Markus Armbruster <arm...@redhat.com> 于2023年11月3日周五 17:08写道：
>
> 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.
Yes, it should use a QMP union. It's better to separate those fields
for zoned and non-zoned.
>
> >> +#
> >> +# @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.
>
Yes, it's better. Thanks!
Sam
