Re: [PATCH 03/10] system/bootdevice: Don't unregister reset handler in restore_boot_order()

[Zhao Liu <zhao1.liu@intel.com>]

On Tue, Feb 20, 2024 at 04:06:15PM +0000, Peter Maydell wrote:
> Date: Tue, 20 Feb 2024 16:06:15 +0000
> From: Peter Maydell <peter.maydell@linaro.org>
> Subject: [PATCH 03/10] system/bootdevice: Don't unregister reset handler in
>  restore_boot_order()
> X-Mailer: git-send-email 2.34.1
> 
> Currently the qemu_register_reset() API permits the reset handler functions
> registered with it to remove themselves from within the callback function.
> This is fine with our current implementation, but is a bit odd, because
> generally reset is supposed to be idempotent, and doesn't fit well in a
> three-phase-reset world where a resettable object will get multiple
> callbacks as the system is reset.
> 
> We now have only one user of qemu_register_reset() which makes use of
> the ability to unregister itself within the callback:
> restore_boot_order().  We want to change our implementation of
> qemu_register_reset() to something where it would be awkward to
> maintain the "can self-unregister" feature.  Rather than making that
> reimplementation complicated, change restore_boot_order() so that it
> doesn't unregister itself but instead returns doing nothing for any
> calls after it has done the "restore the boot order" work.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> It would be nicer not to use reset at all, especially since I'm not
> a fan of conflating "system is reset" with "system boots", but I
> didn't have a good idea for how to do that.
> ---
>  system/bootdevice.c | 25 ++++++++++++++-----------
>  1 file changed, 14 insertions(+), 11 deletions(-)

Reviewed-by: Zhao Liu <zhao1.liu@intel.com>