[PATCHv10 09/18] x86/mm: Adding callbacks to prepare encrypted memory for kexec

[Borislav Petkov]

On Tue, Apr 09, 2024 at 02:30:01PM +0300, Kirill A. Shutemov wrote:
> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
> index e74d0c4286c1..7a1560d7e62d 100644
> --- a/arch/x86/kernel/crash.c
> +++ b/arch/x86/kernel/crash.c
> @@ -128,6 +128,12 @@ void native_machine_crash_shutdown(struct pt_regs *regs)
>  #ifdef CONFIG_HPET_TIMER
>  	hpet_disable();
>  #endif
> +
> +	if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
> +		x86_platform.guest.enc_kexec_stop_conversion(true);
> +		x86_platform.guest.enc_kexec_unshare_mem();
> +	}

This is not how this is done - the point of those function pointers is
to avoid random checks in the code but simply unconditionally call them.

The platform which needs something special to happen, assigns to them
its own function pointers and the rest assigns dummy stubs.

-- 
Regards/Gruss,
    Boris.

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