On Fri, Sep 28, 2018 at 11:52:21AM +0800, lijiang wrote:
> There are two functions that are usually called in pairs, they are:
> arch_kexec_post_alloc_pages() and arch_kexec_pre_free_pages().
>
> One marks the pages as decrypted, another one marks the pages as encrypted.
>
> But for the crash control pages, no need to call arch_kexec_pre_free_pages(),
> there are three reasons:
> 1. Crash pages are reserved in memblock, these pages are only used by kdump,
> no other people uses these pages;
>
> 2. Whenever crash pages are allocated, these pages are always marked as
> decrypted(when SME is active);
>
> 3. If we plan to call the arch_kexe_pre_free_pages(), we have to store these
> pages to somewhere, which will have more code changes.
I don't think any of that answers the question *why* control pages do
not need to be marked encrypted again. And I think the reason is simple:
because you don't really need to, because once the crash kernel is done,
you reboot the box.
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
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