Re: [PATCH v2 07/14] accel/stubs: Expand stubs for TCG

[Thomas Huth <thuth@redhat.com>]

On 03/02/2025 04.18, Richard Henderson wrote:
> Add tcg_allowed, qmp_x_query_jit, qmp_x_query_opcount.
> These are referenced when CONFIG_TCG is enabled globally,
> but not for a specific target.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   accel/stubs/tcg-stub.c | 24 ++++++++++++++++++++++++
>   1 file changed, 24 insertions(+)
> 
> diff --git a/accel/stubs/tcg-stub.c b/accel/stubs/tcg-stub.c
> index 7f4208fddf..9c2e2dc6e1 100644
> --- a/accel/stubs/tcg-stub.c
> +++ b/accel/stubs/tcg-stub.c
> @@ -13,6 +13,18 @@
>   #include "qemu/osdep.h"
>   #include "exec/tb-flush.h"
>   #include "exec/exec-all.h"
> +#include "qapi/error.h"
> +
> +/*
> + * This file *ought* to be built once and linked only when required.
> + * However, it is built per-target, which means qemu/osdep.h has already
> + * undef'ed CONFIG_TCG, which hides the auto-generated declaration.

So why don't we only build this file once?

  Thomas


> + */
> +#define CONFIG_TCG
> +#include "qapi/qapi-commands-machine.h"
> +
> +
> +const bool tcg_allowed = false;
>   
>   void tb_flush(CPUState *cpu)
>   {
> @@ -27,3 +39,15 @@ G_NORETURN void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
>   {
>       g_assert_not_reached();
>   }
> +
> +HumanReadableText *qmp_x_query_jit(Error **errp)
> +{
> +    error_setg(errp, "JIT information is only available with accel=tcg");
> +    return NULL;
> +}
> +
> +HumanReadableText *qmp_x_query_opcount(Error **errp)
> +{
> +    error_setg(errp, "Opcode count information is only available with accel=tcg");
> +    return NULL;
> +}