On Tue, 20 Sept 2022 at 03:43, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Sun, Sep 18, 2022 at 10:29:18PM -0400, Dmitry Fomichev wrote: > > 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. > > What is the advantage in extending virtio-blk vs just using virtio-scsi > or nvme with shadow doorbells that just work? virtio-blk is widely used and new request types are added as needed. QEMU's NVMe emulation may support passing through zoned storage devices in the future but it doesn't today. Support was implemented in virtio-blk first because NVMe emulation isn't widely used in production QEMU VMs. Stefan
