Using directly preadv and pwritev, we can simply use a RawFd instead of
a file, and we don't need to use the more complex implementation from
the qcow crate.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit adds the asynchronous support for fixed VHD disk files.
It introduces FixedVhd as a new ImageType, moving the image type
detection to the block_util crate (instead of qcow crate).
It creates a new vhd module in the block_util crate in order to handle
VHD footer, following the VHD specification.
It creates a new fixed_vhd_async module in the block_util crate to
implement the asynchronous version of fixed VHD disk file. It relies on
io_uring.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Since QCOW and RAW synchronous implementation are very close, it makes
sense to introduce some common functions that can be shared between
these two.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the synchronous QCOW file implementation present in the qcow
crate, we created a new qcow_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.
The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the synchronous RAW file implementation present in the qcow
crate, we created a new raw_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.
The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Based on the new DiskFile and AsyncIo traits, the implementation of
asynchronous block support does not have to be tied to io_uring anymore.
Instead, the only thing the virtio-blk implementation knows is that it
is using an asynchronous implementation of the underlying disk file.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Both DiskFile and AsyncIo traits are introduced to allow all kind of
files (RAW, QCOW, VHD) to be able to handle asynchronous access to the
underlying file.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Small patch creating a dedicated `block_io_uring_is_supported()`
function for the non-io_uring case, so that we can simplify the
code in the DeviceManager.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Some operations complete directly after they have been submitted, which
means they are not submitted asynchronously and therefore they don't
generate any ioevent. This is the reason why we are not processing some
of the completed operations, which leads to some unpredictable
behaviors.
Forcing all io_uring operations submitted to the SQE to be asynchronous
helps simplifying the code as it ensures the completion of every
operation will generate an ioevent, therefore no operation is missed.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
The Windows virtio block driver puts multiple data descriptors between
the header and the status footer. To handle this when parsing iterate
over the descriptor chain until the end is reached accumulating the
address and length pairs in a vector. For execution iterate over the
vector and make sequential reads from the disk for each data descriptor.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
In anticipation for supporting multiple virtio descriptors, let's make
sure the read/write operations are performed with vectored I/O.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
By adding a new io_uring feature gate, we let the user the possibility
to choose if he wants to enable the io_uring improvements or not.
Since the io_uring feature depends on the availability on recent host
kernels, it's better if we leave it off for now.
As soon as our CI will have support for a kernel 5.6 with all the
features needed from io_uring, we'll enable this feature gate
permanently.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Creates a dedicated function relying on io_uring crate to execute
io_uring specific requests.
Also creates a function for checking io_uring support on the host.
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
Extract the code that is used by vhost_user_block from the
virtio-devices crate to remove the dependencies on unrequired
functionality such as the virtio transports.
Signed-off-by: Rob Bradford <robert.bradford@intel.com>
