Re: [Qemu-devel] [PATCH 01/15] configure: add the disable-tcg option

[Richard Henderson]

On 06/21/2017 03:19 AM, Yang Zhong wrote:
> +case "$target_name" in
> +  
> alpha|arm|armeb|aarch64|cris|hppa|lm32|m68k|microblaze|microblazeel|mips|mipsel|
>  \
> +  
> mipsn32|mipsn32el|mips64|mips64el|moxie|nios2|or1k|ppc|ppcemb|ppc64|ppc64le|ppc64abi32|
>  \
> +  
> sh4|sh4eb|sparc|sparc64|sparc32plus|s390x|tilegx|tricore|unicore32|xtensa|xtensaeb)
> +  if test "$target_softmmu" = "yes" ; then
> +    echo "CONFIG_TCG=y" >> $config_target_mak
> +  fi
> +  ;;
> +esac
> +case "$target_name" in
> +  i386|x86_64)
> +  if test "$tcg" = "yes" -a "$target_softmmu" = "yes" ; then
> +    echo "CONFIG_TCG=y" >> $config_target_mak
> +  fi
> +  ;;
> +esac

This is definitely the wrong way around.  Test for the thing you want to 
special case -- x86, when running on x86, and softmmu -- and then everything 
else via *.

I strongly suspect this test should be

  case "$cpu-$target-$tcg" in
  x86_64-i386-softmmu-no | x86_64-x86_64-softmmu-no)
    # CONFIG_TCG disabled.
    ;;
  *)
    echo "CONFIG_TCG=y" >> $config_target_mak
  esac

This is easily extendable to allow TCG to be disabled for other KVM hosts.


r~