From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750967Ab3FZEAQ (ORCPT ); Wed, 26 Jun 2013 00:00:16 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:44251 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750712Ab3FZEAP (ORCPT ); Wed, 26 Jun 2013 00:00:15 -0400 Message-ID: <51CA674B.3090807@oracle.com> Date: Wed, 26 Jun 2013 12:00:11 +0800 From: Zhenzhong Duan Reply-To: zhenzhong.duan@oracle.com Organization: oracle User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: Stefano Stabellini CC: Konrad Rzeszutek Wilk , David Vrabel , "xen-devel@lists.xensource.com" , Feng Jin , Yuval Shaia , "linux-kernel@vger.kernel.org" , Chien Yen Subject: Re: [Xen-devel] [PATCH] xen: reuse the same pirq allocated when driver load first time References: <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> <51AECC3A.7060803@oracle.com> <51C26F98.8070103@oracle.com> <51C7F2FE.3090803@oracle.com> <51C92B8F.6010904@oracle.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2013-06-26 01:51, Stefano Stabellini wrote: > On Tue, 25 Jun 2013, DuanZhenzhong wrote: >> Stefano Stabellini wrote: >>> Trimming some of the people in CC >>> >>> On Mon, 24 Jun 2013, Zhenzhong Duan wrote: >>> >>>> On 2013-06-20 22:21, Stefano Stabellini wrote: >>>> >>>>> On Thu, 20 Jun 2013, Zhenzhong Duan wrote: >>>>> >>>>>> On 2013-06-05 20:50, Stefano Stabellini wrote: >>>>>> >>>>>>> On Wed, 5 Jun 2013, Zhenzhong Duan wrote: >>>>>>> >>>>>>>> Stefano Stabellini wrote: >>>>>>>> >>>>>>>> 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); >>>>>>>> Hi Stefano, >>>>>>>> I made a test with this patch, os reboot when driver reload. If >>>>>>>> use >>>>>>>> pt_msix_disable >>>>>>>> instead of pt_msix_delete, driver could be reloaded. >>>>>>>> But I still see some error in qemu.log and xen console. Seems four >>>>>>>> IRQs >>>>>>>> are not freed >>>>>>>> when unmap. >>>>>>>> --------------first load--------------------------- >>>>>>>> pt_msix_update_one: pt_msix_update_one requested pirq = 103 >>>>>>>> pt_msix_update_one: Update msix entry 0 with pirq 67 gvec 0 >>>>>>>> pt_msix_update_one: pt_msix_update_one requested pirq = 102 >>>>>>>> pt_msix_update_one: Update msix entry 1 with pirq 66 gvec 0 >>>>>>>> pt_msix_update_one: pt_msix_update_one requested pirq = 101 >>>>>>>> pt_msix_update_one: Update msix entry 2 with pirq 65 gvec 0 >>>>>>>> pt_msix_update_one: pt_msix_update_one requested pirq = 100 >>>>>>>> pt_msix_update_one: Update msix entry 3 with pirq 64 gvec 0 >>>>>>>> ------------- first unload--------------------------- >>>>>>>> pt_msix_disable: Unbind msix with pirq 67, gvec 0 >>>>>>>> pt_msix_disable: Unmap msix with pirq 67 >>>>>>>> pt_msix_disable: Error: Unmapping of MSI-X failed. [00:04.0] >>>>>>>> pt_msix_disable: Unbind msix with pirq 66, gvec 0 >>>>>>>> pt_msix_disable: Unmap msix with pirq 66 >>>>>>>> pt_msix_disable: Error: Unmapping of MSI-X failed. [00:04.0] >>>>>>>> pt_msix_disable: Unbind msix with pirq 65, gvec 0 >>>>>>>> pt_msix_disable: Unmap msix with pirq 65 >>>>>>>> pt_msix_disable: Error: Unmapping of MSI-X failed. [00:04.0] >>>>>>>> pt_msix_disable: Unbind msix with pirq 64, gvec 0 >>>>>>>> pt_msix_disable: Unmap msix with pirq 64 >>>>>>>> pt_msix_disable: Error: Unmapping of MSI-X failed. [00:04.0] >>>>>>>> >>>>>>> Can you add some printks in Xen (the hypercall name is >>>>>>> PHYSDEVOP_unmap_pirq) to figure out exactly why they are failing? >>>>>>> >>>>>> Did some test, domain_pirq_to_emuirq(d, unmap->pirq) = IRQ_UNBOUND in >>>>>> physdev_unmap_pirq. >>>>>> >>>>> That means that Linux didn't call irq_enable on the MSI-X in question: >>>>> >>>>> irq_enable -> __startup_pirq -> EVTCHNOP_bind_pirq >>>>> >>>>> EVTCHNOP_bind_pirq is implemented by evtchn_bind_pirq in Xen and calls >>>>> map_domain_emuirq_pirq, so domain_pirq_to_emuirq(d, unmap->pirq) should >>>>> be IRQ_PT. >>>>> >>>>> I don't know if that's a normal condition, but in any case it should >>>>> not create any problems to physdev_unmap_pirq, in fact the folloing >>>>> check: >>>>> >>>>> if ( domid == DOMID_SELF || ret ) >>>>> goto free_domain; >>>>> >>>>> should fail so Xen should continue and execute unmap_domain_pirq. That's >>>>> what we want. >>>>> >>>> From linux side, request_irq-> request_threaded_irq-> __setup_irq-> >>>> irq_startup-> startup_pirq-> EVTCHNOP_bind_pirq >>>> If irq_enable isn't called, how does the driver receive interrupt, I did >>>> see >>>> four interrupts in /proc/interrupt and driver works ok. >>>> >>> Good to know >>> >>> >>>> Could you have a look if there is something wrong in xen side of clearing >>>> the >>>> mapping? >>>> >>> What I am saying is that the error you are getting: >>> >>> pt_msix_disable: Unbind msix with pirq 67, gvec 0 >>> pt_msix_disable: Unmap msix with pirq 67 >>> pt_msix_disable: Error: Unmapping of MSI-X failed. [00:04.0] >>> >>> cannot be caused by domain_pirq_to_emuirq(d, pirq) returning >>> IRQ_UNBOUND. >>> So, why are you getting this error? What is failing? >>> I am ready to believe the problem is in Xen but Without understanding >>> why you are getting the error it's hard to find a solution. >>> >> I found the reason, you are looking at xen-unstable, I was working with >> 4.1.30-OVM, it has patch of CVE-2012-4536 / XSA-21. >> That patch set ret to -EINVAL initially. After remove that line, unmap >> succeed. >> But we still need below patch to let driver reload succeed everytime. Without >> that, 1st reload failed, 2nd succeed, 3 failed, ... >> >> diff -up --new-file ./hw/pt-msi.c.old1 ./hw/pt-msi.c >> --- ./hw/pt-msi.c.old1 2013-06-26 01:36:08.000000000 +0800 >> +++ ./hw/pt-msi.c 2013-06-26 01:37:41.000000000 +0800 >> @@ -469,7 +469,7 @@ static void pci_msix_writel(void *opaque >> return; >> } >> >> - if ( offset != 3 && entry->io_mem[offset] != val ) >> + if ( offset != 3 && (entry->io_mem[offset] != val || entry->pirq == -1)) >> entry->flags = 1; >> entry->io_mem[offset] = val; > Interesting. I don't think this is the proper fix though. > Does the appended patch change anything? > > diff --git a/hw/pt-msi.c b/hw/pt-msi.c > index 71fa6f0..cd5d9c7 100644 > --- a/hw/pt-msi.c > +++ b/hw/pt-msi.c > @@ -302,7 +302,7 @@ static int pt_msix_update_one(struct pt_dev *dev, int entry_nr) > uint32_t gflags = __get_msi_gflags(entry->io_mem[2], gaddr); > int ret; > > - if ( !entry->flags ) > + if ( !entry->flags && ptdev->msix->enabled ) > return 0; > > if (!gvec) { Tested, not work. If you look at msix_capability_init in kernel, line 707,722, dev->msix->enabled is already set when pt_msix_update is called. zduan