Peter Maydell <peter.mayd...@linaro.org> writes: > On 5 April 2013 17:47, Anthony Liguori <anth...@codemonkey.ws> wrote: >> Kevin Wolf <kw...@redhat.com> writes: >> >>> From: KONRAD Frederic <fred.kon...@greensocs.com> >>> >>> The virtio-blk-x configuration is not in sync with virtio-blk configuration. >>> So this patch remove the virtio-blk-x configuration field, and use >>> virtio-blk >>> one for setting the properties. >>> >>> This also remove a useless configuration copy in virtio_blk_device_init. >>> >>> Signed-off-by: KONRAD Frederic <fred.kon...@greensocs.com> >>> Tested-by: Cornelia Huck <cornelia.h...@de.ibm.com> >>> Signed-off-by: Kevin Wolf <kw...@redhat.com> >> >> This breaks -M pc-1.0 as it breaks global properties. > > The first level analysis of why this happens: > > (1) global values are set as part of DeviceState's instance_init function > [and we set the config_wce field to 0 here] > (2) virtio_blk_pci_instance_init is a subclass instance_init so runs second > (3) it calls object_initialize on its embedded virtio-blk object > (4) the DeviceState instance_init for that child object sets the > properties to their init values [thus resetting config_wce to 1] > > The effect is that at the moment you can't have a property on > a parent object whose value is stored in the child object > (unless you do something hacky like read the default before > calling object_initialize and restore it afterwards]. > > It seems to me that the underlying problem here is that we > set global values too early -- they should be set after a > device is completely instance_init'd, not halfway through init.
Here is an in-progress series that forwards properties from the virtio-blk-pci to virtio-blk. I think it's the best solution. The approach needs some polishing but I wanted to share early. https://github.com/aliguori/qemu/commits/qom-forward.1 Regards, Anthony Liguori > > -- PMM
