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

[Paolo Bonzini]

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
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