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>
Now that io-uring crate has been stabilized, let's move to the latest
release 0.4.0 from crates.io.
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>
