Re: [RFC PATCH 16/40] target/arm: Represent the entire MPIDR_EL1

[Peter Maydell]

On Tue, 3 Jan 2023 at 18:24, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> Replace ARMCPU.mp_affinity with CPUARMState.cp15.mpidr_el1,
> setting the additional bits as required.  In particular,
> always set the U bit when there is only one cpu in the system.
> Remove the mp_is_up bit which attempted to do the same thing.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/cpu.h     |  7 ++--
>  target/arm/cpu.c     | 80 +++++++++++++++++++++++++++++++++++++-------
>  target/arm/cpu_tcg.c |  1 -
>  target/arm/helper.c  | 25 ++------------
>  target/arm/hvf/hvf.c |  2 +-
>  target/arm/kvm64.c   |  4 +--
>  6 files changed, 75 insertions(+), 44 deletions(-)

Based purely on the diffstat it's not super-obvious why this
is an improvement. What's the rationale ?

Side note, we don't currently handle the MT bit, where some
CPUs end up putting the cpu number in the Aff1 field rather
than Aff0. We ideally ought to handle that too.

thanks
-- PMM