Re: [PATCH for-stable-5.10 2/2] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
On Thu, Mar 25, 2021 at 09:33:17AM +, Marc Zyngier wrote: > On 2021-03-25 09:14, Shameer Kolothum wrote: > > From: Marc Zyngier > > > > 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: sta...@vger.kernel.org #5.10 > > Reported-by: Shameerali Kolothum Thodi > > > > Tested-by: Shameer Kolothum > > Signed-off-by: Marc Zyngier > > Message-Id: <20210305185254.3730990-8-...@kernel.org> > > Signed-off-by: Paolo Bonzini > > Signed-off-by: Shameer Kolothum > > 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 ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH for-stable-5.10 2/2] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
On Thu, 25 Mar 2021 09:37:15 +, Shameerali Kolothum Thodi wrote: > > > > > -Original Message- > > From: Marc Zyngier [mailto:m...@kernel.org] > > Sent: 25 March 2021 09:33 > > To: Shameerali Kolothum Thodi > > Cc: kvmarm@lists.cs.columbia.edu; k...@vger.kernel.org; > > linux-arm-ker...@lists.infradead.org; sta...@vger.kernel.org; > > pbonz...@redhat.com; Linuxarm > > 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 > > > > > > 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: sta...@vger.kernel.org #5.10 > > > Reported-by: Shameerali Kolothum Thodi > > > > > > Tested-by: Shameer Kolothum > > > Signed-off-by: Marc Zyngier > > > Message-Id: <20210305185254.3730990-8-...@kernel.org> > > > Signed-off-by: Paolo Bonzini > > > Signed-off-by: Shameer Kolothum > > > > 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. The problem is we'd end-up with 5.10 being subtly broken for a while, and I want to avoid this. Specially given that not having this series only affects broken platforms, while having an incomplete series breaks working systems (which is be counter productive). > Anyway, will wait now. Thanks for that, M. -- Without deviation from the norm, progress is not possible. ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
RE: [PATCH for-stable-5.10 2/2] KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
> -Original Message- > From: Marc Zyngier [mailto:m...@kernel.org] > Sent: 25 March 2021 09:33 > To: Shameerali Kolothum Thodi > Cc: kvmarm@lists.cs.columbia.edu; k...@vger.kernel.org; > linux-arm-ker...@lists.infradead.org; sta...@vger.kernel.org; > pbonz...@redhat.com; Linuxarm > 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 > > > > 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: sta...@vger.kernel.org #5.10 > > Reported-by: Shameerali Kolothum Thodi > > > > Tested-by: Shameer Kolothum > > Signed-off-by: Marc Zyngier > > Message-Id: <20210305185254.3730990-8-...@kernel.org> > > Signed-off-by: Paolo Bonzini > > Signed-off-by: Shameer Kolothum > > 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-...@kernel.org > -- > Jazz is not dead. It just smells funny... ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
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 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: sta...@vger.kernel.org #5.10 Reported-by: Shameerali Kolothum Thodi Tested-by: Shameer Kolothum Signed-off-by: Marc Zyngier Message-Id: <20210305185254.3730990-8-...@kernel.org> Signed-off-by: Paolo Bonzini Signed-off-by: Shameer Kolothum 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. Thanks, M. [1] https://lore.kernel.org/r/20210323162301.2049595-1-...@kernel.org -- Jazz is not dead. It just smells funny... ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
