From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoffer Dall Subject: Re: [PATCH v5 16/26] KVM: arm/arm64: GICv4: Propagate property updates to VLPIs Date: Fri, 10 Nov 2017 09:37:55 +0100 Message-ID: <20171110083755.GI14144@cbox> References: <20171027142855.21584-1-marc.zyngier@arm.com> <20171027142855.21584-17-marc.zyngier@arm.com> <6763d90f-93bf-ddbb-d456-5979b8870aa2@redhat.com> <49bff080-0908-cc7a-7036-543f963180a5@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Auger Eric , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Rutland , Andre Przywara , Shameerali Kolothum Thodi , Christoffer Dall , Shanker Donthineni To: Marc Zyngier Return-path: Received: from mail-wm0-f68.google.com ([74.125.82.68]:55507 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965AbdKJIhw (ORCPT ); Fri, 10 Nov 2017 03:37:52 -0500 Received: by mail-wm0-f68.google.com with SMTP id b189so1038768wmd.4 for ; Fri, 10 Nov 2017 00:37:51 -0800 (PST) Content-Disposition: inline In-Reply-To: <49bff080-0908-cc7a-7036-543f963180a5@arm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Nov 08, 2017 at 03:08:36PM +0000, Marc Zyngier wrote: > On 07/11/17 21:28, Auger Eric wrote: > > Hi Marc, > > > > On 27/10/2017 16:28, Marc Zyngier wrote: > >> Upon updating a property, we propagate it all the way to the physical > >> ITS, and ask for an INV command to be executed there. > >> > >> Acked-by: Christoffer Dall > >> Signed-off-by: Marc Zyngier > >> --- > >> virt/kvm/arm/vgic/vgic-its.c | 3 +++ > >> 1 file changed, 3 insertions(+) > >> > >> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c > >> index 0b7e648e7a0c..2e77c7c83942 100644 > >> --- a/virt/kvm/arm/vgic/vgic-its.c > >> +++ b/virt/kvm/arm/vgic/vgic-its.c > >> @@ -296,6 +296,9 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, > >> spin_unlock(&irq->irq_lock); > >> } > >> > >> + if (irq->hw) > >> + return its_prop_update_vlpi(irq->host_irq, prop, true); > >> + > >> return 0; > >> } > > I am confused by the vgic_queue_irq_unlock() on the "hw" path. Why is it > > needed in hw mode? > > It's not. I guess we could bypass this altogether and take a short cut > after having updated the priority and enabled fields. > I can apply this on top of the series as well if you're happy with it: commit b54fba93b1330803a59ca75f3a5102e22cadc871 (HEAD -> next-gicv4) Author: Christoffer Dall Date: Fri Nov 10 09:34:54 2017 +0100 KVM: arm/arm64: Don't queue VLPIs on INV/INVALL Since VLPIs are injected directly by the hardware there's no need to mark these as pending in software and queue them on the AP list. Signed-off-by: Christoffer Dall diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index c93ecd4a903b..a3754ec719c4 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -292,11 +292,14 @@ static int update_lpi_config(struct kvm *kvm, struct vgic_irq *irq, irq->priority = LPI_PROP_PRIORITY(prop); irq->enabled = LPI_PROP_ENABLE_BIT(prop); - vgic_queue_irq_unlock(kvm, irq, flags); - } else { - spin_unlock_irqrestore(&irq->irq_lock, flags); + if (!irq->hw) { + vgic_queue_irq_unlock(kvm, irq, flags); + return 0; + } } + spin_unlock_irqrestore(&irq->irq_lock, flags); + if (irq->hw) return its_prop_update_vlpi(irq->host_irq, prop, needs_inv); Thanks, -Christoffer