[Qemu-devel] [PATCH v3 0/8] qom: introduce non-legacy static properties

[Paolo Bonzini <pbonzini@redhat.com>]

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.

Patches 1-2 are bugfixes and patches 3-4 are cleanups.

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 (NULL mapped to empty string):

(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': u''}
(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': -1}
(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': -1}
(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'}

v2->v3:
	Tweaks to patch 4.

v1->v2:
        New "qom: interpret the return value when setting legacy
        properties".  Always pass a value to the visitor when there
        is no error.  Handle empty strings as NULL.  Did not change
        QERR_PROPERTY_VALUE_OUT_OF_RANGE because it is consistent
        with other QERR_PROPERTY_* errors, now used by QOM too.

Paolo Bonzini (8):
  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: interpret the return value when setting legacy properties
  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     |  407 +++++++++++++++++++++++++++++++++++++++++++--
 hw/qdev.c                |   84 ++++++----
 hw/qdev.h                |   14 +-
 qapi/qmp-input-visitor.c |   10 +-
 qerror.c                 |    5 +
 qerror.h                 |    3 +
 7 files changed, 502 insertions(+), 62 deletions(-)

-- 
1.7.7.1