Re: [PATCH 22/22] accel/tcg: also suppress asynchronous IRQs for cpu_io_recompile

[Richard Henderson]

On 1/9/25 09:06, Alex Bennée wrote:
> While it would be technically correct to allow an IRQ to happen (as
> the offending instruction never really completed) it messes up
> instrumentation. We already take care to only use memory
> instrumentation on the block, we should also suppress IRQs.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> Cc: Richard Henderson <richard.henderson@linaro.org>
> Cc: Julian Ganz <neither@nut.email>
> ---
>   accel/tcg/translate-all.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~

> diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
> index 453eb20ec9..d56ca13cdd 100644
> --- a/accel/tcg/translate-all.c
> +++ b/accel/tcg/translate-all.c
> @@ -633,9 +633,10 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
>        * Exit the loop and potentially generate a new TB executing the
>        * just the I/O insns. We also limit instrumentation to memory
>        * operations only (which execute after completion) so we don't
> -     * double instrument the instruction.
> +     * double instrument the instruction. Also don't let an IRQ sneak
> +     * in before we execute it.
>        */
> -    cpu->cflags_next_tb = curr_cflags(cpu) | CF_MEMI_ONLY | n;
> +    cpu->cflags_next_tb = curr_cflags(cpu) | CF_MEMI_ONLY | CF_NOIRQ | n;
>   
>       if (qemu_loglevel_mask(CPU_LOG_EXEC)) {
>           vaddr pc = cpu->cc->get_pc(cpu);