RE: [Xen-devel] pv-ops domU not working with MSI interrupts on Nehalem

["Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>]

Is the 07:0.0 your tachyon device? The VT-d fault is suspcious.
Also is it possible to share the xen output?

Thanks
--jyh

>-----Original Message-----
>From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
>[mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Bruce Edge
>Sent: Tuesday, September 28, 2010 7:54 AM
>To: Konrad Rzeszutek Wilk
>Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
>Subject: Re: [Xen-devel] pv-ops domU not working with MSI interrupts on Nehalem
>
>On Mon, Sep 27, 2010 at 12:54 PM, Konrad Rzeszutek Wilk
><konrad.wilk@xxxxxxxxxx> wrote:
>> On Mon, Sep 27, 2010 at 12:16:50PM -0700, Bruce Edge wrote:
>>> On Mon, Sep 27, 2010 at 10:24 AM, Konrad Rzeszutek Wilk
>>> <konrad.wilk@xxxxxxxxxx> wrote:
>>> >
>>> > On Mon, Sep 27, 2010 at 08:52:39AM -0700, Bruce Edge wrote:
>>> > > One of our developers who is working on a tachyon driver is
>>> > > complaining that the pvops domU kernel is not working for these MSI
>>> > > interrupts.
>>> > > This is using the current head of xen/2.6.32.x on both a single
>>> > > Nahelam 920 and a dual E5540. This behavior is consistent with Xen
>>> > > 4.0.1, 4.0.2.rc1-pre and 4.1.
>>> > >
>>> > > Here are his comments:
>>> > >
>>> > > - the driver has no problem to enable msi interrupt and request the
>>> > > interrupt through kernel functions pci_enable_msi & request_irq
>>> >
>>> > What shows up in the Xen console when you send the 'q' key? Does it
>>> > show that the vector is assigned to the appropiate guest?
>>>
>>> The Xen console q key shows that the domU is assigned:
>>>
>>> (XEN)     Interrupts { 32, 41-42, 47 }
>>
>> Aha!
>>
>>>
>>> but the domU thinks it has:
>>>
>>> 124/125/126/127
>>>
>>> Is there some mapping that's taking place, or is this plain wrong?
>>
>> That looks wrong. The IRQ numbers (even though they are MSI vectors) are
>> setup as IRQ numbers in the DomU guest. You should have seen
>>
>> 32:
>> 41:
>> 42:
>> 47:
>> in you /proc/interrupts on your DomU guest.
>>
>> I wonder what broke  - can you use
>git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
>> devel/xen-pcifront-0.5 (or pv/pcifront-2.6.32)?
>
>Please forgive the git ignorance.
>
>Is this the right syntax?
>
>git clone 
>git://git.kernel.org/pub/scm/linux/kernel/git/konrad:pv/pcifront-2.6.32
>linux-2.6.32-pv-pcifront
>
>Initialized empty Git repository in
>/import/kaan/bedge/src/xen/kernel/pv-ops/linux-2.6.32-pv-pcifront/.git/
>fatal: The remote end hung up unexpectedly
>
>Or:
>
> git clone  git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
>
>Initialized empty Git repository in
>/import/kaan/bedge/src/xen/kernel/pv-ops/xen/.git/
>remote: error: Could not read 59eab2f8f04147c5aadc99f2034ca7e5b81e890f
>remote: fatal: Failed to traverse parents of commit
>979e121cb348add17ed8171bf447b27a3a9d1be3
>remote: aborting due to possible repository corruption on the remote side.
>fatal: early EOF
>fatal: index-pack failed
>
>>
>> It has the latest pcifront driver but without the PVonHVM enhancments
>> so we can try to eliminate the PvONHVM logic out of the picture.
>>
>>>
>>> >
>>> > > - the interrupt does happen. But the interrupt service routine of
>>> > > tachyon driver doesn't detect any interrupt status related to this
>>> > > interrupt, which inhibits the tachyon chip from coming on-line. And
>>> > > there are high count of tachyon interrupt in /proc/interrupts
>>> >
>>> > Is it checking the PCI_STATUS_INTERRUPT or the appropiate register
>>> > in the MMIO BAR?
>>> >
>>>
>>> The driver would check the appropriate register (tachyon registers) in
>>> the MMIO to determine the source of interrupts.
>>
>> OK, so that isn't it. Is there anything at these vectors:
>> 7c, 7d, 7e, and 7f? When you use xen debug-keys 'i' or 'q' it should give you
>> an inkling what device this is set for.
>
>When I run a distro kernel in hvm mode, I get the expected irq mappings:
>
>'i' - Note 66 - 69
>(XEN)    IRQ:  66 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:3a
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=10:127(----),
>(XEN)    IRQ:  67 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:42
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=10:126(----),
>(XEN)    IRQ:  68 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:4a
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=10:125(----),
>(XEN)    IRQ:  69 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:52
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=10:124(----)
>
>
>'q'
>(XEN)     Interrupts { 32, 41-42, 47, 124-127 }
>
>
>The same data with pv-ops kernel shows:
>
>'i'
>IRQ numbers stop at 65, no 66 - 69 present:
>
>(XEN)    IRQ:  63 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:91
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=0:289(----),
>(XEN)    IRQ:  64 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:99
>type=PCI-MSI         status=00000002 mapped, unbound
>(XEN)    IRQ:  65 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:b1
>type=PCI-MSI         status=00000010 in-flight=0
>domain-list=0:287(----),
>(XEN) IO-APIC interrupt information:
>
>'q'
>(XEN)     Interrupts { 32, 41-42, 47 }
>
>>
>>>
>>> > >
>>> > > kaan-18-dpm:~# cat /proc/interrupts | grep TACH
>>> > >
>124:     760415          0          0          0          0
>    0
>>> > >          0          0          0          0          0
>      0
>>> > >     0          0  xen-pirq-pcifront-msi  HW_TACHYON
>>> > >
>125:     762234          0          0          0          0
>    0
>>> > >          0          0          0          0          0
>      0
>>> > >     0          0  xen-pirq-pcifront-msi  HW_TACHYON
>>> > >
>126:     764180          0          0          0          0
>    0
>>> > >          0          0          0          0          0
>      0
>>> > >     0          0  xen-pirq-pcifront-msi  HW_TACHYON
>>> > >
>127:     764164          0          0          0          0
>    0
>>> > >          0          0          0          0          0
>      0
>>> > >     0          0  xen-pirq-pcifront-msi  HW_TACHYON
>>> >
>>> > Can you provide the full dmesg output?
>>>
>>> Attached.
>>>
>>> Some possibly related messages on dom0 console:
>>>
>>> [ 1882.269778] pciback 0000:07:00.0: enabling device (0000 -> 0003)
>>> [ 1882.269800] xen: registering gsi 32 triggering 0 polarity 1
>>> [ 1882.269827] xen_allocate_pirq: returning irq 32 for gsi 32
>>> [ 1882.269834] xen: --> irq=32
>>> [ 1882.269841] Already setup the GSI :32
>>> [ 1882.269847] pciback 0000:07:00.0: PCI INT A -> GSI 32 (level, low) -> 
>>> IRQ 32
>>> [ 1882.269866] pciback 0000:07:00.0: setting latency timer to 64
>>> [ 1882.270463] pciback 0000:07:00.0: Driver tried to write to a
>>> read-only configuration space field at offset 0x62, size 2. This may
>>> be harmless, but if you have problems with your device:
>>
>> Uhhh, for that I think you need to do 'lspci -vvv -xxx -s 07:00.00'
>> to find out what is at the configuration space. You could enable
>> it using the permissive attribute.
>>
>>> [ 1882.270465] 1) see permissive attribute in sysfs
>>> [ 1882.270467] 2) report problems to the xen-devel mailing list along
>>> with details of your device obtained from lspci.
>>> [ 1882.270615]   alloc irq_desc for 478 on node 0
>>> [ 1882.270625]   alloc kstat_irqs on node 0
>>
>> So for 478: what do you see? xen-pciback I presume?
>>> [ 1882.348411] pciback 0000:07:00.1: enabling device (0000 -> 0003)
>>> [ 1882.348433] xen: registering gsi 42 triggering 0 polarity 1
>>> [ 1882.348440] xen_allocate_pirq: returning irq 42 for gsi 42
>>> [ 1882.348445] xen: --> irq=42
>>> [ 1882.348472] Already setup the GSI :42
>>> [ 1882.348479] pciback 0000:07:00.1: PCI INT B -> GSI 42 (level, low) -> 
>>> IRQ 42
>>> [ 1882.348497] pciback 0000:07:00.1: setting latency timer to 64
>>> [ 1882.349063] pciback 0000:07:00.1: Driver tried to write to a
>>> read-only configuration space field at offset 0x62, size 2. This may
>>> be harmless, but if you have problems with your device:
>>> [ 1882.349066] 1) see permissive attribute in sysfs
>>> [ 1882.349067] 2) report problems to the xen-devel mailing list along
>>> with details of your device obtained from lspci.
>>> [ 1882.349205]   alloc irq_desc for 477 on node 0
>>> [ 1882.349215]   alloc kstat_irqs on node 0
>>> [ 1882.402893] pciback 0000:07:00.2: enabling device (0000 -> 0003)
>>> [ 1882.402908] xen: registering gsi 47 triggering 0 polarity 1
>>> [ 1882.402913] xen_allocate_pirq: returning irq 47 for gsi 47
>>> [ 1882.402916] xen: --> irq=47
>>> [ 1882.402921] Already setup the GSI :47
>>> [ 1882.402925] pciback 0000:07:00.2: PCI INT C -> GSI 47 (level, low) -> 
>>> IRQ 47
>>> [ 1882.402938] pciback 0000:07:00.2: setting latency timer to 64
>>> [ 1882.403280] pciback 0000:07:00.2: Driver tried to write to a
>>> read-only configuration space field at offset 0x62, size 2. This may
>>> be harmless, but if you have problems with your device:
>>> [ 1882.403282] 1) see permissive attribute in sysfs
>>> [ 1882.403282] 2) report problems to the xen-devel mailing list along
>>> with details of your device obtained from lspci.
>>> [ 1882.403380]   alloc irq_desc for 476 on node 0
>>> [ 1882.403386]   alloc kstat_irqs on node 0
>>> (XEN) [VT-D]iommu.c:824: iommu_fault_status: Primary Pending Fault
>>> (XEN) [VT-D]iommu.c:799: DMAR:[DMA Write] Request device [07:00.0]
>>> fault addr e6f80000, iommu reg = ffff82c3fff57000
>>> (XEN) DMAR:[fault reason 05h] PTE Write access is not set
>>> (XEN) print_vtd_entries: iommu = ffff83019fffa370 bdf = 7:0.0 gmfn = e6f80
>>> (XEN)     root_entry = ffff83019ff70000
>>> (XEN)     root_entry[7] = 19cf52001
>>> (XEN)     context = ffff83019cf52000
>>> (XEN)     context[0] = 102_706dc005
>>> (XEN)     l4 = ffff8300706dc000
>>> (XEN)     l4_index = 0
>>> (XEN)     l4[0] = 706db003
>>> (XEN)     l3 = ffff8300706db000
>>> (XEN)     l3_index = 3
>>> (XEN)     l3[3] = 702b6003
>>> (XEN)     l2 = ffff8300702b6000
>>> (XEN)     l2_index = 137
>>> (XEN)     l2[137] = 0
>>> (XEN)     l2[137] not present
>>> (XEN) traps.c:466:d0 Unhandled nmi fault/trap [#2] on VCPU 0 [ec=0000]
>>
>> That is not good. What changed from your earlier emails that this was 
>> triggered?
>
>Nothing
>> Or was it triggered all along?
>
>Yes, I just included it for completeness
>
>> What happens if you run the system without the iommu enabled?
>
>Haven't tried yet. Will check that next.
>
>-Bruce
>
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