From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: Re: [RFC 16/17] KVM: eventfd: add irq bypass consumer management Date: Mon, 06 Jul 2015 13:19:46 +0200 Message-ID: <559A6452.7030303@linaro.org> References: <1435843047-6327-1-git-send-email-eric.auger@linaro.org> <1435843047-6327-17-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 276FC57633 for ; Mon, 6 Jul 2015 07:08:43 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jkeExXrD74cS for ; Mon, 6 Jul 2015 07:08:41 -0400 (EDT) Received: from mail-wg0-f45.google.com (mail-wg0-f45.google.com [74.125.82.45]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 0C32E57632 for ; Mon, 6 Jul 2015 07:08:40 -0400 (EDT) Received: by wgqq4 with SMTP id q4so137411529wgq.1 for ; Mon, 06 Jul 2015 04:20:07 -0700 (PDT) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: "Wu, Feng" , "eric.auger@st.com" , "linux-arm-kernel@lists.infradead.org" , "kvmarm@lists.cs.columbia.edu" , "kvm@vger.kernel.org" , "christoffer.dall@linaro.org" , "marc.zyngier@arm.com" , "alex.williamson@redhat.com" , "pbonzini@redhat.com" , "avi.kivity@gmail.com" , "mtosatti@redhat.com" , "joro@8bytes.org" , "b.reynal@virtualopensystems.com" Cc: "linux-kernel@vger.kernel.org" , "patches@linaro.org" List-Id: kvmarm@lists.cs.columbia.edu Hi Feng, On 07/06/2015 09:55 AM, Wu, Feng wrote: > > >> -----Original Message----- >> From: Eric Auger [mailto:eric.auger@linaro.org] >> Sent: Thursday, July 02, 2015 9:17 PM >> To: eric.auger@st.com; eric.auger@linaro.org; >> linux-arm-kernel@lists.infradead.org; kvmarm@lists.cs.columbia.edu; >> kvm@vger.kernel.org; christoffer.dall@linaro.org; marc.zyngier@arm.com; >> alex.williamson@redhat.com; pbonzini@redhat.com; avi.kivity@gmail.com; >> mtosatti@redhat.com; Wu, Feng; joro@8bytes.org; >> b.reynal@virtualopensystems.com >> Cc: linux-kernel@vger.kernel.org; patches@linaro.org >> Subject: [RFC 16/17] KVM: eventfd: add irq bypass consumer management >> >> This patch adds the registration/unregistration of an >> irq_bypass_consumer on irqfd assignment/deassignment. >> >> Signed-off-by: Eric Auger >> --- >> virt/kvm/eventfd.c | 22 +++++++++++++++++++--- >> 1 file changed, 19 insertions(+), 3 deletions(-) >> >> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c >> index f3da161..425a47b 100644 >> --- a/virt/kvm/eventfd.c >> +++ b/virt/kvm/eventfd.c >> @@ -34,6 +34,7 @@ >> #include >> #include >> #include >> +#include >> #include >> >> #include >> @@ -93,6 +94,7 @@ struct _irqfd { >> struct list_head list; >> poll_table pt; >> struct work_struct shutdown; >> + struct irq_bypass_consumer *cons; >> }; >> >> static struct workqueue_struct *irqfd_cleanup_wq; >> @@ -429,7 +431,21 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd >> *args) >> */ >> fdput(f); >> >> - /* irq_bypass_register_consumer(); */ >> + irqfd->cons = kzalloc(sizeof(struct irq_bypass_consumer), >> + GFP_KERNEL); >> + if (!irqfd->cons) { >> + ret = -ENOMEM; >> + goto fail; >> + } >> + irqfd->cons->token = (void *)irqfd->eventfd; >> + irqfd->cons->gsi = irqfd->gsi; >> + irqfd->cons->kvm = kvm; >> + irqfd->cons->add_producer = kvm_arch_add_producer; >> + irqfd->cons->del_producer = kvm_arch_del_producer; >> + irqfd->cons->stop_consumer = kvm_arch_stop_consumer; >> + irqfd->cons->resume_consumer = kvm_arch_resume_consumer; >> + ret = irq_bypass_register_consumer(irqfd->cons); >> + WARN_ON(ret); >> >> return 0; >> >> @@ -530,8 +546,6 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd >> *args) >> struct _irqfd *irqfd, *tmp; >> struct eventfd_ctx *eventfd; >> >> - /* irq_bypass_unregister_consumer() */ >> - >> eventfd = eventfd_ctx_fdget(args->fd); >> if (IS_ERR(eventfd)) >> return PTR_ERR(eventfd); >> @@ -550,6 +564,8 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd >> *args) >> irqfd->irq_entry.type = 0; >> write_seqcount_end(&irqfd->irq_entry_sc); >> irqfd_deactivate(irqfd); >> + irq_bypass_unregister_consumer(irqfd->cons); >> + kfree(irqfd->cons); > > There may be an issue here. 'irqfd' is freed in irqfd_deactivate() --> ... --.>irqfd_shutdown(), > and irqfd_deactivate() can be called in the other two places below: > - irqfd_wakeup() > - kvm_irqfd_release() > I think we also need to call irq_bypass_unregister_consumer() there, right? yes you're right. what about doing the unregistration in irqfd_shutdown then? Thanks for spotting this. Eric > > Thanks, > Feng > > >> } >> } >> >> -- >> 1.9.1 >