Re: [RFC v4 0/9] Add support for zoned device

[Stefan Hajnoczi <stefanha@gmail.com>]

This patch series introduces the concept of zoned storage to the QEMU
block layer. Documentation is needed so that users and developers know
how to use and maintain this feature.

As a minimum, let's document how to pass through zoned block devices on Linux:

diff --git a/docs/system/qemu-block-drivers.rst.inc
b/docs/system/qemu-block-drivers.rst.inc
index dfe5d2293d..f6ba05710a 100644
--- a/docs/system/qemu-block-drivers.rst.inc
+++ b/docs/system/qemu-block-drivers.rst.inc
@@ -430,6 +430,12 @@ Hard disks
   you may corrupt your host data (use the ``-snapshot`` command
   line option or modify the device permissions accordingly).

+Zoned block devices
+  Zoned block devices can be passed through to the guest if the emulated
+  storage controller supports zoned storage. Use ``--blockdev
+  zoned_host_device,node-name=drive0,filename=/dev/nullb0`` to pass through
+  ``/dev/nullb0`` as ``drive0``.
+
 Windows
 ^^^^^^^

For developers there should be an explanation of the zoned storage
APIs and how BlockDrivers declare support. It should also mention the
status of pass through (implemented in the zoned_host_device driver)
vs zone emulation (not implemented in the QEMU block layer) so
developers understand the block layer's zoned storage capabilities.
You can add a docs/devel/zoned-storage.rst file to document this or
let me know if you want me to write it.

Stefan