Commit Graph

9 Commits

Author SHA1 Message Date
Rob Bradford
88a9f79944 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>
2024-09-29 13:08:12 +01:00
Christian Blichmann
88f3537b47 event_monitor: Replace unsound static mut MONITOR
See discussion in https://github.com/rust-lang/rust/issues/53639.
This came up during an internal review.

Signed-off-by: Christian Blichmann <cblichmann@google.com>
2023-09-14 14:08:54 +01:00
Omer Faruk Bayram
2ed96cd3ed vmm: dbus: broadcast event_monitor events over the DBus API
This commit builds on top of the `Monitor::subscribe` function and
makes it possible to broadcast events published from `event-monitor`
over D-Bus.

The broadcasting functionality is enabled if the D-Bus API is enabled
and users who wish to also enable the file based `event-monitor` can do
so with the CLI arg `--event-monitor`.

Signed-off-by: Omer Faruk Bayram <omer.faruk@sartura.hr>
2023-08-28 17:01:03 -07:00
Omer Faruk Bayram
e02efe9ba0 event_monitor: make it possible to subscribe to Monitor
Signed-off-by: Omer Faruk Bayram <omer.faruk@sartura.hr>
2023-08-28 17:01:03 -07:00
Omer Faruk Bayram
02e1c54426 event_monitor: refactor the implementation to support concurrent access
This patch modifies `event_monitor` to ensure that concurrent access to
`event_log` from multiple threads is safe. Previously, the `event_log`
function would acquire a reference to the event log file and write
to it without doing any synchronization, which made it prone to
data races. This issue likely went under the radar because the
relevant `SAFETY` comment on the unsafe block was incomplete.

The new implementation spawns a dedicated thread named `event-monitor`
solely for writing to the file. It uses the MPMC channel exposed by
`flume` to pass messages to the `event-monitor` thread. Since
`flume::Sender<T>` implements `Sync`, it is safe for multiple threads
to share it and send messages to the `event-monitor` thread.
This is not possible with `std::sync::mpsc::Sender<T>` since it's
`!Sync`, meaning it is not safe for it to be shared between different
threads.

The `event_monitor::set_monitor` function now only initializes
the required global state and returns an instance of the
`Monitor` struct. This decouples the actual logging logic from the
`event_monitor` crate. The `event-monitor` thread is then spawned by
the `vmm` crate.

Signed-off-by: Omer Faruk Bayram <omer.faruk@sartura.hr>
2023-08-09 17:22:25 +01:00
Wei Liu
b1efa5b26b event_monitor: add safety comments
Signed-off-by: Wei Liu <liuwe@microsoft.com>
2022-11-18 12:50:01 +00:00
Maksym Pavlenko
3a0429c998 cargo: Clean up serde dependencies
There is no need to include serde_derive separately,
as it can be specified as serde feature instead.

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>
2022-05-18 08:21:19 +02:00
Bo Chen
32353fa389 event_monitor: Append double newlines after each event
This allows to consume and parse the output event output file.

Signed-off-by: Bo Chen <chen.bo@intel.com>
2022-05-17 09:55:03 +02:00
Rob Bradford
ddbef7450d event_monitor: Add new crate for event reporting
This crate exposes the abililty for the VMM to set a file that events
should be written to. The event!() macro provides an interface to report
those events allowing the specification of an event source, an event
type and optional extra data. This will be written to the provided file
descriptor as JSON data.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
2021-02-18 16:15:13 +00:00