Re: [PATCH v7 14/18] cpu: Call plugin hooks only when ready

[Akihiko Odaki]

On 2023/09/12 17:46, Philippe Mathieu-Daudé wrote:
> Hi Akihiko,
>
> On 12/9/23 09:12, Akihiko Odaki wrote:
> > The initialization and exit hooks will not affect the state of vCPU,
>
> What about:
>
>   qemu_plugin_vcpu_init_hook()
>     -> plugin_cpu_update__locked()
>        -> plugin_cpu_update__async()
>           -> bitmap_copy(cpu->plugin_mask, ...)
>              tcg_flush_jmp_cache(cpu)
>              -> qatomic_set(&cpu->tb_jmp_cache->array[i].tb, ...)
>
> ?

Hi,

bitmap_copy(cpu->plugin_mask, ...) is contained in the plugin 
infrastructure and shouldn't matter.

The TCG is not started filling caches so tcg_flush_jmp_cache() is 
effectively nop though that is not clearly stated.

By the way, I found plugin_cpu_update__locked() will not synchronously 
call plugin_cpu_update__async() after this change because cpu->created 
will be always true for the system emulation. For user space emulation, 
it has already been broken and it *always* synchronously calls the 
function since cpu->created is not set.

I wrote a change to replace cpu->created with DEVICE(cpu)->realized and 
added to the base patch series ("[PATCH v3 03/12] plugins: Check if vCPU 
is realized" in "[PATCH v3 00/12] gdbstub and TCG plugin improvements").

Regards,
Akihiko Odaki