Re: [Qemu-devel] [PATCH for 2.10] tcg: enable MTTCG by default for PPC64 on x86

["Alex Bennée" <alex.bennee@linaro.org>]

Nikunj A Dadhania <nikunj@linux.vnet.ibm.com> writes:

> This enables the multi-threaded system emulation by default for PPC64
> guests using the x86_64 TCG back-end.

Technically this enables it for all backends that can meet the guests
default memory model requirements. So far only the x86 backend defines
one as:

  #define TCG_TARGET_DEFAULT_MO (TCG_MO_ALL & ~TCG_MO_ST_LD)

>
> Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

> ---
>
> Depends on following patch which fixes the define name:
>
> https://patchwork.ozlabs.org/patch/748840/
>
> ---
>  configure        | 2 ++
>  target/ppc/cpu.h | 2 ++
>  2 files changed, 4 insertions(+)
>
> diff --git a/configure b/configure
> index 4b3b5cd..2a87495 100755
> --- a/configure
> +++ b/configure
> @@ -6008,12 +6008,14 @@ case "$target_name" in
>    ppc64)
>      TARGET_BASE_ARCH=ppc
>      TARGET_ABI_DIR=ppc
> +    mttcg=yes
>      gdb_xml_files="power64-core.xml power-fpu.xml power-altivec.xml power-spe.xml power-vsx.xml"
>    ;;
>    ppc64le)
>      TARGET_ARCH=ppc64
>      TARGET_BASE_ARCH=ppc
>      TARGET_ABI_DIR=ppc
> +    mttcg=yes
>      gdb_xml_files="power64-core.xml power-fpu.xml power-altivec.xml power-spe.xml power-vsx.xml"
>    ;;
>    ppc64abi32)
> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
> index e0ff041..ece535d 100644
> --- a/target/ppc/cpu.h
> +++ b/target/ppc/cpu.h
> @@ -30,6 +30,8 @@
>  #define TARGET_LONG_BITS 64
>  #define TARGET_PAGE_BITS 12
>
> +#define TCG_GUEST_DEFAULT_MO 0
> +
>  /* Note that the official physical address space bits is 62-M where M
>     is implementation dependent.  I've not looked up M for the set of
>     cpus we emulate at the system level.  */


--
Alex Bennée