[PATCH v7 1/4] docs/qcow2: add the zoned format feature

Sam Li posted 4 patches 4 months ago
Maintainers: Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>
[PATCH v7 1/4] docs/qcow2: add the zoned format feature
Posted by Sam Li 4 months ago
Add the specs for the zoned format feature of the qcow2 driver.
The qcow2 file then can emulate real zoned devices, either passed
through by virtio-blk device or NVMe ZNS drive to the guest
given zoned information.

Signed-off-by: Sam Li <faithilikerun@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 docs/system/qemu-block-drivers.rst.inc | 42 ++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/docs/system/qemu-block-drivers.rst.inc b/docs/system/qemu-block-drivers.rst.inc
index 105cb9679c..4db19b61ae 100644
--- a/docs/system/qemu-block-drivers.rst.inc
+++ b/docs/system/qemu-block-drivers.rst.inc
@@ -172,6 +172,48 @@ This section describes each format and the options that are supported for it.
     filename`` to check if the NOCOW flag is set or not (Capital 'C' is
     NOCOW flag).
 
+  .. option:: zone.mode
+    If this is set to ``host-managed``, the image is an emulated zoned
+    block device. This option is only valid to emulated zoned device files.
+
+  .. option:: zone.size
+
+    The size of a zone in bytes. The device is divided into zones of this
+    size with the exception of the last zone, which may be smaller.
+
+  .. option:: zone.capacity
+
+    The initial capacity value, in bytes, for all zones. The capacity must
+    be less than or equal to zone size. If the last zone is smaller, then
+    its capacity is capped.
+
+    The zone capacity is per zone and may be different between zones in real
+    devices. QCow2 sets all zones to the same capacity.
+
+  .. option:: zone.conventional_zones
+
+    The number of conventional zones of the zoned device.
+
+  .. option:: zone.max_active_zones
+
+    The limit of the zones with implicit open, explicit open or closed state.
+
+    The max active zones must be less or equal to the number of SWR
+    (sequential write required) zones of the device.
+
+  .. option:: zone.max_open_zones
+
+    The maximal allowed open zones. The max open zones must not be larger than
+    the max active zones.
+
+    If the limits of open zones or active zones are equal to the number of
+    SWR zones, then it is the same as having no limits.
+
+  .. option:: zone.max_append_bytes
+
+    The number of bytes in a zone append request that can be issued to the
+    device. It must be 512-byte aligned and less than the zone capacity.
+
 .. program:: image-formats
 .. option:: qed
 
-- 
2.40.1