> -----Original Message----- > From: Eric Auger [mailto:eric.auger@xxxxxxxxxx] > Sent: Monday, July 06, 2015 7:20 PM > To: Wu, Feng; eric.auger@xxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; > kvmarm@xxxxxxxxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; > christoffer.dall@xxxxxxxxxx; marc.zyngier@xxxxxxx; > alex.williamson@xxxxxxxxxx; pbonzini@xxxxxxxxxx; avi.kivity@xxxxxxxxx; > mtosatti@xxxxxxxxxx; joro@xxxxxxxxxx; b.reynal@xxxxxxxxxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx; patches@xxxxxxxxxx > Subject: Re: [RFC 16/17] KVM: eventfd: add irq bypass consumer management > > Hi Feng, > On 07/06/2015 09:55 AM, Wu, Feng wrote: > > > > > >> -----Original Message----- > >> From: Eric Auger [mailto:eric.auger@xxxxxxxxxx] > >> Sent: Thursday, July 02, 2015 9:17 PM > >> To: eric.auger@xxxxxx; eric.auger@xxxxxxxxxx; > >> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; kvmarm@xxxxxxxxxxxxxxxxxxxxx; > >> kvm@xxxxxxxxxxxxxxx; christoffer.dall@xxxxxxxxxx; marc.zyngier@xxxxxxx; > >> alex.williamson@xxxxxxxxxx; pbonzini@xxxxxxxxxx; avi.kivity@xxxxxxxxx; > >> mtosatti@xxxxxxxxxx; Wu, Feng; joro@xxxxxxxxxx; > >> b.reynal@xxxxxxxxxxxxxxxxxxxxxx > >> Cc: linux-kernel@xxxxxxxxxxxxxxx; patches@xxxxxxxxxx > >> 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 <eric.auger@xxxxxxxxxx> > >> --- > >> 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 <linux/srcu.h> > >> #include <linux/slab.h> > >> #include <linux/seqlock.h> > >> +#include <linux/irqbypass.h> > >> #include <trace/events/kvm.h> > >> > >> #include <kvm/iodev.h> > >> @@ -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? I am fine with this! Thanks, Feng > > Thanks for spotting this. > > Eric > > > > > Thanks, > > Feng > > > > > >> } > >> } > >> > >> -- > >> 1.9.1 > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
