;
 }
 
-/// The vsock backend, which is basically an epoll-event-driven vsock channel, that needs to be
-/// sendable through a mpsc channel (the latter due to how `vmm::EpollContext` works).
+/// The vsock backend, which is basically an epoll-event-driven vsock channel
+///
+/// It that needs to be sendable through a mpsc channel (the latter due to how `vmm::EpollContext` works).
 /// Currently, the only implementation we have is `crate::virtio::unix::muxer::VsockMuxer`, which
 /// translates guest-side vsock connections to host-side Unix domain socket connections.
 pub trait VsockBackend: VsockChannel + VsockEpollListener + Send {}

vm-device/src/dma_mapping/mod.rs

@@ -2,6 +2,8 @@
 //
 // SPDX-License-Identifier: Apache-2.0 OR BSD-3-Clause
 
+/// Trait to trigger DMA mapping updates for devices managed by virtio-iommu
+///
 /// Trait meant for triggering the DMA mapping update related to an external
 /// device not managed fully through virtio. It is dedicated to virtio-iommu
 /// in order to trigger the map update anytime the mapping is updated from the

vm-migration/src/lib.rs

@@ -63,6 +63,7 @@ pub trait Pausable {
 }
 
 /// A Snapshottable component snapshot section.
+///
 /// Migratable component can split their migration snapshot into
 /// separate sections.
 /// Splitting a component migration data into different sections
@@ -94,6 +95,8 @@ impl SnapshotData {
     }
 }
 
+/// Data structure to describe snapshot data
+///
 /// A Snapshottable component's snapshot is a tree of snapshots, where leafs
 /// contain the snapshot data. Nodes of this tree track all their children
 /// through the snapshots field, which is basically their sub-components.
@@ -207,8 +210,9 @@ pub trait Transportable: Pausable + Snapshottable {
     }
 }
 
-/// Trait to be implemented by any component (device, CPU, RAM, etc) that
-/// can be migrated.
+/// Trait to define shared behaviors of components that can be migrated
+///
+/// Examples are device, CPU, RAM, etc.
 /// All migratable components are paused before being snapshotted, and then
 /// eventually resumed. Thus any Migratable component must be both Pausable
 /// and Snapshottable.