On Thu, Mar 25, 2021 at 09:33:17AM +0000, Marc Zyngier wrote:

On 2021-03-25 09:14, Shameer Kolothum wrote:

quoted

From: Marc Zyngier <maz@kernel.org>

commit 9739f6ef053f104a997165701c6e15582c4307ee upstream.

It looks like we have broken firmware out there that wrongly advertises
a GICv2 compatibility interface, despite the CPUs not being able to deal
with it.

To work around this, check that the CPU initialising KVM is actually
able
to switch to MMIO instead of system registers, and use that as a
precondition to enable GICv2 compatibility in KVM.

Note that the detection happens on a single CPU. If the firmware is
lying *and* that the CPUs are asymetric, all hope is lost anyway.

Cc: stable@vger.kernel.org #5.10
Reported-by: Shameerali Kolothum Thodi
[off-list ref]
Tested-by: Shameer Kolothum <redacted>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: [off-list ref]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Shameer Kolothum <redacted>

Please hold on on that.

This patch causes a regression, and needs a fix that is currently queued
for 5.12 [1]. Once this hits upstream, please add the fix to the series
and post it as a whole.

Both patches now dropped from my queue, thanks.

greg k-h