> -----Original Message----- > From: Marc Zyngier [mailto:maz@xxxxxxxxxx] > Sent: 25 March 2021 09:33 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@xxxxxxxxxx> > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; stable@xxxxxxxxxxxxxxx; > pbonzini@xxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx> > Subject: Re: [PATCH for-stable-5.10 2/2] KVM: arm64: Workaround firmware > wrongly advertising GICv2-on-v3 compatibility > > On 2021-03-25 09:14, Shameer Kolothum wrote: > > From: Marc Zyngier <maz@xxxxxxxxxx> > > > > 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@xxxxxxxxxxxxxxx #5.10 > > Reported-by: Shameerali Kolothum Thodi > > <shameerali.kolothum.thodi@xxxxxxxxxx> > > Tested-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> > > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> > > Message-Id: <20210305185254.3730990-8-maz@xxxxxxxxxx> > > Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> > > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx> > > 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. Ok. Yes, I noted that. But was thinking if this goes through first and then we can have a stable tag for that one, we can manage it. Anyway, will wait now. Thanks, Shameer > Thanks, > > M. > > [1] https://lore.kernel.org/r/20210323162301.2049595-1-maz@xxxxxxxxxx > -- > Jazz is not dead. It just smells funny...
