Re: [Qemu-devel] hw/Makefile.objs question

["Andreas Färber" <afaerber@suse.de>]

Am 21.06.2012 13:21, schrieb Alexey Kardashevskiy:
> On 21/06/12 20:36, Andreas Färber wrote:
>> Am 21.06.2012 05:22, schrieb Alexey Kardashevskiy:
>>> I am trying to compile the very last qemu with vfio_pci enabled. VFIO_PCI is added as below:
>>>
>>> ./configure:
>>>
>>>  case "$target_arch2" in
>>>   i386|x86_64|ppc64)
>>>      if test "$vfio_pci" = "yes" -a "$target_softmmu" = "yes" ; then
>>>        echo "CONFIG_VFIO_PCI=y" >> $config_target_mak
>>>      fi
>>>  esac
>>>
>>>
>>> ./Makefile.target:
>>>
>>>  # VFIO PCI device assignment
>>> obj-$(CONFIG_VFIO_PCI) += vfio_pci.o
>>>
>>>
>>> And it worked before. However it does not anymore as it seems that everything in hw/ (and vfio_pci.c
>>> as well as is in hw/ and it is a device) can be only compiled via hw/Makefile.objs and
>>> hw/ppc/Makefile.objs (my platform is POWER), it is ignored if to keep it as is.
>>>
>>> So I have to move "obj-$(CONFIG_VFIO_PCI) += vfio_pci.o" to hw/Makefile.objs (and change obj- to
>>> hw-obj-) but the hw/Makefile.objs does not include (directly or indirectly) generated
>>> ppc64-softmmu/config-target.mak with CONFIG_VFIO_PCI=y.
>>>
>>> What is the correct solution?
>>
>> If the file compiles the same for all three, put CONFIG_VFIO_PCI=y into
>> default-configs/{i386,x86_64,ppc64}-softmmu.mak and do
>> hw-obj-$(CONFIG_VFIO_PCI) += in hw/Makefile.objs.
> 
> 
> It only compiles with ./configure --enable-vfio-pci which may or may not set CONFIG_VFIO_PCI to "y".
> Your proposal makes it always "y" (for selected platforms).

Apply some creativity, there's surely examples around. The question is
whether the contents of vfio_pci.o changes or not. If not, then you only
need to build it once in libhwX/, depending on $config_target_mak, and
link to the appropriate targets. If it accesses CPU internals then it
must be built per target.

>> Otherwise, add to hw/{i386,ppc}/Makefile.objs - or with Anthony's
>> proposal from yesterday hw/Makefile.objs becomes possible, too.
> 
> Again, it will be unconditional "y".

No, in this case the condition would be set from configure as before, it
only moves from Makefile.target to the appropriate Makefile.objs.
Note that to limit it to ppc64 (as opposed to ppc) some additional ifeq
check would be needed, as before.

Andreas

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