Re: [PATCH 1/4] target/ppc: drop ppc_tlb_invalidate_all from cpu_reset

["Nicholas Piggin" <npiggin@gmail.com>]

On Wed Feb 26, 2025 at 4:46 AM AEST, Alex Bennée wrote:
> The vCPU parent already triggers a tb_flush so this is un-needed:
>
>   #0  tlb_flush_other_cpu (cpu=0x555556df8630) at ../../accel/tcg/cputlb.c:419
>   #1  0x0000555555ee38c9 in tcg_cpu_reset_hold (cpu=0x555556df8630) at ../../accel/tcg/tcg-accel-ops.c:88
>   #2  0x0000555555bc29e5 in cpu_exec_reset_hold (cpu=0x555556df8630) at ../../system/cpus.c:208
>   #3  0x00005555558932c3 in cpu_common_reset_hold (obj=0x555556df8630, type=RESET_TYPE_COLD) at ../../hw/core/cpu-common.c:139
>   #4  0x0000555555d480b1 in ppc_cpu_reset_hold (obj=0x555556df8630, type=RESET_TYPE_COLD) at ../../target/ppc/cpu_init.c:7200
>   #5  0x0000555555ef28f0 in resettable_phase_hold (obj=0x555556df8630, opaque=0x0, type=RESET_TYPE_COLD) at ../../hw/core/resettable.c:162
>   #6  0x0000555555ef24f4 in resettable_assert_reset (obj=0x555556df8630, type=RESET_TYPE_COLD) at ../../hw/core/resettable.c:58
>   #7  0x0000555555ef244c in resettable_reset (obj=0x555556df8630, type=RESET_TYPE_COLD) at ../../hw/core/resettable.c:45
>   #8  0x0000555555eef525 in device_cold_reset (dev=0x555556df8630) at ../../hw/core/qdev.c:239
>   #9  0x00005555558931ab in cpu_reset (cpu=0x555556df8630) at ../../hw/core/cpu-common.c:114
>   #10 0x0000555555d1ec6b in ppce500_cpu_reset (opaque=0x555556df8630) at ../../hw/ppc/e500.c:785
>   #11 0x000055555595c410 in legacy_reset_hold (obj=0x555556e6bbc0, type=RESET_TYPE_COLD) at ../../hw/core/reset.c:76
>   #12 0x0000555555ef28f0 in resettable_phase_hold (obj=0x555556e6bbc0, opaque=0x0, type=RESET_TYPE_COLD) at ../../hw/core/resettable.c:162
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>  target/ppc/cpu_init.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
> index 062a6e85fb..f987b75c4f 100644
> --- a/target/ppc/cpu_init.c
> +++ b/target/ppc/cpu_init.c
> @@ -7242,9 +7242,6 @@ static void ppc_cpu_reset_hold(Object *obj, ResetType type)
>      if (tcg_enabled()) {
>          cpu_breakpoint_remove_all(cs, BP_CPU);
>          cpu_watchpoint_remove_all(cs, BP_CPU);
> -        if (env->mmu_model != POWERPC_MMU_REAL) {
> -            ppc_tlb_invalidate_all(env);
> -        }

This invalidates architectural TLBs (software-loaded TLBs) as well, so I 
don't think we can get rid of it.

Thanks,
Nick