From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935019Ab3E2RvH (ORCPT ); Wed, 29 May 2013 13:51:07 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:31660 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934764Ab3E2Ru7 (ORCPT ); Wed, 29 May 2013 13:50:59 -0400 X-IronPort-AV: E=Sophos;i="4.87,765,1363132800"; d="scan'208";a="26711375" Date: Wed, 29 May 2013 18:50:41 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Stefano Stabellini CC: Konrad Rzeszutek Wilk , David Vrabel , "xen-devel@lists.xensource.com" , Feng Jin , Zhenzhong Duan , Yuval Shaia , "linux-kernel@vger.kernel.org" , Chien Yen , Ingo Molnar , "H. Peter Anvin" , Thomas Gleixner Subject: Re: [Xen-devel] [PATCH] xen: reuse the same pirq allocated when driver load first time In-Reply-To: Message-ID: References: <20130513182055.GC14177@phenom.dumpdata.com> <20130514142013.GA10173@konrad-lan.dumpdata.com> <5195944A.3050608@oracle.com> <20130520175706.GA27973@phenom.dumpdata.com> <20130520203855.GA30616@phenom.dumpdata.com> <519B474E.4000202@citrix.com> <20130521134059.GE492@phenom.dumpdata.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 21 May 2013, Stefano Stabellini wrote: > On Tue, 21 May 2013, Konrad Rzeszutek Wilk wrote: > > > Looking at the hypervisor code I couldn't see anything obviously wrong. > > > > I think the culprit is "physdev_unmap_pirq": > > > > if ( is_hvm_domain(d) ) > > { > > spin_lock(&d->event_lock); > > gdprintk(XENLOG_WARNING,"d%d, pirq: %d is %x %s, irq: %d\n", > > d->domain_id, pirq, domain_pirq_to_emuirq(d, pirq), > > domain_pirq_to_emuirq(d, pirq) == IRQ_UNBOUND ? "unbound" : "", > > domain_pirq_to_irq(d, pirq)); > > > > if ( domain_pirq_to_emuirq(d, pirq) != IRQ_UNBOUND ) > > ret = unmap_domain_pirq_emuirq(d, pirq); > > spin_unlock(&d->event_lock); > > if ( domid == DOMID_SELF || ret ) > > goto free_domain; > > > > It always tells me unbound: > > > > (XEN) physdev.c:237:d14 14, pirq: 54 is ffffffff > > (XEN) irq.c:1873:d14 14, nr_pirqs: 56 > > (XEN) physdev.c:237:d14 14, pirq: 53 is ffffffff > > (XEN) irq.c:1873:d14 14, nr_pirqs: 56 > > (XEN) physdev.c:237:d14 14, pirq: 52 is ffffffff > > (XEN) irq.c:1873:d14 14, nr_pirqs: 56 > > (XEN) physdev.c:237:d14 14, pirq: 51 is ffffffff > > (XEN) irq.c:1873:d14 14, nr_pirqs: 56 > > (XEN) physdev.c:237:d14 14, pirq: 50 is ffffffff > > (XEN) irq.c:1873:d14 14, nr_pirqs: 56 > > (a bit older debug code, so the 'unbound' does not show up here). > > > > Which means that the call to unmap_domain_pirq_emuirq does not happen. > > The checks in unmap_domain_pirq_emuirq also look to be depend > > on the code being IRQ_UNBOUND. > > > > In other words, all of that code looks to only clear things when > > they are !IRQ_UNBOUND. > > > > But the other logic (IRQ_UNBOUND) looks to be missing a removal > > in the radix tree: > > > > if ( emuirq != IRQ_PT ) > > radix_tree_delete(&d->arch.hvm_domain.emuirq_pirq, emuirq); > > > > And I think that is what is causing the leak - the radix tree > > needs to be pruned? Or perhaps the allocate_pirq should check > > the radix tree for IRQ_UNBOUND ones and re-use them? > > I think that you are looking in the wrong place. > The issue is that QEMU doesn't call pt_msi_disable in > pt_msgctrl_reg_write if (!val & PCI_MSI_FLAGS_ENABLE). > > The code above is correct as is because it is trying to handle emulated > IRQs and MSIs, not real passthrough MSIs. They latter are not added to > that radix tree, see physdev_hvm_map_pirq and physdev_map_pirq. This patch fixes the issue, I have only tested MSI (MSI-X completely untested). diff --git a/hw/pass-through.c b/hw/pass-through.c index 304c438..079e465 100644 --- a/hw/pass-through.c +++ b/hw/pass-through.c @@ -3866,7 +3866,11 @@ static int pt_msgctrl_reg_write(struct pt_dev *ptdev, ptdev->msi->flags |= PCI_MSI_FLAGS_ENABLE; } else - ptdev->msi->flags &= ~PCI_MSI_FLAGS_ENABLE; + { + if (ptdev->msi->flags & PT_MSI_MAPPED) { + pt_msi_disable(ptdev); + } + } /* pass through MSI_ENABLE bit when no MSI-INTx translation */ if (!ptdev->msi_trans_en) { @@ -4013,6 +4017,8 @@ static int pt_msixctrl_reg_write(struct pt_dev *ptdev, pt_disable_msi_translate(ptdev); } pt_msix_update(ptdev); + } else if (!(*value & PCI_MSIX_ENABLE) && ptdev->msix->enabled) { + pt_msix_delete(ptdev); } ptdev->msix->enabled = !!(*value & PCI_MSIX_ENABLE); diff --git a/hw/pt-msi.c b/hw/pt-msi.c index b03b989..65fa7d6 100644 --- a/hw/pt-msi.c +++ b/hw/pt-msi.c @@ -213,7 +213,8 @@ void pt_msi_disable(struct pt_dev *dev) out: /* clear msi info */ - dev->msi->flags &= ~(MSI_FLAG_UNINIT | PT_MSI_MAPPED | PCI_MSI_FLAGS_ENABLE); + dev->msi->flags &= ~(PT_MSI_MAPPED | PCI_MSI_FLAGS_ENABLE); + dev->msi->flags |= MSI_FLAG_UNINIT; dev->msi->pirq = -1; dev->msi_trans_en = 0; }