Eric Blake <ebl...@redhat.com> writes:
> On Mon, Oct 30, 2023 at 08:18:45PM +0800, Sam Li wrote:
>> To configure the zoned format feature on the qcow2 driver, it
>> requires settings as: the device size, zone model, zone size,
>> zone capacity, number of conventional zones, limits on zone
>> resources (max append bytes, max open zones, and max_active_zones).
>>
>> To create a qcow2 file with zoned format, use command like this:
>> $ qemu-img create -f qcow2 test.qcow2 -o size=768M -o
>> zone_size=64M -o zone_capacity=64M -o conventional_zones=0 -o
>> max_append_bytes=4096 -o max_open_zones=0 -o max_active_zones=0
>> -o zone_model=host-managed
>>
>> Signed-off-by: Sam Li <faithilike...@gmail.com>
>>
>> fix config?
>
> Is this comment supposed to be part of the commit message? If not,...
>
>> ---
>
> ...place it here under the divider, so 'git am' won't include it, if there is
> nothing further to change on this patch.
[...]
>> +++ b/qapi/block-core.json
>> @@ -4981,6 +4981,21 @@
>> { 'enum': 'Qcow2CompressionType',
>> 'data': [ 'zlib', { 'name': 'zstd', 'if': 'CONFIG_ZSTD' } ] }
>>
>> +##
>> +# @Qcow2ZoneModel:
>> +#
>> +# Zoned device model used in qcow2 image file
>> +#
>> +# @non-zoned: non-zoned model is for regular block devices
>> +#
>> +# @host-managed: host-managed model only allows sequential write over the
>> +# device zones
>> +#
>> +# Since 8.2
>> +##
>> +{ 'enum': 'Qcow2ZoneModel',
>> + 'data': ['non-zoned', 'host-managed'] }
>> +
>> ##
>> # @BlockdevCreateOptionsQcow2:
>> #
>> @@ -5023,6 +5038,27 @@
>> # @compression-type: The image cluster compression method
>> # (default: zlib, since 5.1)
>> #
>> +# @zone-model: @Qcow2ZoneModel. The zone device model.
>> +# (default: non-zoned, since 8.2)
>> +#
>> +# @zone-size: Total number of bytes within zones (since 8.2)
>
> If @zone-model is "non-zoned", does it make sense to even allow
> @zone-size and friends? Should this use a QMP union, where you can
> pass in the remaining zone-* fields only when zone-model is set to
> host-managed?
Valid question; needs an answer.
>> +#
>> +# @zone-capacity: The number of usable logical blocks within zones
>> +# in bytes. A zone capacity is always smaller or equal to the
>> +# zone size (since 8.2)
>> +#
>> +# @conventional-zones: The number of conventional zones of the
>> +# zoned device (since 8.2)
>> +#
>> +# @max-open-zones: The maximal number of open zones (since 8.2)
>> +#
>> +# @max-active-zones: The maximal number of zones in the implicit
>> +# open, explicit open or closed state (since 8.2)
>> +#
>> +# @max-append-bytes: The maximal number of bytes of a zone
>> +# append request that can be issued to the device. It must be
>> +# 512-byte aligned (since 8.2)
>> +#
>> # Since: 2.12
>> ##
>> { 'struct': 'BlockdevCreateOptionsQcow2',
>> @@ -5039,7 +5075,14 @@
>> '*preallocation': 'PreallocMode',
>> '*lazy-refcounts': 'bool',
>> '*refcount-bits': 'int',
>> - '*compression-type':'Qcow2CompressionType' } }
>> + '*compression-type':'Qcow2CompressionType',
>> + '*zone-model': 'Qcow2ZoneModel',
>> + '*zone-size': 'size',
>> + '*zone-capacity': 'size',
>> + '*conventional-zones': 'uint32',
>> + '*max-open-zones': 'uint32',
>> + '*max-active-zones': 'uint32',
>> + '*max-append-bytes': 'uint32' } }
>
> In other words, I'm envisioning something like an optional
> '*zone':'ZoneStruct', where:
>
> { 'struct': 'ZoneHostManaged',
> 'data': { 'size': 'size', '*capacity': 'size', ..., '*max-append-bytes':
> 'uint32' } }
> { 'union': 'ZoneStruct',
> 'base': { 'model': 'Qcow2ZoneModel' },
> 'discriminator': 'model',
> 'data': { 'non-zoned': {},
> 'host-managed': 'ZoneHostManaged' } }
>
> then over the wire, QMP can use the existing:
> { ..., "compression-type":"zstd" }
>
> as a synonym for the new but explicit non-zoned:
> { ..., "compression-type":"zstd", "zone":{"mode":"non-zoned"} }
I.e. @zone is optional, and defaults to {"mode": "non-zoned"}.
> and when we want to use zones, we pass:
> { ..., "compression-type":"zstd", "zone":{"mode":"host-managed",
> "size":16777216} }
>
> where you don't have to have zone- prefixing everywhere because it is
> instead contained in the smart union object where it is obvious from
> the 'mode' field what other fields should be present.
