Re: [Qemu-devel] [RFC PATCH v4 00/44] Support Kconfig in QEMU

[BALATON Zoltan]

On Thu, 24 Jan 2019, Paolo Bonzini wrote:
> On 23/01/19 07:55, Yang Zhong wrote:
> > This Kconfig implementation is rebased from Paolo's branch
> > https://github.com/bonzini/qemu/commits/kconfig
> >
> > I rebased most of patches except non-x86 ARCHs dependency definitions
> > this time.
> > https://github.com/yangzhon/qemu/commits/topic/upstream/Kconfig
> >
> > The current RFC patches only support
> > (*) x86_64 platform build
> >     Once design is fixed, we can do other archs.
> >
> > (*) defconfig
> >     "randconfig" build has some issues, which are mostly related
> >     with CONFIG* in Kconfig.host abd configure. In randconfig mode,
> >     some CONFIG* has different setting value in config-host.mak and
> >     %/config-device.mak, which make QEMU build failure.
> >
> > (*) Kconfig in hw/ directory
> >
> > The current configure and build command are same with previous
> > commands and if we want to disable or enable some features, like
> > "tcg", we still need add "--enable/--disable-tcg" in configure
> > command line. If we want to disable one emulation device, we can
> > disable this in related Kconfig file in hw/ directory.
> >
> > The current build command:
> > (*) ./configure --target-list=x86_64-softmmu
> > (*) make -j8
> >
> > Since the Kconfig language replace traditional CONFIG_* in
> > default-config/%-softmmu.mak, the %-softmmu.mak file only
> > define embeded boards or machines, like 440fx and Q35 in x86_64
> > platform. The Kconfig has already defined dependency topology
> > between different Kconfig files, but there are still some issues
> >
> > (*) Kconfig for configure(config-host.mak)
> >     Some CONFIG* in configure  need some logic to generate, those
> >     are hard to input this CONFIG* in Kconfig.host or Kconfig* file.
> >
> > (*) Kconfig for %config-target.mak
> >     The CONFIG* in %/config-target.mak file, this is still related
> >     with configure.
> >
> > (*) randconfig support issue.
> >
> > Before this RFC patches, we have talked Kconfig in another thread
> > http://lists.nongnu.org/archive/html/qemu-devel/2018-09/msg02827.html
> >
> > Please give your comments on this RFC thread, many thanks!
>
> I started looking at this, and found two bugs in current code
> (unreachable devices that shouldn't be there - SERIAL_ISA for ARM,
> ACPI_NVDIMM for MIPS).  There are a few issues in that the script is not

The ACPI_NVDIMM for MIPS is pulled in by CONFIG_VT82C686 which needs ACPI 
which needs NVDIMM even though it's probably not used. At least I think 
so, I haven't tested if it could be removed.

Regards,
BALATON Zoltan

> Python 3-enabled and only x86 compiles, but they are easily fixed.  A
> slightly bigger thing is to make VFIO configuration more fine-grained
> and express it with kconfig dependencies, but it's just a couple patches
> in the same spirit as these ones.  I'll look at randconfig next.
>
> Paolo