Introduce ExecuteError::UnsupportedFlags to carry both the
request type and the rejected flags value, replacing the
generic ExecuteError::Unsupported at discard and write zeroes
flag validation sites. This provides structured context for
debugging without changing the returned VIRTIO_BLK_S_UNSUPP
status.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The virtio spec v1.2 in 5.2.6.2 requires that the device
MUST return VIRTIO_BLK_S_UNSUPP for write zeroes commands
if any unknown flag is set.
Add an early check that rejects requests with reserved flag
bits set by returning VIRTIO_BLK_S_UNSUPP via the existing
ExecuteError::Unsupported variant.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The virtio spec v1.2 in 5.2.6.2 requires that the device
MUST return VIRTIO_BLK_S_UNSUPP for discard commands if the
unmap flag is set or if any unknown flag is set.
The discard handler was not reading the flags field at all,
silently accepting requests with arbitrary flags. Read and
validate the flags, rejecting any non-zero value with
VIRTIO_BLK_S_UNSUPP.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add a shared helper that returns the logical size in bytes for both
regular files and block devices using an immutable &File reference.
Regular files use metadata().len(). Block devices use the BLKGETSIZE64
ioctl. Any other file type returns an InvalidInput error.
This avoids seek(SeekFrom::End(0)) which requires &mut self and can
return incorrect results for block devices when the file position is
in an unexpected state.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Include the number of segments found in the request payload in
the TooManySegments error variant so the logged message shows
both the actual and maximum values.
Suggested-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Introduce DISCARD_WZ_MAX_PAYLOAD as the precomputed product of
DISCARD_WZ_SEG_SIZE and MAX_DISCARD_WRITE_ZEROES_SEG. Use it in the
DISCARD and WRITE_ZEROES segment count checks instead of repeating
the multiplication inline.
Suggested-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add range validation for DISCARD and WRITE_ZEROES, matching the
existing check in the read/write path. Per virtio spec section
5.2.6.1, a driver must not submit a request which would cause a
read or write beyond capacity. Use checked_add to guard against
overflow, then compare against disk_nsectors.
Without this, requests beyond device capacity pass through to the
host punch_hole/write_zeroes calls, relying on backend specific
behavior rather than returning VIRTIO_BLK_S_IOERR consistently.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Split the data length check into two conditions:
- reject descriptors shorter than one
virtio_blk_discard_write_zeroes segment, and
- reject payloads exceeding MAX_DISCARD_WRITE_ZEROES_SEG segments
Previously only the minimum length was checked and extra segments
were silently dropped.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Composable disk capability traits with DiskFile as a supertrait
bundling DiskSize and Geometry. Optional capabilities are
separate traits: PhysicalSize, DiskFd, SparseCapable, Resizable.
AsyncDiskFile extends DiskFile with async I/O construction.
Empty module with doc comment, trait definitions follow.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Replace magic numeric offsets with mem::offset_of!() referencing the
virtio_blk_discard_write_zeroes struct from the virtio-bindings crate
when reading the sector, num_sectors and flags fields in the DISCARD
and WRITE_ZEROES request handlers.
No functional change.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The write zeroes segment descriptor (struct
virtio_blk_discard_write_zeroes, virtio spec v1.2 section 5.2.6)
includes a flags field with an unmap bit. Per section 5.2.6.2, if
unmap is set, the device MAY deallocate the specified range of
sectors in the device backend storage, as if the discard command
had been sent.
Read the flags field and when the unmap bit is set, use punch_hole
to deallocate the range. Otherwise continue using write_zeroes via
ZERO_RANGE which preserves allocation.
This allows the guest to reclaim host disk space through write
zeroes requests on thin provisioned images.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
probe_file_sparse_support() defined FALLOC_FL_KEEP_SIZE,
FALLOC_FL_PUNCH_HOLE, and FALLOC_FL_ZERO_RANGE as local constants.
These are available from the libc crate directly.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add raw_async_io_tests.rs with punch_hole, write_zeroes, and
multiple_operations helpers that take &mut dyn AsyncIo + &mut File.
These are raw-backend-specific. They verify data by reading the
underlying file directly, which only works for plain file backends
without container format metadata.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add a small helper in the block crate that opens a disk image
file and wraps any failure in a BlockError carrying the file
path and operation context. Use it from the vmm device manager
so that a failed open now reports which path couldn't be opened.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Convert detect_image_type() from io::Result to BlockResult so
that I/O failures carry the operation name in the error context.
Update the corresponding vmm error variant to wrap BlockError.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Introduce error.rs as the home for a unified error hierarchy that
will replace the per format error types at the public crate
boundary. This commit is intentionally empty beyond the copyright
header and module declaration in lib.rs.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Test valid power of two alignment, layout compatibility,
direct helper coverage, and O_DIRECT write/read roundtrip.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
DiskTopology::probe() returned a hardcoded 512 for regular files,
causing O_DIRECT failures on volumes with larger block sizes
(e.g. 4K).
Use statx(STATX_DIOALIGN) (Linux >= 6.1) to query the real per file
DIO memory and offset alignment. Unlike fstatvfs().f_bsize, which
only returns the filesystem preferred I/O block size,
STATX_DIOALIGN reports the true DIO constraints accounting for the
filesystem, underlying block device, and any stacking (loop, dm,
etc.).
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
O_DIRECT requires buffer addresses to be aligned to the backend
device's logical block size. The existing bounce buffer logic in
execute_async() hardcodes SECTOR_SIZE (512) for the alignment check
and bounce buffer allocation. This is insufficient for devices with
a 4096-byte logical block size, where misaligned buffers cause
-EINVAL from the host kernel.
Add an alignment() method to the AsyncIo trait that returns the
backend's logical block size, defaulting to SECTOR_SIZE. The three
raw I/O backends (io_uring, AIO, synchronous) probe the device
topology via DiskTopology::probe() at creation time and return the
actual logical block size. All image format backends would simply
use the default value of 512 bytes since their underlying are
not block devices.
execute_async() now queries disk_image.alignment() instead of using
the hardcoded SECTOR_SIZE
Fixes: #7720
Signed-off-by: Saravanan D <saravanand@crusoe.ai>
There is no non destructive readonly ioctl to query block device
discard or write zeroes capabilities. BLKZEROOUT is guaranteed to
succeed via kernel software fallback. BLKDISCARD may fail at runtime
with EOPNOTSUPP on devices that lack trim support, but the error
propagates to the guest as VIRTIO_BLK_S_IOERR and well behaved
guests handle it gracefully.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
As well as rejecting writes to sector 0 in the case of raw files where
the user hasn't specified the image_type also reject virtio requests of
type discard and write_zeroes.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Add an image_type to DiskConfig to specify the image type. If none is
specified autodetect the image type but disable potentially unsafe
behaviour in the QCOW2 backend by disabling the backing file support.
If the image type is autodetected then fix it in the config so that it
will be persistant across reboots and migrations/snapshot & restores.
This also handles the case where the image type was not specified as
part of the disk configuration.
Signed-off-by: Rob Bradford <rbradford@meta.com>
Add VIRTIO_BLK_T_DISCARD and VIRTIO_BLK_T_WRITE_ZEROES request types.
Parse discard/write_zeroes descriptors (sector, num_sectors, flags),
convert to byte offsets, and call punch_hole/write_zeroes on the disk
backend. Mark as unsupported in sync mode.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
When sparse=false is configured, preallocate the entire raw disk file
at startup using fallocate(). This provides space reservation and
reduces fragmentation.
Only applies to raw disks. QCOW2/VHD/VHDX formats manage their own
allocation.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Add functions to probe whether a file or block device actually
supports PUNCH_HOLE and ZERO_RANGE operations at runtime. The
probe is performed at file open time by testing the operations
at EOF with a zero-length range, which is a safe no-op.
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>
https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7294 adjusted
the checks for read-only requests made to virtio-blk devices and started
rejecting VIRTIO_BLK_T_GET_ID requests. These requests do not perform
any writes and are needed in order to access device serials from within
the guest.
Signed-off-by: Connor Brewster <cbrewster@hey.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
This should be guaranteed by GuestMemory and GuestMemoryRegion, but
those traits are currently safe, so add checks to guard against
incorrect implementations of them.
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.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>
Cache and batch IO requests after parsing all
items in the queue, improving performance—especially
for small block sizes—by reducing per-request overhead.
Introduced two methods in the AsyncIo trait for batch
submission, with implementation in the raw disk backend.
This method should be called during/after parsing all block IO requests
in the available queue. If the batch submission is not enabled, by
default it does the old way of submitting requests.
Signed-off-by: Bo Chen <bchen@crusoe.ai>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Instead of returning boolean return an struct of completion status
so that it can be cached for batch submission.
Signed-off-by: Bo Chen <bchen@crusoe.ai>
Signed-off-by: Muminul Islam <muislam@microsoft.com>
This patch changes the read-only check using acked features bit, which
will help to check more features.
Signed-off-by: Songqian Li <sionli@tencent.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>
Recently vfio crates have moved to crates.io, thus we should start
consuming the crate from crates.io instead git url.
This results in better versioning instead of tracking some git commit
sha.
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Cargo fuzz build report an error:
error: lifetime flowing from input to output with different syntax can be confusing
--> /home/runner/work/cloud-hypervisor/cloud-hypervisor/block/src/lib.rs:747:13
|
747 | fn file(&mut self) -> MutexGuard<F>;
| ^^^^^^^^^ ------------- the lifetime gets resolved as `'_`
| |
| this lifetime flows to the output
error: lifetime flowing from input to output with different syntax can be confusing
--> /home/runner/work/cloud-hypervisor/cloud-hypervisor/block/src/async_io.rs:68:11
|
68 | fn fd(&mut self) -> BorrowedDiskFd;
| ^^^^^^^^^ -------------- the lifetime gets resolved as `'_`
| |
| this lifetime flows to the output
Signed-off-by: Yi Wang <foxywang@tencent.com>
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
