Re: WTF: patch "[PATCH] arm/arm64: KVM: Add PSCI version selection API" was seriously submitted to be applied to the 4.16-stable tree?

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Apr 30, 2018 at 04:37:48PM +0200, Christoffer Dall wrote:
> On Sun, Apr 29, 2018 at 02:34:45PM +0200, gregkh@linuxfoundation.org wrote:
> > The patch below was submitted to be applied to the 4.16-stable tree.
> > 
> > I fail to see how this patch meets the stable kernel rules as found at
> > Documentation/process/stable-kernel-rules.rst.
> > 
> > I could be totally wrong, and if so, please respond to 
> > <stable@vger.kernel.org> and let me know why this patch should be
> > applied.  Otherwise, it is now dropped from my patch queues, never to be
> > seen again.
> 
> This patch ensures that current userspace drivers of KVM VMs will fail
> migration to targets that do not support spectre/meltdown mitigations.
> Without this patch, VMs can be migrated to hosts that do not have
> mitigation support without any warning to the system admin.  We
> considered this a real security issue as per the stable kernel rules.
> 
> If you disagree, feel free to drop this patch without further
> discussion.
> 
> Thanks,
> -Christoffer
> 
> > 
> > ------------------ original commit in Linus's tree ------------------
> > 
> > From 85bd0ba1ff9875798fad94218b627ea9f768f3c3 Mon Sep 17 00:00:00 2001
> > From: Marc Zyngier <marc.zyngier@arm.com>
> > Date: Sun, 21 Jan 2018 16:42:56 +0000
> > Subject: [PATCH] arm/arm64: KVM: Add PSCI version selection API
> > 
> > Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1
> > or 1.0 to a guest, defaulting to the latest version of the PSCI
> > implementation that is compatible with the requested version. This is
> > no different from doing a firmware upgrade on KVM.
> > 
> > But in order to give a chance to hypothetical badly implemented guests
> > that would have a fit by discovering something other than PSCI 0.2,
> > let's provide a new API that allows userspace to pick one particular
> > version of the API.
> > 
> > This is implemented as a new class of "firmware" registers, where
> > we expose the PSCI version. This allows the PSCI version to be
> > save/restored as part of a guest migration, and also set to
> > any supported version if the guest requires it.
> > 
> > Cc: stable@vger.kernel.org #4.16
> > Reviewed-by: Christoffer Dall <cdall@kernel.org>
> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Also, it looks like this applies cleanly to 4.14.y, do you want it there
as well?

thanks,

greg k-h