Re: [PATCH v3 49/59] KVM: arm/arm64: GICv4: Propagate VLPI properties at map time

Christoffer Dall
2017-08-28T18:18:41Z

On Mon, Jul 31, 2017 at 06:26:27PM +0100, Marc Zyngier wrote:
> When the VLPI gets mapped, it must inherit the configuration of
> LPI configured at the vITS level. FOr that purpose, let's make

*the LPI
*For that

> update_lpi_config globally available and call it just after
> having performed the VLPI map operation.
>

I assume this means that the GIC compares the priorities of virtual
interrupts in the LRs with the priorities of the pending VLPIs and
figures out what to signal first? I couldn't find anywhere in the spec
where this is explicitly stated.

> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> virt/kvm/arm/vgic/vgic-its.c | 6 ++----
> virt/kvm/arm/vgic/vgic-v4.c | 2 ++
> virt/kvm/arm/vgic/vgic.h | 2 ++
> 3 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index b395df1bf47c..d790d0c74b8b 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -37,8 +37,6 @@
> static int vgic_its_save_tables_v0(struct vgic_its *its);
> static int vgic_its_restore_tables_v0(struct vgic_its *its);
> static int vgic_its_commit_v0(struct vgic_its *its);
> -static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> - struct kvm_vcpu *filter_vcpu, bool needs_inv);
>
> /*
> * Creates a new (reference to a) struct vgic_irq for a given LPI.
> @@ -273,8 +271,8 @@ static struct its_collection *find_collection(struct vgic_its *its, int coll_id)
> * If filter_vcpu is not NULL, applies only if the IRQ is targeting this
> * VCPU. Unconditionally applies if filter_vcpu is NULL.
> */
> -static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> - struct kvm_vcpu *filter_vcpu, bool needs_inv)
> +int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> + struct kvm_vcpu *filter_vcpu, bool needs_inv)
> {
> u64 propbase = GICR_PROPBASER_ADDRESS(kvm->arch.vgic.propbaser);
> u8 prop;
> diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
> index 338c86c5159f..534d3051a078 100644
> --- a/virt/kvm/arm/vgic/vgic-v4.c
> +++ b/virt/kvm/arm/vgic/vgic-v4.c
> @@ -137,6 +137,8 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
> irq->hw = true;
> irq->host_irq = virq;
>
> + /* Force the property update and invalidate */
> + update_lpi_config(kvm, irq, NULL, true);
> out:
> mutex_unlock(&its->its_lock);
> return 0;
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 1356f485d7cf..1210bf4681dc 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -228,6 +228,8 @@ void unlock_all_vcpus(struct kvm *kvm);
> int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
> u32 devid, u32 eventid, struct vgic_irq **irq);
> struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
> +int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq,
> + struct kvm_vcpu *filter_vcpu, bool needs_inv);
>
> bool vgic_is_v4_capable(struct kvm *kvm);
> int vgic_v4_init(struct kvm *kvm);
> --
> 2.11.0
>

Acked-by: Christoffer Dall <cdall@linaro.org>