Zoned Block Devices (ZBDs) devide the LBA space to block regions called zones that are larger than the LBA size. It can only allow sequential writes, which reduces write amplification in SSD, leading to higher throughput and increased capacity. More details about ZBDs can be found at:
https://zonedstorage.io/docs/introduction/zoned-storage The zoned device support aims to let guests (virtual machines) access zoned storage devices on the host (hypervisor) through a virtio-blk device. This involves extending QEMU's block layer and virtio-blk emulation code. In its current status, the virtio-blk device is not aware of ZBDs but the guest sees host-managed drives as regular drive that will runs correctly under the most common write workloads. This patch series extend the block layer APIs and virtio-blk emulation section with the minimum set of zoned commands that are necessary to support zoned devices. The commands are - Report Zones, four zone operations and Zone Append (developing). It can be tested on a null_blk device using qemu-io, qemu-iotests or blkzone(8) command in the guest os. For example, the command line for zone report using qemu-io is: $ path/to/qemu-io --image-opts driver=zoned_host_device,filename=/dev/nullb0 -c "zrp offset nr_zones" To enable zoned device in the guest os, the guest kernel must have the virtio-blk driver with ZBDs support. The link to such patches for the kernel is: https://github.com/dmitry-fomichev/virtblk-zbd Then, add the following options to the QEMU command line: -blockdev node-name=drive0,driver=zoned_host_device,filename=/dev/nullb0 After the guest os booting, use blkzone(8) to test zone operations: blkzone report -o offset -c nr_zones /dev/vda v5: - add zoned storage emulation to virtio-blk device - add documentation for zoned storage - address review comments * fix qemu-iotests * fix check to block layer * modify interfaces of sysfs helper functions * rename zoned device structs according to QEMU styles * reorder patches v4: - add virtio-blk headers for zoned device - add configurations for zoned host device - add zone operations for raw-format - address review comments * fix memory leak bug in zone_report * add checks to block layers * fix qemu-iotests format * fix sysfs helper functions v3: - add helper functions to get sysfs attributes - address review comments * fix zone report bugs * fix the qemu-io code path * use thread pool to avoid blocking ioctl() calls v2: - add qemu-io sub-commands - address review comments * modify interfaces of APIs v1: - add block layer APIs resembling Linux ZoneBlockDevice ioctls Sam Li (11): include: add zoned device structs include: import virtio_blk headers from linux with zoned storage support file-posix: introduce get_sysfs_long_val for the long sysfs attribute file-posix: introduce get_sysfs_str_val for device zoned model block: add block layer APIs resembling Linux ZonedBlockDevice ioctls raw-format: add zone operations to pass through requests config: add check to block layer virtio-blk: add zoned storage APIs for zoned devices qemu-io: add zoned block device operations. qemu-iotests: test new zone operations docs/zoned-storage: add zoned device documentation block.c | 13 + block/block-backend.c | 139 +++++++ block/coroutines.h | 6 + block/file-posix.c | 383 +++++++++++++++++++- block/io.c | 41 +++ block/raw-format.c | 14 + docs/devel/zoned-storage.rst | 68 ++++ docs/system/qemu-block-drivers.rst.inc | 6 + hw/block/virtio-blk.c | 172 ++++++++- include/block/block-common.h | 44 ++- include/block/block-io.h | 13 + include/block/block_int-common.h | 35 +- include/block/raw-aio.h | 6 +- include/standard-headers/linux/virtio_blk.h | 118 ++++++ include/sysemu/block-backend-io.h | 6 + meson.build | 1 + qapi/block-core.json | 7 +- qemu-io-cmds.c | 144 ++++++++ tests/qemu-iotests/tests/zoned.out | 53 +++ tests/qemu-iotests/tests/zoned.sh | 86 +++++ 20 files changed, 1340 insertions(+), 15 deletions(-) create mode 100644 docs/devel/zoned-storage.rst create mode 100644 tests/qemu-iotests/tests/zoned.out create mode 100755 tests/qemu-iotests/tests/zoned.sh -- 2.37.1