On Tue, Jul 15, 2014 at 12:20 AM, Paolo Bonzini <pbonz...@redhat.com> wrote: > Il 14/07/2014 14:36, Peter Crosthwaite ha scritto: > >> On Thu, Jun 26, 2014 at 5:32 PM, Markus Armbruster <arm...@redhat.com> >> wrote: >>> >>> Paolo Bonzini <pbonz...@redhat.com> writes: >>> >>>> Otherwise, hot-unplug of pci-serial-2x trips the assertion >>>> in memory_region_destroy: >>>> >>>> (qemu) device_del gg >>>> (qemu) qemu-system-x86_64: /work/armbru/tmp/qemu/memory.c:1021: >>>> memory_region_destroy: Assertion `((&mr->subregions)->tqh_first == ((void >>>> *)0))' failed. >>>> Aborted (core dumped) >>>> >>>> Reported-by: Markus Armbruster <arm...@redhat.com> >>>> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> >>> >>> >>> Reviewed-by: Markus Armbruster <arm...@redhat.com> >>> >> >> Reviewed-by: Peter Crosthwaite <peter.crosthwa...@xilinx.com> >> >>> Would it make sense to add a "must not contain subregions" to >>> memory_region_destroy()'s function comment? >>> >> >> Any reason to just not patch the memory region finaliser to unparent > > > Note that unparent for memory regions is _not_ memory_region_del_subregion. > It is memory_region_destroy. >
Yes, bad choice of words by me. What I was going for was "un-contain" I guess. Regards, Peter > The parent object of a memory region is a device; the _container_ of a > memory region is another memory region. > > >> all contained subregions automatically rather than assert? Destroying >> a container should imply removing the subregion relationship and >> simply orphan the subregion. > > > This makes sense since we will soon make memory_region_destroy optional > (devices will automatically destroy their memory regions). Before > QOMification, however, I think the assert was a useful debugging tool, > guaranteeing that owners of memory regions were destroyed in the right > order. So we could indeed revisit this in 2.2 and make > memory_region_del_subregion also optional. > > Paolo >
