Replace the clone based BackingFileOps trait with a BackingKind enum
so backing files can be decomposed into their concrete owned types.
BackingFile::new() for QCOW2 backings now calls parse_qcow() directly
instead of building a full QcowFile. Remove Clone for BackingFile and
QcowFile.
Prerequisite for the qcow_sync rewrite which decomposes a BackingFile
into a raw fd or QcowMetadata for lock free I/O.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Verify that opening a QCOW2 image with a backing file reference
through QcowDiskSync with backing_files=off produces the user-facing
BackingFilesDisabled error rather than MaxNestingDepthExceeded.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
When a QCOW2 image has a backing file but backing_files=on is not set,
the error was MaxNestingDepthExceeded which gives no indication that
this is a policy decision or how to resolve it.
Add a BackingFilesDisabled error variant whose message indicates that
backing file support is disabled and references the backing_files
option. The translation from MaxNestingDepthExceeded to
BackingFilesDisabled happens at the QcowDiskSync boundary where the
policy decision is made, preserving the original error for genuine
recursive depth exhaustion.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add comprehensive tests for DISCARD and WRITE_ZEROES operations:
QCOW2 zero flag test validates the complete workflow: allocate
cluster, DISCARD it, verify reads return zeros, write new data,
verify cluster reallocated.
QcowSync tests verify punch_hole and write_zeroes with Arc<Mutex<>>
sharing, including tests for cache consistency with multiple async
I/O operations.
RawFileSync tests verify punch_hole and write_zeroes using
fallocate.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Implement punch_hole and write_zeroes for QcowSync backend by
delegating to QcowFile::punch_hole which triggers cluster
deallocation. write_zeroes delegates to punch_hole as unallocated
clusters read as zeros in QCOW2.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add sparse parameter to QcowFile constructors and propagate it from
device_manager through QcowDiskSync. This makes the sparse configuration
available throughout the QCOW2 implementation for controlling allocation
and deallocation behavior.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add supports_zero_flag() to DiskFile trait to indicate whether a disk
format can mark clusters/blocks as reading zeros without deallocating
storage.
QCOW2 supports this via the zero flag in L2 entries. VHDX also has
PAYLOAD_BLOCK_ZERO state for this, though it's not yet implemented in
cloud-hypervisor.
This enables DISCARD to be advertised even with sparse=false for formats
with zero-flag support, since they can mark regions as zeros (keeps
storage allocated) instead of requiring full deallocation.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add capability query to DiskFile trait to check backend
support for sparse operations (punch hole, write zeroes,
discard). Only advertise VIRTIO_BLK_F_DISCARD and
VIRTIO_BLK_F_WRITE_ZEROES when the backend supports these
operations.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add punch_hole() and write_zeroes() methods to the AsyncIo trait
with stub implementations for all backends. These will be used to
support DISCARD and WRITE_ZEROES operations.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add support for live resizing QCOW2 images. This enables growing
the virtual size of a QCOW2 disk while the VM is running.
Key features:
- Growing the image automatically expands the L1 table if needed
- Shrinking is not supported
- Resizing for images with backing files is not supported
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Backing files (e.g. for QCOW2) interact badly with landlock since they
are not obvious from the initial VM configuration. Only enable their use
with an explicit option.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Wrap QcowFile in Arc<Mutex<>> to ensure thread safety when multiple
virtio queues access the same QCOW2 image concurrently.
Previously, each queue received its own QcowSync instance via
new_async_io() that shared the underlying QcowFile through Clone.
However, cloned QcowFile instances share internal mutable state
(L2 cache, reference counts, file seek position) without
synchronization, leading to data corruption under concurrent I/O.
This change serializes all QCOW2 operations through a mutex, which
ensures correctness at the cost of parallelism. A more performant
solution would require separating metadata locking from actual I/O
operations, tracked in #7560.
Related: #7560
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
It shouldn't be necessary to lock the file for the adaptor. This removes
two layers of indirection for QcowDiskSync and VhdxDiskSync.
Signed-off-by: Wei Liu <liuwe@microsoft.com>
This was caught by the nightly compiler during cargo fuzz build.
error: lifetime flowing from input to output with different syntax can be confusing
--> /home/runner/work/cloud-hypervisor/cloud-hypervisor/hypervisor/src/arch/x86/emulator/mod.rs:493:26
|
493 | pub fn new(platform: &mut dyn PlatformEmulator<CpuState = T>) -> Emulator<T> {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ----------- the lifetime gets resolved as `'_`
| |
| this lifetime flows to the output
|
= note: `-D mismatched-lifetime-syntaxes` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(mismatched_lifetime_syntaxes)]`
help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
|
493 | pub fn new(platform: &mut dyn PlatformEmulator<CpuState = T>) -> Emulator<'_, T> {
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>
This commit merges crates `qcow`, `vhdx` and `block_util` into the
crate `block`, which can allow `qcow` to use functions from `block_util`
without introducing a circular crate dependency.
This commit is based on crosvm implementation:
f2eecc4152
Signed-off-by: Yu Li <liyu.yukiteru@bytedance.com>
