Re: [PATCH] KVM: arm64: vgic: Fix detection of MI on no pending LR

Re: [PATCH] KVM: arm64: vgic: Fix detection of MI on no pending LR

[Marc Zyngier]

[Fixing up the initial recipient list...]

On Mon, 10 Aug 2026 11:29:24 +0100,
Kajetan Puchalski <kajetan.puchalski@arm.com> wrote:
> 
> As per the ARM GICv3 spec, the maintenance interrupt identified by
> ICH_MISR_EL2.NP is asserted when it is enabled and no List register is
> in pending state. This is further described in the document as "no List
> registers with the State field set to 0b01 (pending)". By checking only
> the pending bit of the LR (bit 62), KVM currently asserts the MI when
> there are no LRs in "pending" or "pending and active" states.
> Fix the detection logic to consider only the "pending" state.
> 
> Cc: stable@vger.kernel.org
> Fixes: 96c2f03311de ("KVM: arm64: nv: Plumb handling of GICv3 EL2 accesses")
> Signed-off-by: Kajetan Puchalski <kajetan.puchalski@arm.com>
> ---
>  arch/arm64/kvm/vgic/vgic-v3-nested.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/kvm/vgic/vgic-v3-nested.c b/arch/arm64/kvm/vgic/vgic-v3-nested.c
> index 5c69fa615823..e3e84d7f5ad5 100644
> --- a/arch/arm64/kvm/vgic/vgic-v3-nested.c
> +++ b/arch/arm64/kvm/vgic/vgic-v3-nested.c
> @@ -152,7 +152,7 @@ static void vgic_compute_mi_state(struct kvm_vcpu *vcpu, struct mi_state *mi_sta
>  			eisr |= BIT(i);
>  		if (!(lr & ICH_LR_STATE))
>  			elrsr |= BIT(i);
> -		pend |= (lr & ICH_LR_PENDING_BIT);
> +		pend |= (lr & ICH_LR_STATE) == ICH_LR_PENDING_BIT;
>  	}
>  
>  	mi_state->eisr	= eisr;

Thanks for catching this.

Reviewed-by: Marc Zyngier <maz@kernel.org>

	M.

-- 
Without deviation from the norm, progress is not possible.