The swtpm control socket is a Unix SOCK_STREAM, so a single read() is
not guaranteed to return the full response in one shot. swtpm may
split a response into multiple writes, in which case the existing
single read() returns only the first chunk and subsequent parsing
fails with "Response for ... cmd is of incorrect length". This has
been observed on Azure Linux during emulator initialization.
In addition, when swtpm encounters an error processing a control
command (e.g. PTM_BAD_ORDINAL = 0x0A returned for commands issued
before CMD_INIT), the swtpm protocol returns only the 4-byte result
code instead of the full response. Blindly looping until msg_len_out
bytes arrive would deadlock in that case.
Add SocketDev::read_exact() that loops until the requested number of
bytes has been received (retrying on EINTR), and rework
run_control_cmd() to:
* read_exact the 4-byte result code first;
* on error, set the result code on the PTM message and return a
clean error without waiting for a payload that will never arrive;
* on success, read_exact the remaining (msg_len_out - 4) payload
bytes.
Assisted-by: Copilot:GPT-5.5
Signed-off-by: Wei Liu <liuwe@microsoft.com>
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
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>
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>
The largest possible PTM response is only 16 bytes. Size the output
buffer correctly.
In the socket read function, rely on the caller to provide a
sufficiently large buffer. That eliminates another large stack variable.
In total this saves almost 8KB stack space.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Add SocketDev struct. Methods in SocketDev will be used to read & write
to Ctrl channel created by swtpm.
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-authored-by: Sean Yoo <t-seanyoo@microsoft.com>
