Reflect the latest migration protocol as mermaid diagrams in the
(code) documentation.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
This will be useful later when we rebuild the live migration code as a
state machine.
On-behalf-of: SAP julian.stecklina@sap.com
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
This helps to uncover expensive and needless clones in the code base.
For example, I prevented extensive clones in the snapshot path where
(nested) BTreeMap's have been cloned over and over again. Further,
the lint helps devs to much better reason about the ownership of
parameters.
All of these changes have been done manually with the necessary
caution. A few structs that are cheap to clone are now `copy` so that
this lint won't trigger for them.
I didn't enable the lint so far as it is a massive rabbit hole and
needs much more fixes. Nevertheless, it is very useful.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
This better aligns with the rest of the code and makes it clearer
that these tests can run "as is" in a normal hosted environments
without the special test environment.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
A major improvement to the developer experience of clippy in
Cloud Hypervisor.
1. Make `cargo clippy` just work with the same lints we use in CI
2. Simplify adding new lints
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
Adding itertools as dependency improves the iteration code in the
following significantly.
With this change, we don't need a copy of the vector. Just something
that can be coerced into an iterator. We also use the bit position
iterator to make the code somewhat clearer. The new code is much
faster, because it will not iterate over every bit, just each 1 bit in
the input.
The next commit will complete this optimization and have some concrete
numbers.
On-behalf-of: SAP julian.stecklina@sap.com
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Instead of using ad-hoc code, just write an extension to the Iterator
trait that we can easily unit test.
Co-authored-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP julian.stecklina@sap.com
On-behalf-of: SAP philipp.schuster@sap.com
Signed-off-by: Julian Stecklina <julian.stecklina@cyberus-technology.de>
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
Fix clippy warning `uninlined_format_args` reported by rustc rustc
1.89.0 (29483883e 2025-08-04).
```console
warning: variables can be used directly in the `format!` string
--> block/src/lib.rs:649:17
|
649 | info!("{} failed to create io_uring instance: {}", error_msg, e);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#uninlined_format_args
= note: `#[warn(clippy::uninlined_format_args)]` on by default
help: change this to
|
649 - info!("{} failed to create io_uring instance: {}", error_msg, e);
649 + info!("{error_msg} failed to create io_uring instance: {e}");
|
```
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
This upgrades the Cargo workspace to Rust edition 2024 to keep the
code base clean and up to date.
The commit only contains the adjustments to the Cargo.toml files and
basic compiler error fixes. Also, this commit includes new SAFETY
comments as discussed in [1]. The changes were not automatically
fixed by `cargo fix --edition` but needed manual adjustments.
Apart from that, all formatting and clippy adjustments follow in
subsequent commits.
*
As only exception, workspace member net_gen sticks to edition 2021
for now as discussed in [0].
[0] https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7295#discussion_r2310851041
[1] https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7256#issuecomment-3271888674
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
Many of the workspace members in the Cloud-hypervisor workspace share
common dependencies. Making these workspace dependencies reduces
duplication and improves maintainability.
Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de>
On-behalf-of: SAP oliver.anderson@sap.com
The changes were mostly automatically applied using the Python
script mentioned in the first commit of this series.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
As almost every sub crate depends on thiserror, lets upgrade it to a
workspace dependency.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
# What
This commit introduces file-based advisory locking for the files backing
up the block devices by using the fcntl() syscall with OFD locks. The
per-open-file-descriptor (OFD) locks are more robust than traditional
POSIX locks (F_SETLK) as they are not tied to process IDs and avoid
common issues in multithreaded or multi-fd scenarios [1]. Therefore,
we don't use `std::fs::File::try_lock()`, which is backed by F_SETLKW.
The locking mechanism is aware of the `readonly` property and allows
`n` readers or `1` writer (exclusive mode).
As the locks are advisory, multiple cloud-hypervisor processes can
prevent themselves from writing to the same file. However, this is not
a system-wide file-system level locking mechanism preventing to open()
a file.
The introduced new locking mechanism does not cover vhost-user devices.
# Why
To prevent misconfiguration and improve safety, it is good practice to
protect disk image files with a locking mechanism. Experience and common
best practices suggest that advisory locks are preferable over mandatory
locks due to better compatibility and fewer pitfalls (in fs space).
The introduced functionality is aligned with the approach taken by
QEMU [0], and is also recommended in [1].
# Implementation Details
We need to ensure that not only normal operation keeps working but also
state save/resume and live-migration. Especially for live migration,
it is crucial that the sender VMM releases the locks when the VM stops
so the receiver VMM can acquire them right after that.
Therefore, the locking and releasing happen directly on the block
device struct. The device manager knows all block devices and can
forward requests to these types.
Last but not least, this commit uses on explicit lock acquiring
but implicit lock releasing (FD close). It only explicitly releases
the locks where this integrates more smoothly into the existing
code.
# Testing
I tested
- normal operation
- state save/resume,
- device hot plugging,
- and live-migration
with read/shared and write/exclusive locks.
One can use the `fcntl-tool` to test if locks are actually acquired
or released [2].
# Links
[0] 825b96dbce/util/osdep.c (L266)
[1] https://apenwarr.ca/log/20101213
[2] https://crates.io/crates/fcntl-tool
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
`serde_json` crate is referenced by multiple components, centralize it
to workspace to better manage this crate.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
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>
Modify `Cargo.toml` in each member crate to follow the dependencies
specified in root `Cargo.toml` file.
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
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>
This method will return the existing Response if the status is
successful (Status::Ok) otherwise issue a command to abandon the
migration and return the desired error.
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
In 42e9632c53 a fix was made to address a
typo in the taplo configuration file. Fixing this typo indicated that
many Cargo.toml files were no longer adhering to the formatting rules.
Fix the formatting by running `taplo fmt`.
Signed-off-by: Rob Bradford <rbradford@rivosinc.com>
This patch bumps the following crates, including `kvm-bindings@0.7.0`*,
`kvm-ioctls@0.16.0`**, `linux-loader@0.11.0`, `versionize@0.2.0`,
`versionize_derive@0.1.6`***, `vhost@0.10.0`,
`vhost-user-backend@0.13.1`, `virtio-queue@0.11.0`, `vm-memory@0.14.0`,
`vmm-sys-util@0.12.1`, and the latest of `vfio-bindings`, `vfio-ioctls`,
`mshv-bindings`,`mshv-ioctls`, and `vfio-user`.
* A fork of the `kvm-bindings` crate is being used to support
serialization of various structs for migration [1]. Also, code changes
are made to accommodate the updated `struct xsave` from the Linux
kernel. Note: these changes related to `struct xsave` break
live-upgrade.
** The new `kvm-ioctls` crate introduced breaking changes for
the `get/set_one_reg` API on `aarch64` [2], so code changes are made to
the new APIs.
*** A fork of the `versionize_derive` crate is being used to support
versionize on packed structs [3].
[1] https://github.com/cloud-hypervisor/kvm-bindings/tree/ch-v0.7.0
[2] https://github.com/rust-vmm/kvm-ioctls/pull/223
[3] https://github.com/cloud-hypervisor/versionize_derive/tree/ch-0.1.6Fixes: #6072
Signed-off-by: Bo Chen <chen.bo@intel.com>
