From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754743AbeDZJZO (ORCPT ); Thu, 26 Apr 2018 05:25:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59566 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754116AbeDZJZL (ORCPT ); Thu, 26 Apr 2018 05:25:11 -0400 Subject: Re: [PATCH v3 08/12] KVM: arm/arm64: Check vcpu redist base before registering an iodev To: Christoffer Dall References: <1523607658-9166-1-git-send-email-eric.auger@redhat.com> <1523607658-9166-9-git-send-email-eric.auger@redhat.com> <20180424210759.GI4533@C02W217FHV2R.local> Cc: eric.auger.pro@gmail.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, marc.zyngier@arm.com, cdall@kernel.org, peter.maydell@linaro.org, andre.przywara@arm.com, drjones@redhat.com, wei@redhat.com From: Auger Eric Message-ID: <73b8e64b-3c14-b937-487a-78f3cc73fde5@redhat.com> Date: Thu, 26 Apr 2018 11:25:06 +0200 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: <20180424210759.GI4533@C02W217FHV2R.local> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoffer, On 04/24/2018 11:07 PM, Christoffer Dall wrote: > On Fri, Apr 13, 2018 at 10:20:54AM +0200, Eric Auger wrote: >> As we are going to register several redist regions, >> vgic_register_all_redist_iodevs() may be called several times. We need >> to register a redist_iodev for a given vcpu only once. > > Wouldn't it be more natural to change that caller to only register the > iodevs for that region? vgic_register_redist_iodev() is the place where we decide where we map a given vcpu redist into a given redist region. Calling vgic_register_redist_iodev for only the vcpus mapping to the redist region would force to inverse the logic. I think it would bring more upheavals in the code than bringing benefit? This new check somehow corresponds to what we had before: " if (IS_VGIC_ADDR_UNDEF(vgic->vgic_redist_base)) return 0; " Thanks Eric > > Thanks, > -Christoffer > >> So let's >> check if the base address has already been set. Initialize this latter >> in kvm_vgic_vcpu_early_init(). >> >> Signed-off-by: Eric Auger >> --- >> virt/kvm/arm/vgic/vgic-init.c | 3 +++ >> virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 +++ >> 2 files changed, 6 insertions(+) >> >> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c >> index 6456371..7e040e7 100644 >> --- a/virt/kvm/arm/vgic/vgic-init.c >> +++ b/virt/kvm/arm/vgic/vgic-init.c >> @@ -82,6 +82,9 @@ void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu) >> INIT_LIST_HEAD(&vgic_cpu->ap_list_head); >> spin_lock_init(&vgic_cpu->ap_list_lock); >> >> + vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; >> + vgic_cpu->sgi_iodev.base_addr = VGIC_ADDR_UNDEF; >> + >> /* >> * Enable and configure all SGIs to be edge-triggered and >> * configure all PPIs as level-triggered. >> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> index 5273fb8..df23e66 100644 >> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c >> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c >> @@ -592,6 +592,9 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu) >> gpa_t rd_base, sgi_base; >> int ret; >> >> + if (!IS_VGIC_ADDR_UNDEF(vgic_cpu->rd_iodev.base_addr)) >> + return 0; >> + >> /* >> * We may be creating VCPUs before having set the base address for the >> * redistributor region, in which case we will come back to this >> -- >> 2.5.5 >> >