Re: [Qemu-devel] [PATCH 0/8] qom: introduce non-legacy static properties

[Anthony Liguori <anthony@codemonkey.ws>]

On 12/16/2011 06:01 AM, Paolo Bonzini wrote:
> QOM right now does not have a way to communicate values for qdev
> properties except as strings.  This is bad.
>
> This patch improves the Property implementation so that properties
> export a visitor-based interface in addition to the string-based
> interface.  The new interface can then be registered as a "static"
> property.  It's called static because it uses a struct field for
> storage and, as such, should be present in all objects of a given
> class.

Excellent!  See the patches for individual comments but this is definitely a 
good thing to have.

Regards,

Anthony Liguori

>
> Patches 1-3 are bugfixes and patch 4 is a cleanup, so please apply
> those at least.
>
> Example using qmp-shell:
>
> x86_64-softmmu/qemu-system-x86_64 \
>     -hda ~/test.img -snapshot -S \
>     -qmp unix:/tmp/server.sock,server,nowait \
>     -netdev type=user,id=net -device virtio-net-pci,netdev=net,id=net \
>     -net user,vlan=1 -device virtio-net-pci,id=net2,vlan=1 \
>     -chardev id=stdio,backend=stdio -device isa-serial,chardev=stdio,id=serial
>
> Boolean properties:
>
> (QEMU) qom-get path=/i440fx/piix3 property=command_serr_enable
> {u'return': True}
> (QEMU) qom-get path=/i440fx/piix3 property=legacy<command_serr_enable>
> {u'return': u'on'}
>
> PCI address properties (perhaps will disappear later, but not yet):
>
> (QEMU) qom-get path=/i440fx/piix3 property=addr
> {u'return': u'01.0'}
> (QEMU) qom-get path=/i440fx/piix3 property=legacy<addr>
> {u'return': u'01.0'}
>
> String properties (QObject does not have NULL):
>
> (QEMU) qom-get path=/vga property=romfile
> {u'return': u'vgabios-cirrus.bin'}
> (QEMU) qom-get path=/vga property=legacy<romfile>
> {u'return': u'"vgabios-cirrus.bin"'}
> (QEMU) qom-get path=/i440fx/piix3 property=romfile
> {u'return': {}}
> (QEMU) qom-get path=/i440fx/piix3 property=legacy<romfile>
> {u'return': u'<null>'}
>
> MAC properties:
>
> (QEMU) qom-get path=/peripheral/net property=mac
> {u'return': u'52:54:00:12:34:56'}
> (QEMU) qom-get path=/peripheral/net property=legacy<mac>
> {u'return': u'52:54:00:12:34:56'}
> (QEMU) qom-set path=/peripheral/net property=mac value=52-54-00-12-34-57
> {u'error': {u'data': {}, u'class': u'PermissionDenied', u'desc': u'Insufficient permission to perform this operation'}}
>
> Network properties:
>
> (QEMU) qom-get path=/peripheral/net property=netdev
> {u'return': u'net'}
> (QEMU) qom-get path=/peripheral/net property=legacy<netdev>
> {u'return': u'net'}
>
> VLAN properties:
>
> (QEMU) qom-get path=/peripheral/net property=vlan
> {u'return': {}}
> (QEMU) qom-get path=/peripheral/net property=legacy<vlan>
> {u'return': u'<null>'}
> (QEMU) qom-get path=/peripheral/net2 property=vlan
> {u'return': 1}
> (QEMU) qom-get path=/peripheral/net2 property=legacy<vlan>
> {u'return': u'1'}
>
> Chardev properties:
>
> (QEMU) qom-get path=/peripheral/serial property=chardev
> {u'return': u'stdio'}
> (QEMU) qom-get path=/peripheral/serial property=legacy<chardev>
> {u'return': u'stdio'}
>
> Legacy hex32 properties:
>
> (QEMU) qom-get path=/peripheral/serial property=iobase
> {u'return': 1016}
> (QEMU) qom-get path=/peripheral/serial property=legacy<iobase>
> {u'return': u'0x3f8'}
>
> Examples of setting properties (after disabling the DEV_STATE_CREATED
> check for testing only):
>
> (QEMU) qom-set path=/peripheral/net2 property=vlan value=-1
> {u'return': {}}
> (QEMU) qom-get path=/peripheral/net2 property=vlan
> {u'return': {}}
> (QEMU) qom-get path=/peripheral/net2 property=legacy<vlan>
> {u'return': u'<null>'}
>
> (QEMU) qom-set path=/peripheral/serial property=iobase value=760
> {u'return': {}}
> (QEMU) qom-get path=/peripheral/serial property=iobase
> {u'return': 760}
> (QEMU) qom-get path=/peripheral/serial property=legacy<iobase>
> {u'return': u'0x2f8'}
>
> Paolo Bonzini (8):
>    qapi: fix NULL pointer dereference
>    qapi: protect against NULL QObject in qmp_input_get_object
>    qom: fix swapped parameters
>    qom: push permission checks up into qdev_property_add_legacy
>    qom: introduce QERR_PROPERTY_VALUE_OUT_OF_RANGE
>    qom: introduce get/set methods for Property
>    qom: distinguish "legacy" property type name from QOM type name
>    qom: register qdev properties also as non-legacy properties
>
>   hw/qdev-addr.c            |   41 +++++
>   hw/qdev-properties.c      |  360 ++++++++++++++++++++++++++++++++++++++++++++-
>   hw/qdev.c                 |   85 +++++++-----
>   hw/qdev.h                 |   12 +-
>   qapi/qmp-input-visitor.c  |   10 +-
>   qapi/qmp-output-visitor.c |    4 +-
>   qerror.c                  |    5 +
>   qerror.h                  |    3 +
>   8 files changed, 472 insertions(+), 48 deletions(-)
>