[PATCHv7 11/14] x86: Disable kexec if system has unaccepted memory

[Dave Hansen]

... adding kexec folks

On 6/14/22 05:02, Kirill A. Shutemov wrote:
> On kexec, the target kernel has to know what memory has been accepted.
> Information in EFI map is out of date and cannot be used.
> 
> boot_params.unaccepted_memory can be used to pass the bitmap between two
> kernels on kexec, but the use-case is not yet implemented.
> 
> Disable kexec on machines with unaccepted memory for now.
...
> +static int __init unaccepted_init(void)
> +{
> +	if (!boot_params.unaccepted_memory)
> +		return 0;
> +
> +#ifdef CONFIG_KEXEC_CORE
> +	/*
> +	 * TODO: Information on memory acceptance status has to be communicated
> +	 * between kernel.
> +	 */
> +	pr_warn("Disable kexec: not yet supported on systems with unaccepted memory\n");
> +	kexec_load_disabled = 1;
> +#endif

This looks to be the *only* in-kernel user tweaking kexec_load_disabled.
 It doesn't feel great to just be disabling kexec like this.  Why not
just fix it properly?

What do the kexec folks think?