Re: [PATCH stable v5.4 1/3] KVM: arm64: Add kvm_extable for vaxoricism code

[Marc Zyngier <maz@kernel.org>]

On 2020-09-01 12:17, André Przywara wrote:
> On 01/09/2020 12:12, Marc Zyngier wrote:
>> Hi Andre,
>> 
>> On 2020-09-01 10:49, Andre Przywara wrote:
>>> From: James Morse <james.morse@arm.com>
>>> 
>>> commit e9ee186bb735bfc17fa81dbc9aebf268aee5b41e upstream.
>>> 
>>> KVM has a one instruction window where it will allow an SError 
>>> exception
>>> to be consumed by the hypervisor without treating it as a hypervisor 
>>> bug.
>>> This is used to consume asynchronous external abort that were caused 
>>> by
>>> the guest.
>>> 
>>> As we are about to add another location that survives unexpected
>>> exceptions,
>>> generalise this code to make it behave like the host's extable.
>>> 
>>> KVM's version has to be mapped to EL2 to be accessible on nVHE 
>>> systems.
>>> 
>>> The SError vaxorcism code is a one instruction window, so has two 
>>> entries
>>> in the extable. Because the KVM code is copied for VHE and nVHE, we
>>> end up
>>> with four entries, half of which correspond with code that isn't 
>>> mapped.
>>> 
>>> Cc: <stable@vger.kernel.org> # 5.4.x
>>> Cc: Marc Zyngier <maz@kernel.org>
>>> Signed-off-by: James Morse <james.morse@arm.com>
>>> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
>> 
>> Can you make sure these patches do carry the sign-off chain as we have
>> in mainline? In particular, this is missing:
>> 
>>     Reviewed-by: Marc Zyngier <maz@kernel.org>
>>     Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
>> 
>> You can add your own SoB after this.
> 
> Sure, I wasn't sure your review would apply to this version as well. I
> took the backports from James' kernel.org repo, where they were lacking
> any of those tags.
> So shall I copy all the tags from mainline to all backport versions? Or
> only to those where the changes were trivial? The backports to before
> 5.3 seem to be more involved.

My understanding is that the commit log should stay as close to the
original as possible, with potential additions to indicate deviations
from the upstream patch.

I'm happy to *add* another RB once I have reviewed the patch, just
like I add another SoB when I backport a patch on which I signed-off
the first place.

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...