Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750871Ab3F0EBT (ORCPT ); Thu, 27 Jun 2013 00:01:19 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:22560 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750727Ab3F0EBS (ORCPT ); Thu, 27 Jun 2013 00:01:18 -0400 Message-ID: <51CBB908.1050909@oracle.com> Date: Thu, 27 Jun 2013 12:01:12 +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: <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> <51CA674B.3090807@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 Content-Length: 13096 Lines: 312 On 2013-06-27 02:08, Stefano Stabellini wrote: > On Wed, 26 Jun 2013, Zhenzhong Duan wrote: >> 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. > Yeah, but it shouldn't be already set in QEMU. In fact in QEMU > dev->msix->enabled is modified in pt_msixctrl_reg_write after calling to > pt_msix_update. It does. line 707, PCI_MSIX_FLAGS_MASKALL | PCI_MSIX_FLAGS_ENABLE is set this will set dev->msix->enabled first time line 722, PCI_MSIX_FLAGS_ENABLE set this trigger call of pt_msix_update then dev->msix->enabled was set a second time > I was assuming that you needed to add "|| entry->pirq == -1" because you > needed to pass the check: > > if ( !entry->flags ) > return 0; > > at the beginning of pt_msix_update_one. Am I getting it right? Right, as entry->pirq is set to -1 when driver unload. > If that is case that I thought that we just needed to make sure that > when ptdev->msix->enabled is still zero then we go through the test in > pt_msix_update_one. Where is the mistake? If you want to use dev->msix->enabled for checking, below patch could work. But in this case, dev->msix->enabled doesn't represent PCI_MSIX_ENABLE any more, but a combination of PCI_MSIX_ENABLE and ~PCI_MSIX_MASK zduan *********************************************************** diff -up ./hw/pass-through.c.old2 ./hw/pass-through.c --- ./hw/pass-through.c.old2 2013-06-27 11:05:30.000000000 +0800 +++ ./hw/pass-through.c 2013-06-27 11:07:35.000000000 +0800 @@ -4027,7 +4027,7 @@ static int pt_msixctrl_reg_write(struct pt_msix_disable(ptdev); } - ptdev->msix->enabled = !!(*value & PCI_MSIX_ENABLE); + ptdev->msix->enabled = (*value & PCI_MSIX_ENABLE) && !(*value & PCI_MSIX_MASK); return 0; } diff -up ./hw/pt-msi.c.old2 ./hw/pt-msi.c --- ./hw/pt-msi.c.old2 2013-06-27 11:26:12.000000000 +0800 +++ ./hw/pt-msi.c 2013-06-27 11:27:13.000000000 +0800 @@ -294,7 +294,7 @@ static int pt_msix_update_one(struct pt_ uint32_t gflags = __get_msi_gflags(entry->io_mem[2], gaddr); int ret; - if ( !entry->flags ) + if ( !entry->flags && dev->msix->enabled ) return 0; if (!gvec) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/