From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752654AbdKHOOP (ORCPT ); Wed, 8 Nov 2017 09:14:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51704 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751754AbdKHOOM (ORCPT ); Wed, 8 Nov 2017 09:14:12 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E06AC5F34 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=eric.auger@redhat.com Subject: Re: [PATCH v5 11/26] KVM: arm/arm64: GICv4: Handle INT command applied to a VLPI To: Marc Zyngier , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20171027142855.21584-1-marc.zyngier@arm.com> <20171027142855.21584-12-marc.zyngier@arm.com> <6e12eac9-7b75-2c2c-0c79-d17a3c0d65eb@redhat.com> <26647099-f16c-f4ef-6902-ebbfb7a40a3a@arm.com> Cc: Mark Rutland , Christoffer Dall , Andre Przywara , Shameerali Kolothum Thodi , Christoffer Dall , Shanker Donthineni From: Auger Eric Message-ID: <5c6f1428-2cf8-0a28-7554-d45dd53f2179@redhat.com> Date: Wed, 8 Nov 2017 15:14:07 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <26647099-f16c-f4ef-6902-ebbfb7a40a3a@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 08 Nov 2017 14:14:12 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Marc, On 08/11/2017 12:40, Marc Zyngier wrote: > On 07/11/17 20:15, Auger Eric wrote: >> Hi Marc, >> >> On 27/10/2017 16:28, Marc Zyngier wrote: >>> If the guest issues an INT command targetting a VLPI, let's >>> call into the irq_set_irqchip_state() helper to make it pending >>> on the physical side. >>> >>> This works just as well if userspace decides to inject an interrupt >>> using the normal userspace API... >> There is also another path: >> KVM_SIGNAL_MSI ioctl / kvm_send_userspace_msi / kvm_set_msi / >> vgic_its_inject_msi / vgic_its_trigger_msi > > Isn't this path covered by this very patch? I should have read the last sentence of the commit msg to see you haven't ignored it ;-) > >> I wonder whether we shouldn't prevent the userspace from messing up with >> the host irq pending state? > > What do we gain from that limitation? Here, we're just making sure > things will work correctly, and we're not preventing userspace from > doing something silly (the guest will only see spurious interrupts anyway). OK. Just wanted to make sure this was not an issue. Thanks Eric > > Thanks, > > M. > >> Thanks >> >> Eric >>> >>> Acked-by: Christoffer Dall >>> Signed-off-by: Marc Zyngier >>> --- >>> virt/kvm/arm/vgic/vgic-its.c | 4 ++++ >>> 1 file changed, 4 insertions(+) >>> >>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c >>> index 89768d2b6a91..b2a678d131d0 100644 >>> --- a/virt/kvm/arm/vgic/vgic-its.c >>> +++ b/virt/kvm/arm/vgic/vgic-its.c >>> @@ -578,6 +578,10 @@ static int vgic_its_trigger_msi(struct kvm *kvm, struct vgic_its *its, >>> if (err) >>> return err; >>> >>> + if (irq->hw) >>> + return irq_set_irqchip_state(irq->host_irq, >>> + IRQCHIP_STATE_PENDING, true); >>> + >>> spin_lock(&irq->irq_lock); >>> irq->pending_latch = true; >>> vgic_queue_irq_unlock(kvm, irq); >>> > >