In its current form, the virtio protocol for block devices (virtio-blk) is not aware of zoned block devices (ZBDs) but it allows the driver to successfully scan a host-managed drive provided by the virtio block device. As the result, the host-managed drive is recognized by the virtio driver as a regular, non-zoned drive that will operate erroneously under the most common write workloads. Host-aware ZBDs are currently usable, but their performance may not be optimal because the driver can only see them as non-zoned block devices. To fix this, the virtio-blk protocol needs to be extended to add the capabilities to convey the zone characteristics of ZBDs at the device side to the driver and to provide support for ZBD-specific commands - Report Zones, four zone operations (Open, Close, Finish and Reset) and (optionally) Zone Append. The required virtio-blk protocol extensions are currently under review at OASIS Technical Committee and the specification patch is linked at https://github.com/oasis-tcs/virtio-spec/issues/143 . The QEMU zoned device code that implements these protocol extensions has been developed by Sam Li, an intern, as a part of Outreachy community mentorship initiative. The latest version of the QEMU patchset can be found here: https://lists.gnu.org/archive/html/qemu-devel/2022-10/msg05195.html This patch series modifies the virtio block driver code to implement the above virtio specification extensions. This patch has been tested to be compatible with the QEMU implementation referred above. v2 -> v3: - Change the request in-header layout to always make the status byte the last byte of the in-header. For all requests except Zone Append, the in-header consists only of the status byte. For Zone Append, an extended in-header is defined that consists of the zone append sector followed by the status byte - In zone report handler, validate the zone type/condition values that are received from the device and convert them from the values defined in the virtio_blk ZBD spec extension to the values defined in the block layer - During ZBD scan, check that max_append_sectors value that is reported by the device is not smaller than the write granularity - Fix sparse warnings v1 -> v2: - Rebase to the current head of development. The second patch in the previous version is no longer needed as the secure erase support has now been added to virtio_blk driver - Fix a couple of bugs in zone report code - Clean up ZBD probe code This version DOESN'T include the additional request layout changes that are being discussed at the OASIS TC. An updated patch series will be posted to the list when those changes are finalized. Dmitry Fomichev (2): virtio-blk: use a helper to handle request queuing errors virtio-blk: add support for zoned block devices drivers/block/virtio_blk.c | 470 +++++++++++++++++++++++++++++--- include/uapi/linux/virtio_blk.h | 105 +++++++ 2 files changed, 543 insertions(+), 32 deletions(-) -- 2.34.1
