Re: [PATCH v2 01/12] kexec: Allow architecture code to opt-out at runtime

From: Eric W. Biederman
Date: Mon Nov 01 2021 - 17:12:27 EST


Borislav Petkov <bp@xxxxxxxxx> writes:

> On Mon, Sep 13, 2021 at 05:55:52PM +0200, Joerg Roedel wrote:
>> From: Joerg Roedel <jroedel@xxxxxxx>
>>
>> Allow a runtime opt-out of kexec support for architecture code in case
>> the kernel is running in an environment where kexec is not properly
>> supported yet.
>>
>> This will be used on x86 when the kernel is running as an SEV-ES
>> guest. SEV-ES guests need special handling for kexec to hand over all
>> CPUs to the new kernel. This requires special hypervisor support and
>> handling code in the guest which is not yet implemented.
>>
>> Cc: stable@xxxxxxxxxxxxxxx # v5.10+
>> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
>> ---
>> include/linux/kexec.h | 1 +
>> kernel/kexec.c | 14 ++++++++++++++
>> kernel/kexec_file.c | 9 +++++++++
>> 3 files changed, 24 insertions(+)
>
> I guess I can take this through the tip tree along with the next one.

I seem to remember the consensus when this was reviewed that it was
unnecessary and there is already support for doing something like
this at a more fine grained level so we don't need a new kexec hook.

Eric