Re: [PATCH v4 02/17] x86/acrn: Introduce acrn_{setup, remove}_intr_handler()

[Borislav Petkov]

On Tue, Sep 22, 2020 at 07:42:56PM +0800, shuo.a.liu@xxxxxxxxx wrote:
> +void acrn_setup_intr_handler(void (*handler)(void))
> +{
> +	acrn_intr_handler = handler;
> +}
> +EXPORT_SYMBOL_GPL(acrn_setup_intr_handler);
> +
> +void acrn_remove_intr_handler(void)
> +{
> +	acrn_intr_handler = NULL;
> +}
> +EXPORT_SYMBOL_GPL(acrn_remove_intr_handler);

I don't like this one bit.

Also, what stops the module from doing acrn_remove_intr_handler()
while it gets a HYPERVISOR_CALLBACK_VECTOR interrupt and the handler
disappearing from under it?

IOW, this should be an atomic notifier instead.

Thx.

-- 
Regards/Gruss,
    Boris.

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