Module blk 

Virtio-blk device driver

Implements a block device driver for virtio-blk PCI devices as described in the virtio specification, section 5.2. Supports read and write operations using the legacy (transitional) PCI transport.

Virtio-blk request format

Each request is a three-descriptor chain:

1. Header (device-readable): VirtioBlkReqHeader with request type + sector
2. Data (device-readable for write, device-writable for read): sector data
3. Status (device-writable): single byte result (0 = OK, 1 = IOERR, 2 = UNSUPP)

QEMU usage

-drive file=disk.img,if=none,id=vd0,format=raw -device virtio-blk-pci,drive=vd0

Modules

features

Virtio-blk feature bits (virtio spec 5.2.3)

Structs

VirtioBlkDevice

Virtio block device.

Constants

BLOCK_SIZE

Block size in bytes (standard sector)

Traits

BlockDevice

Block device trait for generic block I/O operations.

Functions

get_device

Get a reference to the global virtio-blk device, if initialized.

init

Probe PCI bus for virtio-blk devices and initialize the first one found.

is_initialized

Check if a virtio-blk device has been initialized.