[PATCH v2 6/7] KVM: arm64: vgic-its: Fix MOVALL handling of source redistributor

[Fuad Tabba]

On Tue, 29 Sept 2026 at 10:36, Marc Zyngier <maz at kernel.org> wrote:
>
> The MOVALL command moves the pending state of all LPIs targeting a given
> redistributor to another one. However, we seem to have lost the
> filtering on the source RD, which means we move all LPIs to the target.
>
> Not quite what the spec mandates.
>
> Hack update_affinity() to take an optional source vcpu that is used as a
> filter when non-NULL, restoring the filtering that was performed by
> vgic_copy_lpi_list() back in the days.
>
> Fixes: 11f4f8f3e6e06 ("KVM: arm64: vgic-its: Walk LPI xarray in vgic_its_cmd_handle_movall()")
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> Cc: stable at vger.kernel.org

Reviewed-by: Fuad Tabba <fuad.tabba at linux.dev>
Tested-by: Fuad Tabba < fuad.tabba at linux.dev>

Cheers,
/fuad


> ---
>  arch/arm64/kvm/vgic/vgic-its.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
> index 9e782a4fea7e5..cc02d9b62bd95 100644
> --- a/arch/arm64/kvm/vgic/vgic-its.c
> +++ b/arch/arm64/kvm/vgic/vgic-its.c
> @@ -319,12 +319,16 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
>         return ret;
>  }
>
> -static int update_affinity(struct vgic_irq *irq, struct kvm_vcpu *vcpu)
> +static int update_affinity(struct vgic_irq *irq,
> +                          struct kvm_vcpu *from_vcpu, struct kvm_vcpu *vcpu)
>  {
>         struct its_vlpi_map map;
>         int ret;
>
>         guard(raw_spinlock_irqsave)(&irq->irq_lock);
> +       if (from_vcpu && irq->target_vcpu != from_vcpu)
> +               return 0;
> +
>         irq->target_vcpu = vcpu;
>
>         if (!irq->hw)
> @@ -362,7 +366,7 @@ static void update_affinity_ite(struct kvm *kvm, struct its_ite *ite)
>                 return;
>
>         vcpu = collection_to_vcpu(kvm, ite->collection);
> -       update_affinity(ite->irq, vcpu);
> +       update_affinity(ite->irq, NULL, vcpu);
>  }
>
>  /*
> @@ -856,7 +860,7 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>
>         vgic_its_invalidate_cache(its);
>
> -       return update_affinity(ite->irq, vcpu);
> +       return update_affinity(ite->irq, NULL, vcpu);
>  }
>
>  static bool __is_visible_gfn_locked(struct vgic_its *its, gpa_t gpa)
> @@ -1383,7 +1387,7 @@ static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
>                 if (!irq)
>                         continue;
>
> -               update_affinity(irq, vcpu2);
> +               update_affinity(irq, vcpu1, vcpu2);
>
>                 vgic_put_irq(kvm, irq);
>         }
> --
> 2.47.3
>