Re: Patch "KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt" has been added to the 4.9-stable tree

From: Greg KH <gregkh@linuxfoundation.org>
To: Marc Zyngier <marc.zyngier@arm.com>
Cc: cdall@linaro.org, stable@vger.kernel.org, stable-commits@vger.kernel.org
Subject: Re: Patch "KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt" has been added to the 4.9-stable tree
Date: Mon, 12 Jun 2017 10:19:58 +0200	[thread overview]
Message-ID: <20170612081958.GB28437@kroah.com> (raw)
In-Reply-To: <7d0151d3-71f4-5b8b-d782-054d848785ed@arm.com>

On Wed, May 24, 2017 at 08:54:58AM +0100, Marc Zyngier wrote:
> On 24/05/17 08:08, Greg KH wrote:
> > On Tue, May 23, 2017 at 04:48:28PM +0200, gregkh@linuxfoundation.org wrote:
> >>
> >> This is a note to let you know that I've just added the patch titled
> >>
> >>     KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt
> >>
> >> to the 4.9-stable tree which can be found at:
> >>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> >>
> >> The filename of the patch is:
> >>      kvm-arm-arm64-vgic-v3-do-not-use-active-pending-state-for-a-hw-interrupt.patch
> >> and it can be found in the queue-4.9 subdirectory.
> >>
> >> If you, or anyone else, feels it should not be added to the stable tree,
> >> please let <stable@vger.kernel.org> know about it.
> >>
> >>
> >> >From 3d6e77ad1489650afa20da92bb589c8778baa8da Mon Sep 17 00:00:00 2001
> >> From: Marc Zyngier <marc.zyngier@arm.com>
> >> Date: Tue, 2 May 2017 14:30:40 +0100
> >> Subject: KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt
> >>
> >> From: Marc Zyngier <marc.zyngier@arm.com>
> >>
> >> commit 3d6e77ad1489650afa20da92bb589c8778baa8da upstream.
> >>
> >> When an interrupt is injected with the HW bit set (indicating that
> >> deactivation should be propagated to the physical distributor),
> >> special care must be taken so that we never mark the corresponding
> >> LR with the Active+Pending state (as the pending state is kept in
> >> the physycal distributor).
> >>
> >> Fixes: 59529f69f504 ("KVM: arm/arm64: vgic-new: Add GICv3 world switch backend")
> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> >> Reviewed-by: Christoffer Dall <cdall@linaro.org>
> >> Signed-off-by: Christoffer Dall <cdall@linaro.org>
> >> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> >>
> >> ---
> >>  virt/kvm/arm/vgic/vgic-v3.c |    7 +++++++
> >>  1 file changed, 7 insertions(+)
> >>
> >> --- a/virt/kvm/arm/vgic/vgic-v3.c
> >> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> >> @@ -151,6 +151,13 @@ void vgic_v3_populate_lr(struct kvm_vcpu
> >>  	if (irq->hw) {
> >>  		val |= ICH_LR_HW;
> >>  		val |= ((u64)irq->hwintid) << ICH_LR_PHYS_ID_SHIFT;
> >> +		/*
> >> +		 * Never set pending+active on a HW interrupt, as the
> >> +		 * pending state is kept at the physical distributor
> >> +		 * level.
> >> +		 */
> >> +		if (irq->active && irq_is_pending(irq))
> > 
> > irq_is_pending() isn't in 4.9, so can someone please send me a proper
> > backported patch?  I've dropped this from the tree now as it causes a
> > build breakage.
> 
> Here's the amended patch:

Thanks, now applied.

greg k-h