From: Shenming Lu <lushenming@huawei.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Eric Auger <eric.auger@redhat.com>, Will Deacon <will@kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<kvmarm@lists.cs.columbia.edu>, <kvm@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
Alex Williamson <alex.williamson@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
<wanghaibin.wang@huawei.com>, <yuzenghui@huawei.com>
Subject: Re: [PATCH v3 3/4] KVM: arm64: GICv4.1: Restore VLPI's pending state to physical side
Date: Thu, 11 Mar 2021 20:32:07 +0800 [thread overview]
Message-ID: <0820f429-4c29-acd6-d9e0-af9f6deb68e4@huawei.com> (raw)
In-Reply-To: <87tupif3x3.wl-maz@kernel.org>
On 2021/3/11 17:14, Marc Zyngier wrote:
> On Wed, 27 Jan 2021 12:13:36 +0000,
> Shenming Lu <lushenming@huawei.com> wrote:
>>
>> From: Zenghui Yu <yuzenghui@huawei.com>
>>
>> When setting the forwarding path of a VLPI (switch to the HW mode),
>> we could also transfer the pending state from irq->pending_latch to
>> VPT (especially in migration, the pending states of VLPIs are restored
>> into kvm’s vgic first). And we currently send "INT+VSYNC" to trigger
>> a VLPI to pending.
>>
>> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
>> Signed-off-by: Shenming Lu <lushenming@huawei.com>
>> ---
>> arch/arm64/kvm/vgic/vgic-v4.c | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
>> index ac029ba3d337..a3542af6f04a 100644
>> --- a/arch/arm64/kvm/vgic/vgic-v4.c
>> +++ b/arch/arm64/kvm/vgic/vgic-v4.c
>> @@ -449,6 +449,20 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
>> irq->host_irq = virq;
>> atomic_inc(&map.vpe->vlpi_count);
>>
>> + /* Transfer pending state */
>> + if (irq->pending_latch) {
>> + ret = irq_set_irqchip_state(irq->host_irq,
>> + IRQCHIP_STATE_PENDING,
>> + irq->pending_latch);
>> + WARN_RATELIMIT(ret, "IRQ %d", irq->host_irq);
>> +
>> + /*
>> + * Let it be pruned from ap_list later and don't bother
>> + * the List Register.
>> + */
>> + irq->pending_latch = false;
>
> NAK. If the interrupt is on the AP list, it must be pruned from it
> *immediately*. The only case where it can be !pending and still on the
> AP list is in interval between sync and prune. If we start messing
> with this, we can't reason about the state of this list anymore.
>
> Consider calling vgic_queue_irq_unlock() here.
Thanks for giving a hint, but it seems that vgic_queue_irq_unlock() only
queues an IRQ after checking, did you mean vgic_prune_ap_list() instead?
Thanks a lot for the comments! :-)
Shenming
>
> Thanks,
>
> M.
>
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next prev parent reply other threads:[~2021-03-11 12:34 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 12:13 [PATCH v3 0/4] KVM: arm64: Add VLPI migration support on GICv4.1 Shenming Lu
2021-01-27 12:13 ` [PATCH v3 1/4] KVM: arm64: GICv4.1: Add function to get VLPI state Shenming Lu
2021-03-11 8:57 ` Marc Zyngier
2021-03-11 12:26 ` Shenming Lu
2021-03-12 8:52 ` Marc Zyngier
2021-01-27 12:13 ` [PATCH v3 2/4] KVM: arm64: GICv4.1: Try to save hw pending state in save_pending_tables Shenming Lu
2021-03-11 9:09 ` Marc Zyngier
2021-03-11 12:31 ` Shenming Lu
2021-03-12 9:02 ` Marc Zyngier
2021-03-12 10:47 ` Shenming Lu
2021-01-27 12:13 ` [PATCH v3 3/4] KVM: arm64: GICv4.1: Restore VLPI's pending state to physical side Shenming Lu
2021-03-11 9:14 ` Marc Zyngier
2021-03-11 12:32 ` Shenming Lu [this message]
2021-03-12 9:05 ` Marc Zyngier
2021-03-12 10:48 ` Shenming Lu
2021-03-12 11:10 ` Marc Zyngier
2021-03-12 11:34 ` Shenming Lu
2021-03-12 12:02 ` Marc Zyngier
2021-03-12 12:31 ` Shenming Lu
2021-01-27 12:13 ` [PATCH v3 4/4] KVM: arm64: GICv4.1: Give a chance to save VLPI's pending state Shenming Lu
2021-02-26 8:58 ` [PATCH v3 0/4] KVM: arm64: Add VLPI migration support on GICv4.1 Shenming Lu
2021-03-11 7:03 ` Shenming Lu
2021-03-11 9:17 ` Marc Zyngier
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