Rather than instantiating a vector for parsing the descriptor chain in
advance instead use a SmallVec bounded by the expected length of the
descriptor chain. This removes vector allocations from those paths.
As smallvec was already a block dependency move it to a workspace
dependency and use it from there.
Fixes: #5079
Signed-off-by: Rob Bradford <rbradford@meta.com>
Import the modules used in the crate instead of spelling the full paths
at every use site, and drop the now-unnecessary crate-level
#![expect(clippy::absolute_paths)].
Signed-off-by: Henry Hrvoje Tonkovac <htonkovac@gmail.com>
Assisted-by: Claude:Opus-4.8
Convert the still-needed #[allow]s to #[expect] so they warn if the
lints stop firing.
Part of #8326.
Signed-off-by: Tushar Khatri <hello@tusharkhatri.in>
Take the recent thread refactor further. Bundle a device's worker
JoinHandles together with the kill event that stops them into a single
WorkerThreads value, owned by VirtioCommon. Its Drop signals the workers
to exit, unparks any parked for migration, and joins them.
This makes a detached/leaked worker unrepresentable. reset(),
wait_for_epoll_threads() and VhostUserCommon::shutdown() now happen when
dropping the WorkerThreads, and the unpark-before-join teardown now
lives in one place.
Assisted-by: Claude:Opus-4.8
Signed-off-by: Dylan Reid <dgreid@fb.com>
Signed-off-by: Rob Bradford <rbradford@meta.com>
Replace use of spawn_virtio_thread() helper with the new method on
VirtioCommon to handle thread management as well as spawning. As a
result this cleanly handles reset if it fails to spawn the thread.
Assisted-by: Claude:Opus-4.7
Signed-off-by: Rob Bradford <rbradford@meta.com>
Replace manual translate_gva calls in both input and output queue
handlers with checked_iter for centralized range validation.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Address translation, guest memory read, write, and flush failures on
the transmitq propagated errors that killed the console device thread.
A host-side I/O error such as a PTY disconnect would permanently
disable the console. Log warnings and continue processing instead.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:claude-opus-4-6
Address translation or guest memory write failures on the receiveq
propagated errors that killed the console device thread. Log a
warning and break out of the descriptor loop instead.
Also fix a data-loss bug: bytes were drained from the input buffer
before the write to guest memory, so a failed write would silently
discard the data. Copy first, write, then drain only on success.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:claude-opus-4-6
The output queue handler read data from every descriptor without
checking the write-only flag. The driver must not put device-writable
buffers in the transmitq. Skip them with a warning.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:claude-opus-4-6
The input queue handler wrote data to every descriptor without
checking the write-only flag. The device must not write to
device-readable buffers. Skip them with a warning.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Assisted-by: Claude:claude-opus-4-6
Worker threads spawned through spawn_virtio_thread previously wrote to
exit_evt on any clean Err return, taking the whole VMM down on a single
failed device worker. A guest induced fault in any virtio device thus
propagated into a host wide failure.
Route the Err return through the shared mark_device_needs_reset helper
instead. The helper sets the DEVICE_NEEDS_RESET bit on device_status
and triggers a config change interrupt, so the device goes idle and
the guest is informed. The thread exits cleanly without killing the
rest of the VMM.
The panic and the seccomp filter apply paths keep writing to exit_evt.
A panicked worker may have left poisoned locks or partially mutated
state, so a hard exit remains the right policy there.
spawn_virtio_thread now takes the device_status and the interrupt
callback. Every native virtio and vhost-user call site is updated to
pass them in.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Previously the interrupt was created in VirtioPciDevice, moved via the
Option::take() to the VirtioPciDeviceActivator and then moved to the
VirtioDevice upon activation. On reset it would be moved back ready for
reactivation.
Since this already an Arc type remove the wrapping Option and instead
refcount it such that the VirtioPciDevice can continue to hold onto it
for later activations.
This significantly simplifies the reset() logic as there is no need to
hand back the interrupt.
A few devices used whether the interrupt was Some to make triggering an
interrupt a no-op. However the MSI-X interrupt routing already drops the
interrupt if the driver hasn't yet configured the vector so it is safe
to trigger the interrupt before device activation (e.g. balloon resize
request before driver loaded).
VirtioCommon still retains an Option<..> for the interrupt as the
interrupt is not known until activation time (after this has been
created). A helper VirtioCommon::trigger_interrupt() has been added to
handle this.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Rename from iommu to access_platform_enabled. The original name was
iommu as this feature was exposed for devices behind an IOMMU however
this feature is also now used for confidential VMs so adopt a more
general name.
Signed-off-by: Rob Bradford <rbradford@meta.com>
This forwards through to the VirtioCommon implementation and can be used
to simplify the virtio PCI access code.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Use the new virtio feature gated accessor when creating the handlers for
the virtio devices. This now means that the translations via the
accessor will only be applied if the feature is acked in accordance with
the spec.
Signed-off-by: Rob Bradford <rbradford@meta.com>
The address that is passed from the guest should be treated as
untrusted. Currently an invalid address will panic the VMM. This only
allows the guest to hurt itself, but we shouldn't have the VMM crashing.
Instead let's return an error if possible or invalidate the queue if it
happen during setup.
The data flow from guest to translate_gva/translate_gpa is:
1. Guest writes a raw u64 address into a virtio descriptor in the
shared descriptor table (guest memory).
2. The virtio-queue crate reads this descriptor via read_obj() and
returns the addr field as-is in a GuestAddress — no validation.
3. Device code calls .translate_gva(access_platform, len) on the
GuestAddress.
4. With IOMMU (access_platform is Some): the address is an IOVA that
must be translated to a GPA via the IOMMU mapping table. If the
guest provides an unmapped IOVA, translation returns Err.
Previously, .unwrap() here panicked the VMM.
5. Without IOMMU (access_platform is None): translate_gva is a no-op
(returns self). The raw address flows to GuestMemory::read_obj()
which validates it — out-of-range addresses return
Err(InvalidGuestAddress), so no host memory corruption is possible.
Signed-off-by: Dylan Reid <dgreid@fb.com>
Bump to the released versions that are compatible wherever possible but
for the vhost and vfio crates they are git hashes as no releases with
compatible versions have yet been made.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Both process_input_queue and process_output_queue were only processing
the first descriptor of a chain, leading to data loss if the driver used
chained descriptors.
This change iterates through all descriptors in a chain. It also moves
the flush call out of the descriptor loops to improve performance.
Signed-off-by: Andrei Vagin <avagin@google.com>
For a transmit queue (guest to host), the host only reads from the
guest-provided buffers and does not write to them. According to the
virtio specification (e.g., Section 2.6.8 in Virtio 1.1), the 'len'
field in the used ring has to be set to the number of bytes written to
the buffers. Therefore, it should be 0 for the console transmit queue.
Signed-off-by: Andrei Vagin <avagin@google.com>
The update_console_size method was using fetch_and on the acked_features
atomic, which modified the atomic and cleared other feature bits.
Changed it to use a non-destructive load and bitwise AND.
Signed-off-by: Andrei Vagin <avagin@google.com>
Rename the transport feature bit constant from
VIRTIO_F_IOMMU_PLATFORM to VIRTIO_F_ACCESS_PLATFORM across
the entire virtio-devices crate.
The virtio specification as of v1.1 carries bit 33 as
VIRTIO_F_ACCESS_PLATFORM. The Linux kernel UAPI header
<linux/virtio_config.h> carries VIRTIO_F_IOMMU_PLATFORM
only as a backward-compatible alias.
This is a pure rename with no functional or behavioral
change.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
This is a follow-up of [0].
# Advantages
- This saves dozens of unneeded clone()s across the whole code base
- Makes it much easier to reason about how parameters are used
(often we passed owned Arc/Rc versions without actually needing
ownership)
# Exceptions
For certain code paths, the alternatives would require awkward or overly
complex code, and in some cases the functions are the logical owners of
the values they take. In those cases, I've added
#[allow(clippy::needless_pass_by_value)].
This does not mean that one should not improve this in the future.
[0] 6a86c157af
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
Consuming `&Arc<T>` as argument is almost always an antipattern as it
hides whether the callee is going to take over (shared) ownership
(by .clone()) or not. Instead, it is better to consume `&dyn T` or
`Arc<dyn T>` to be more explicit. This commit cleans up the code.
The change is very mechanic and was very easy to implement across the
code base.
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>
This streamlines the code base to follow best practices for
error handling in Rust: Each error struct implements
std::error::Error (most due via thiserror::Error derive macro)
and sets its source accordingly.
This allows future work that nicely prints the error chains,
for example.
So far, the convention is that each error prints its
sub error as part of its Display::fmt() impl.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
By introducing `imports_granularity="Module"` format strategy,
effectively groups imports from the same module into one line or block,
improving maintainability and readability.
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>
Rebooting a VM fails with the following error when debug assertions
are enabled:
fatal runtime error: IO Safety violation: owned file descriptor already closed
This happens because FromRawFd::from_raw_fd is used on RawFds stored
in ConsoleInfo every time a VM begins to boot, so the second
time (after a reboot, or if the first attempt to boot via the API
failed), the fd will be closed. Until this assertion is hit, the code
is operating on either closed file descriptors, or new file
descriptors for something completely different. If debug assertions
are disabled, it will just continue doing this with unpredictable
results.
To fix this, and prevent the problem reocurring, ownership of the
console file descriptors needs to be properly tracked, using Rust's
type system, so this commit refactors the console code to do that.
The file descriptors are now passed around with reference counts, so
they won't be closed prematurely. The obvious way to do this would be
to just have each member of ConsoleInfo be an Arc<File>, but we need
to accomodate that serial console file descriptors can also be
sockets. We can't just store an OwnedFd and convert it when it's
used, because we only get a reference from the Arc, so we need to
store the descriptors as their concrete types in an enum. Since this
basically duplicates the ConsoleOutputMode enum from the config, the
ConsoleOutputMode enum is now not used past constructing the
ConsoleInfo.
So that ownership can be represented consistently, the debug console's
tty mode now uses its own stdout descriptor.
I'm still using .try_clone().unwrap() (i.e. dup()) to clone file
descriptors for Endpoint::FilePair and Endpoint::TtyPair, because I
assume there's a reason for them not just to hold a single file
descriptor.
I've also retained the existing behaviour of having serial manager
ignore the tty file descriptor passed to it (which is stdout), and
instead using stdin. It looks a lot weirder now, because it has to
explicitly indicate it's ignoring the fd with an underscore binding.
Fixes: 52eebaf6 ("vmm: refactor DeviceManager to use console_info")
Signed-off-by: Alyssa Ross <hi@alyssa.is>
TIOCGWINSZ modifies its argument, so it needs to mutably borrow it.
Unfortunately, ioctl()'s signature is not able to enforce this, and
the write happens in the kernel, so I don't think anything like miri,
valgrind, UBSan, etc. would have been able to catch this.
The UB passing an immutable reference caused resulted, for me, in
get_win_size() returning (0, 0) since LLVM commit
9a09c737a052 ("[BasicAA] Make isNotCapturedBeforeOrAt() check for
calls more precise (#69931)").
I've had a look through the other ioctl() calls in Cloud Hypervisor,
and I don't think any others have the same problem.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
This change is important to do a proper resource cleanup. We decided
to do this repetitive approach as VirtioCommon can't implement Drop
without major changes to the corresponding code. Also, devices such as
Net can't easily use the epoll_threads-abstraction from VirtioCommon as
it has multiple threads with different semantics.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
The information about the identifier related to a Snapshot is only
relevant from the BTreeMap perspective, which is why we can get rid of
the duplicated identifier in every Snapshot structure.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Following the new restore design, it is not appropriate to set every
virtio device threads into a paused state after they've been started.
This is why we remove the line of code pausing the devices only after
they've been restored, and replace it with a small patch in every virtio
device implementation. When a virtio device is created as part of a
restored VM, the associated "paused" boolean is set to true. This
ensures the corresponding thread will be directly parked when being
started, avoiding the thread to be in a different state than the one it
was on the source VM during the snapshot.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Since the processing of the console inputs was moved from the VMM thread
to the virtio-console thread (#3061), we have been using the 'FILE_EVENT'
to handle input from stdin/pty/file, which made 'INPUT_EVENT' obsoleted.
Signed-off-by: Bo Chen <chen.bo@intel.com>
Following the new design proposal to improve the restore codepath when
migrating a VM, all virtio devices are supplied with an optional state
they can use to restore from. The restore() implementation every device
was providing has been removed in order to prevent from going through
the restoration twice.
Here is the list of devices now following the new restore design:
- Block (virtio-block)
- Net (virtio-net)
- Rng (virtio-rng)
- Fs (vhost-user-fs)
- Blk (vhost-user-block)
- Net (vhost-user-net)
- Pmem (virtio-pmem)
- Vsock (virtio-vsock)
- Mem (virtio-mem)
- Balloon (virtio-balloon)
- Watchdog (virtio-watchdog)
- Vdpa (vDPA)
- Console (virtio-console)
- Iommu (virtio-iommu)
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The the number of queues and associated events is known and fixed. We
can define and use each of them explicitly and avoid using vector (and
hence direct indexing), which is cleaner and slightly more efficient.
Signed-off-by: Bo Chen <chen.bo@intel.com>
