Some block devices (ZFS volume) may require BLKDISCARD and BLKZEROOUT
ioctls for discard and write_zeroes operations respectively.
There is no good way to probe whether fallocate is supported on a block
device. Arguably, punch_hole and write_zeroes are rare. Instead of
having a complex scheme for the IO uring backend, we force it to always
use ioctls. The code can be changed if the synchronized ioctls become a
performance issue.
Changes:
- Detect block devices at construction time
- Use BLKDISCARD ioctl for punch_hole (discard) on block devices
- Use BLKZEROOUT ioctl for write_zeroes on block devices
- Add BLKDISCARD/BLKZEROOUT to VirtioBlock seccomp whitelist
- Keep fallocate() path for regular files (no behavior change)
- Consolidate some helper functions to the new sparse module
Signed-off-by: Wei Liu <liuwe@microsoft.com>
Update open_raw to construct RawDisk instead of choosing between
RawFileDisk, RawFileDiskSync and RawFileDiskAio. The backend decision
is now made inside RawDisk::create_async_io.
Remove the DiskFile wrapper structs from raw_sync.rs, raw_async.rs
and raw_async_aio.rs. Only the AsyncIo worker structs remain in those
files. Reduce their module visibility to pub(crate).
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The new_ prefix in Rust conventionally denotes constructors that return
Self (e.g. Vec::new(), File::new()). AsyncDiskFile::new_async_io does
not return Self. It is a factory method that constructs and returns a
Box<dyn AsyncIo> worker bound to the disk file descriptor and
metadata. The create_ prefix communicates this: the caller receives
a freshly constructed object of a different type.
This rename touches every format backend in block plus two external
callers in virtio-devices and performance-metrics. Every change is a
mechanical s/new_async_io/create_async_io/ substitution. No functional
change.
Ref: #7877 (task 3.2.8)
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Change the return type of RawFileAsyncAio::new() from
std::io::Result<Self> to BlockResult<Self>, wrapping
internal errors from EventFd::new() and IoContext::new()
in BlockError with DiskFileError::NewAsyncIo.
This simplifies the caller in AsyncDiskFile::new_async_io()
which no longer needs its own error mapping.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Remove the old async_io::DiskFile trait implementation from
RawFileDiskAio, now that the new disk_file trait hierarchy
is fully implemented.
Clean up unused imports: DiskFile and DiskFileResult from
crate::async_io.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::AsyncDiskFile trait implementation for
RawFileDiskAio with try_clone() and new_async_io() methods.
try_clone() duplicates the underlying file descriptor and
wraps it in a new RawFileDiskAio. new_async_io() creates a
RawFileAsyncAio (Linux AIO) backend, wrapping errors in
BlockError instead of DiskFileError.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add empty disk_file::DiskFile impl for RawFileDiskAio.
This marker supertrait requires DiskSize + Geometry + Sync,
all of which are now satisfied.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::Resizable trait implementation for
RawFileDiskAio. Calls file.set_len(size) and wraps the
I/O error in BlockError on failure.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::SparseCapable trait implementation for
RawFileDiskAio. Delegates to probe_sparse_support() to
detect whether the underlying file supports hole-punching.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::Geometry trait implementation for
RawFileDiskAio. Probes disk topology from the file,
falling back to defaults on failure. Takes &self instead
of &mut self and uses unwrap_or_else for cleaner error
handling.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::DiskFd trait implementation for
RawFileDiskAio. Delegates to file.as_raw_fd() via
BorrowedDiskFd, taking &self instead of &mut self.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::PhysicalSize trait implementation for
RawFileDiskAio. Returns the physical size from
query_device_size wrapped in BlockError on failure,
consistent with the DiskSize impl.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add disk_file::DiskSize trait implementation for
RawFileDiskAio using BlockError and BlockResult. Takes
&self instead of &mut self.
Add BlockError, BlockErrorKind, BlockResult, and disk_file
imports needed by this and subsequent trait impls.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Add #[derive(Debug)] to RawFileDiskAio. This is required
by the new disk_file traits which have Send + Debug bounds.
Signed-off-by: Muminul Islam <muislam@microsoft.com>
Use query_device_size() instead of seek(End(0)) and metadata().len()
to correctly handle block device and regular file handles.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Collect up to 32 completions per io_getevents call instead of one
at a time, buffering them in the existing VecDeque. This reduces
syscalls from 128 to 4 per drain cycle at the default queue depth.
The stack cost is 1 KB per call.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
raw_sync, raw_async, and raw_async_aio each defined
FALLOC_FL_PUNCH_HOLE, FALLOC_FL_KEEP_SIZE, and FALLOC_FL_ZERO_RANGE as
local constants in their punch_hole() and write_zeroes()
implementations. These are available from the libc crate directly.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Replace duplicated test bodies with thin wrappers that construct
the backend-specific AsyncIo instance and delegate to the shared
raw_async_io_tests helpers.
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
The AIO block backend advertises VIRTIO_BLK_F_WRITE_ZEROES
and VIRTIO_BLK_F_DISCARD to guests because the filesystem
probe (supports_sparse_operations) returns true on ext4/XFS.
However, RawFileAsyncAio::write_zeroes() and punch_hole()
return errors because Linux AIO (io_submit) has no IOCB
command for fallocate.
When io_uring is unavailable (e.g. io_uring_disabled=2, a
common security hardening on enterprise Linux), Cloud
Hypervisor falls back to the AIO backend. The guest
negotiates the feature, issues WRITE_ZEROES requests, and
gets I/O errors.
Implement write_zeroes and punch_hole using synchronous
libc::fallocate() calls, matching the pattern used by the
sync backend (RawFileSync). A VecDeque-based completion
list signals results to the caller via the existing eventfd
mechanism.
Unit tests mirror the existing raw_sync.rs test suite.
Integration tests add AIO-specific variants of the discard
and fstrim tests using _disable_io_uring=on.
Signed-off-by: Emir Beganovic <beganovic.emir@gmail.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>
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>
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>
