Re: [PATCH v4 07/13] accel-ops: Introduce create_vcpu_thread_precheck / postcheck handlers

[Richard Henderson]

On 3/23/22 10:17, Philippe Mathieu-Daudé wrote:
> From: Philippe Mathieu-Daudé <f4bug@amsat.org>
>
> Introduce precheck/postcheck handlers which will help to
> refactor code common to the various create_vcpu_thread()
> implementations.
>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>   include/sysemu/accel-ops.h | 4 ++++
>   softmmu/cpus.c             | 8 +++++++-
>   2 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
> index 6013c9444c..26b542d35c 100644
> --- a/include/sysemu/accel-ops.h
> +++ b/include/sysemu/accel-ops.h
> @@ -31,6 +31,10 @@ struct AccelOpsClass {
>       bool (*cpus_are_resettable)(void);
>   
>       void (*create_vcpu_thread)(CPUState *cpu); /* MANDATORY NON-NULL */
> +    /* If non-NULL, return whether common vCPU thread must be created */
> +    bool (*create_vcpu_thread_precheck)(CPUState *cpu);
> +    void (*create_vcpu_thread_postcheck)(CPUState *cpu);


I don't think this is the correct trade-off.
These new hooks are only used by rr, and at least in this patch set, 
incorrectly.

I think you should keep the single create_vcpu_thread hook, and if null, use your new 
common_vcpu_thread_create.  Leave rr to be the single accel setting the hook, and then 
it's easier not to break rr during the reorg as well.


r~