Re: [PATCH v2 21/54] accel/tcg: Delay plugin adjustment in probe_access_internal

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 11/14/24 08:00, Richard Henderson wrote:
> Remove force_mmio and place the expression into the IF
> expression, behind the short-circuit logic expressions
> that might eliminate its computation.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   accel/tcg/cputlb.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c
> index 3e24529f4f..a4c69bcbf1 100644
> --- a/accel/tcg/cputlb.c
> +++ b/accel/tcg/cputlb.c
> @@ -1373,7 +1373,6 @@ static int probe_access_internal(CPUState *cpu, vaddr addr,
>       CPUTLBEntry *entry = tlb_entry(cpu, mmu_idx, addr);
>       uint64_t tlb_addr = tlb_read_idx(entry, access_type);
>       int flags = TLB_FLAGS_MASK & ~TLB_FORCE_SLOW;
> -    bool force_mmio = check_mem_cbs && cpu_plugin_mem_cbs_enabled(cpu);
>       CPUTLBEntryFull *full;
>   
>       if (!tlb_hit(tlb_addr, addr)) {
> @@ -1404,9 +1403,14 @@ static int probe_access_internal(CPUState *cpu, vaddr addr,
>       *pfull = full = &cpu->neg.tlb.d[mmu_idx].fulltlb[index];
>       flags |= full->slow_flags[access_type];
>   
> -    /* Fold all "mmio-like" bits into TLB_MMIO.  This is not RAM.  */
> -    if (unlikely(flags & ~(TLB_WATCHPOINT | TLB_NOTDIRTY | TLB_CHECK_ALIGNED))
> -        || (access_type != MMU_INST_FETCH && force_mmio)) {
> +    /*
> +     * Fold all "mmio-like" bits, and required plugin callbacks, to TLB_MMIO.
> +     * These cannot be treated as RAM.
> +     */
> +    if ((flags & ~(TLB_WATCHPOINT | TLB_NOTDIRTY | TLB_CHECK_ALIGNED))
> +        || (access_type != MMU_INST_FETCH
> +            && check_mem_cbs
> +            && cpu_plugin_mem_cbs_enabled(cpu))) {
>           *phost = NULL;
>           return TLB_MMIO;
>       }

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>