Il 03/12/2013 15:35, Andreas Färber ha scritto: > Am 03.12.2013 15:00, schrieb Paolo Bonzini: >> Il 03/12/2013 14:44, Andreas Färber ha scritto: >>>>> >>>>> You can check "if (current_machine && >>>>> current_machine->get_fw_dev_path)", and move current_machine from vl.c >>>>> to hw/qdev/core.c. >>> Please don't encourage moving random stuff into "core" device code. >>> >>> If needed, we can easily add a machine.c, but that should remain >>> softmmu-only. >> >> Another solution would be to: >> >> (1) add an interface which contains "get_fw_dev_path". When >> qdev_get_fw_dev_path is called, walk the QOM tree until an object that >> implements the interface is found. If none is found, call the bus >> implementation as usual. >> >> (2) in vl.c, add a way for current_machine to override the /machine >> object. A 100%-QOMified machine indeed could put a SOC-like Device there. >> >> (3) for spapr, define the machine object to something that implements >> said interface. >> >> It seemed a bit complicated for this particular problem, but I cannot >> say it's overengineered. >> >> More aspects of the configuration could be moved to the new interface >> over time, for example compat properties. > > I remember Hervé running into problems with interfaces and ppc -cpu ? > (or -cpu host?), which does an object_class_foreach(), in the middle of > which QOM interfaces tried registering new types, leading to a GLib > assertion. Anthony never replied to that patch despite repeated pings, > so the issue is likely still unresolved. > > http://patchwork.ozlabs.org/patch/241072/ (proposed workaround) > http://patchwork.ozlabs.org/patch/241504/ (test case) > http://patchwork.ozlabs.org/patch/241073/ (actual interface attempt)
Well, let's fix it. Thanks for the test case. > They are also kind of odd wrt memory management since even when we > object_initialize() previously allocated memory, interfaces of that type > are not part of the object size and are still dynamically allocated > IIRC. That may well be fixable of course by allocating space for > interfaces after the instance_size and bumping its copy in > TypeImpl::instance_size accordingly or calculate it in my proposed > type_get_instance_size(). > http://patchwork.ozlabs.org/patch/269591/ > http://patchwork.ozlabs.org/patch/269595/ No, that has changed since commit 33e95c6 (qom: Reimplement Interfaces, 2012-08-10). Paolo
