Porblem with disabling and then re-enabling a PT device in Windows

Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

Hi All,

(This is a continuation to my previous mail, but since it looks like a
different problem - i decided to open a new thread for it)

----
Problem Description:
----
I am doing pass-through of an Intel wireless LAN device to a Windows
XP domU (my machine is Dell e6400), and it looks like it's working ok.
Then, i disable the device using Windows device manager, and the
device is now disabled, after that i re-enable the device, and Windows
re-enables the device correctly. However, the wlan device seems to
malfunction (it can't turn on the WiFi of the computer), and can't
connect to wireless networks.
I tried it, both with MSI translation on, and with MSI translation off
- it doesn't matter.

----
My analysis:
----
1) Well, taking a look at the real PCI config space, before disable
and after the (last) enable, shows that the difference is at the Intx
bit (read-only bit 3 at status register (offset 0x6) at the PCI config
space). Before disable, that bit was 0, and after the last enable that
bit was 1.
This, according to my understanding, means that the device is
asserting it's IntX , and probably waiting for someone to handle it,
no?

2) When i tried to track when did this bit was changed - i added a
code which in every PCI config read, checks if that bit was changed -
and added a print when it changed. The proper lines in the qemu log
looks like this:
...
pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
...

This implies that the bit was changed, about the same time that
Windows tried to start using it (because, i assume that it tried using
it, just after questioning the ACPI for the existence of the device).
No?


Can someone help me with this?

(BTW - i am using Xen 3.4)

Tom

RE: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Kamala Narasimhan]

There is a chance pciback is changing the bit you are referring to.  To confirm that, just for testing purpose you might want to avoid FLR for that device or simply not build pciback or comment out relevant code in that module whichever is easier and see if that helps.  If it does, you can then look into fixing the problem the right way.

Kamala

> -----Original Message-----
> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
> Sent: Wednesday, November 25, 2009 8:09 AM
> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
> Subject: [Xci-devel] Porblem with disabling and then re-enabling a PT
> device in Windows
> 
> Hi All,
> 
> (This is a continuation to my previous mail, but since it looks like a
> different problem - i decided to open a new thread for it)
> 
> ----
> Problem Description:
> ----
> I am doing pass-through of an Intel wireless LAN device to a Windows
> XP domU (my machine is Dell e6400), and it looks like it's working ok.
> Then, i disable the device using Windows device manager, and the
> device is now disabled, after that i re-enable the device, and Windows
> re-enables the device correctly. However, the wlan device seems to
> malfunction (it can't turn on the WiFi of the computer), and can't
> connect to wireless networks.
> I tried it, both with MSI translation on, and with MSI translation off
> - it doesn't matter.
> 
> ----
> My analysis:
> ----
> 1) Well, taking a look at the real PCI config space, before disable
> and after the (last) enable, shows that the difference is at the Intx
> bit (read-only bit 3 at status register (offset 0x6) at the PCI config
> space). Before disable, that bit was 0, and after the last enable that
> bit was 1.
> This, according to my understanding, means that the device is
> asserting it's IntX , and probably waiting for someone to handle it,
> no?
> 
> 2) When i tried to track when did this bit was changed - i added a
> code which in every PCI config read, checks if that bit was changed -
> and added a print when it changed. The proper lines in the qemu log
> looks like this:
> ...
> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
> pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
> ...
> 
> This implies that the bit was changed, about the same time that
> Windows tried to start using it (because, i assume that it tried using
> it, just after questioning the ACPI for the existence of the device).
> No?
> 
> 
> Can someone help me with this?
> 
> (BTW - i am using Xen 3.4)
> 
> Tom
> 
> _______________________________________________
> Xci-devel mailing list
> Xci-devel@lists.xensource.com
> http://lists.xensource.com/mailman/listinfo/xci-devel

Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

I am not sure i undertand how to test it...
1) Avoid doing FLR for the device - isn';t that done only when
building the domain? does that happen when i disable the device in
domU?
2) Don't build pciback - and then, i won't bind the wlan device to
pciback? and change the xend scripts which check for it?
3) Comment out the relevant code - which code??

I also don't understand, how could it be that the pciback device is
"messing" with it? isn't it supposed to be in-active when the device
is being used in PT?

Tom

On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
<Kamala.Narasimhan@citrix.com> wrote:
> There is a chance pciback is changing the bit you are referring to.  To confirm that, just for testing purpose you might want to avoid FLR for that device or simply not build pciback or comment out relevant code in that module whichever is easier and see if that helps.  If it does, you can then look into fixing the problem the right way.
>
> Kamala
>
>> -----Original Message-----
>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>> Sent: Wednesday, November 25, 2009 8:09 AM
>> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>> Subject: [Xci-devel] Porblem with disabling and then re-enabling a PT
>> device in Windows
>>
>> Hi All,
>>
>> (This is a continuation to my previous mail, but since it looks like a
>> different problem - i decided to open a new thread for it)
>>
>> ----
>> Problem Description:
>> ----
>> I am doing pass-through of an Intel wireless LAN device to a Windows
>> XP domU (my machine is Dell e6400), and it looks like it's working ok.
>> Then, i disable the device using Windows device manager, and the
>> device is now disabled, after that i re-enable the device, and Windows
>> re-enables the device correctly. However, the wlan device seems to
>> malfunction (it can't turn on the WiFi of the computer), and can't
>> connect to wireless networks.
>> I tried it, both with MSI translation on, and with MSI translation off
>> - it doesn't matter.
>>
>> ----
>> My analysis:
>> ----
>> 1) Well, taking a look at the real PCI config space, before disable
>> and after the (last) enable, shows that the difference is at the Intx
>> bit (read-only bit 3 at status register (offset 0x6) at the PCI config
>> space). Before disable, that bit was 0, and after the last enable that
>> bit was 1.
>> This, according to my understanding, means that the device is
>> asserting it's IntX , and probably waiting for someone to handle it,
>> no?
>>
>> 2) When i tried to track when did this bit was changed - i added a
>> code which in every PCI config read, checks if that bit was changed -
>> and added a print when it changed. The proper lines in the qemu log
>> looks like this:
>> ...
>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
>> pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
>> ...
>>
>> This implies that the bit was changed, about the same time that
>> Windows tried to start using it (because, i assume that it tried using
>> it, just after questioning the ACPI for the existence of the device).
>> No?
>>
>>
>> Can someone help me with this?
>>
>> (BTW - i am using Xen 3.4)
>>
>> Tom
>>
>> _______________________________________________
>> Xci-devel mailing list
>> Xci-devel@lists.xensource.com
>> http://lists.xensource.com/mailman/listinfo/xci-devel
>

RE: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Kamala Narasimhan]

I shouldn't have suggested that you build without pciback; I got carried away trying to make it simple for you :-); Obviously you would need it and I should have stopped with suggesting that you tweak it.

Here is the thought process that led to my suggestion -

Clearly, that bit is getting changed as indicated in your log.  It is unlikely that the guest is triggering that change which makes pciback a potential candidate to suspect as it does change pci configuration space bits.  I need to add some tracing and look at the path of execution to answer some of your specific questions accurately and I won't be able to do that right now but I can give some context to help you based on what I have experienced in comparable situation and based on that I would say pciback is one place to suspect.  To be a bit more specific I would say look into pciback_enable_msi/pciback_disable_msi code, add some tracing there, observe whether or not that code path is taken when the device is disabled/reenabled within guest etc.  To reiterate, these are mere suggestions but looks plausible based on prior observations.

Kamala

> -----Original Message-----
> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
> Sent: Wednesday, November 25, 2009 9:22 AM
> To: Kamala Narasimhan
> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
> Subject: Re: [Xci-devel] Porblem with disabling and then re-enabling a
> PT device in Windows
> 
> I am not sure i undertand how to test it...
> 1) Avoid doing FLR for the device - isn';t that done only when
> building the domain? does that happen when i disable the device in
> domU?
> 2) Don't build pciback - and then, i won't bind the wlan device to
> pciback? and change the xend scripts which check for it?
> 3) Comment out the relevant code - which code??
> 
> I also don't understand, how could it be that the pciback device is
> "messing" with it? isn't it supposed to be in-active when the device
> is being used in PT?
> 
> Tom
> 
> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
> <Kamala.Narasimhan@citrix.com> wrote:
> > There is a chance pciback is changing the bit you are referring
> to.  To confirm that, just for testing purpose you might want to avoid
> FLR for that device or simply not build pciback or comment out relevant
> code in that module whichever is easier and see if that helps.  If it
> does, you can then look into fixing the problem the right way.
> >
> > Kamala
> >
> >> -----Original Message-----
> >> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
> >> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
> >> Sent: Wednesday, November 25, 2009 8:09 AM
> >> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
> >> Subject: [Xci-devel] Porblem with disabling and then re-enabling a
> PT
> >> device in Windows
> >>
> >> Hi All,
> >>
> >> (This is a continuation to my previous mail, but since it looks like
> a
> >> different problem - i decided to open a new thread for it)
> >>
> >> ----
> >> Problem Description:
> >> ----
> >> I am doing pass-through of an Intel wireless LAN device to a Windows
> >> XP domU (my machine is Dell e6400), and it looks like it's working
> ok.
> >> Then, i disable the device using Windows device manager, and the
> >> device is now disabled, after that i re-enable the device, and
> Windows
> >> re-enables the device correctly. However, the wlan device seems to
> >> malfunction (it can't turn on the WiFi of the computer), and can't
> >> connect to wireless networks.
> >> I tried it, both with MSI translation on, and with MSI translation
> off
> >> - it doesn't matter.
> >>
> >> ----
> >> My analysis:
> >> ----
> >> 1) Well, taking a look at the real PCI config space, before disable
> >> and after the (last) enable, shows that the difference is at the
> Intx
> >> bit (read-only bit 3 at status register (offset 0x6) at the PCI
> config
> >> space). Before disable, that bit was 0, and after the last enable
> that
> >> bit was 1.
> >> This, according to my understanding, means that the device is
> >> asserting it's IntX , and probably waiting for someone to handle it,
> >> no?
> >>
> >> 2) When i tried to track when did this bit was changed - i added a
> >> code which in every PCI config read, checks if that bit was changed
> -
> >> and added a print when it changed. The proper lines in the qemu log
> >> looks like this:
> >> ...
> >> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
> >> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
> >> pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
> >> ...
> >>
> >> This implies that the bit was changed, about the same time that
> >> Windows tried to start using it (because, i assume that it tried
> using
> >> it, just after questioning the ACPI for the existence of the device).
> >> No?
> >>
> >>
> >> Can someone help me with this?
> >>
> >> (BTW - i am using Xen 3.4)
> >>
> >> Tom
> >>
> >> _______________________________________________
> >> Xci-devel mailing list
> >> Xci-devel@lists.xensource.com
> >> http://lists.xensource.com/mailman/listinfo/xci-devel
> >

Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

Well, i just performed some tests, and it doesn't look like the
disable_msi/enable_msi functions in pciback are being called at all
(moreover, not in the disable-enable from domU Windows XP), so i don't
think it's related.
Also, since when, a config space write from a guest domU triggers code
in the pciback?

I think that it's not the problem here...
Maybe someone from the XCI can shed some light here, and tell us how
they solve it (or not)? since their code should run on the same Dell
machines, no?

On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
<Kamala.Narasimhan@citrix.com> wrote:
> I shouldn't have suggested that you build without pciback; I got carried away trying to make it simple for you :-); Obviously you would need it and I should have stopped with suggesting that you tweak it.
>
> Here is the thought process that led to my suggestion -
>
> Clearly, that bit is getting changed as indicated in your log.  It is unlikely that the guest is triggering that change which makes pciback a potential candidate to suspect as it does change pci configuration space bits.  I need to add some tracing and look at the path of execution to answer some of your specific questions accurately and I won't be able to do that right now but I can give some context to help you based on what I have experienced in comparable situation and based on that I would say pciback is one place to suspect.  To be a bit more specific I would say look into pciback_enable_msi/pciback_disable_msi code, add some tracing there, observe whether or not that code path is taken when the device is disabled/reenabled within guest etc.  To reiterate, these are mere suggestions but looks plausible based on prior observations.
>
> Kamala
>
>> -----Original Message-----
>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>> Sent: Wednesday, November 25, 2009 9:22 AM
>> To: Kamala Narasimhan
>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>> Subject: Re: [Xci-devel] Porblem with disabling and then re-enabling a
>> PT device in Windows
>>
>> I am not sure i undertand how to test it...
>> 1) Avoid doing FLR for the device - isn';t that done only when
>> building the domain? does that happen when i disable the device in
>> domU?
>> 2) Don't build pciback - and then, i won't bind the wlan device to
>> pciback? and change the xend scripts which check for it?
>> 3) Comment out the relevant code - which code??
>>
>> I also don't understand, how could it be that the pciback device is
>> "messing" with it? isn't it supposed to be in-active when the device
>> is being used in PT?
>>
>> Tom
>>
>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>> <Kamala.Narasimhan@citrix.com> wrote:
>> > There is a chance pciback is changing the bit you are referring
>> to.  To confirm that, just for testing purpose you might want to avoid
>> FLR for that device or simply not build pciback or comment out relevant
>> code in that module whichever is easier and see if that helps.  If it
>> does, you can then look into fixing the problem the right way.
>> >
>> > Kamala
>> >
>> >> -----Original Message-----
>> >> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>> >> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>> >> Sent: Wednesday, November 25, 2009 8:09 AM
>> >> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>> >> Subject: [Xci-devel] Porblem with disabling and then re-enabling a
>> PT
>> >> device in Windows
>> >>
>> >> Hi All,
>> >>
>> >> (This is a continuation to my previous mail, but since it looks like
>> a
>> >> different problem - i decided to open a new thread for it)
>> >>
>> >> ----
>> >> Problem Description:
>> >> ----
>> >> I am doing pass-through of an Intel wireless LAN device to a Windows
>> >> XP domU (my machine is Dell e6400), and it looks like it's working
>> ok.
>> >> Then, i disable the device using Windows device manager, and the
>> >> device is now disabled, after that i re-enable the device, and
>> Windows
>> >> re-enables the device correctly. However, the wlan device seems to
>> >> malfunction (it can't turn on the WiFi of the computer), and can't
>> >> connect to wireless networks.
>> >> I tried it, both with MSI translation on, and with MSI translation
>> off
>> >> - it doesn't matter.
>> >>
>> >> ----
>> >> My analysis:
>> >> ----
>> >> 1) Well, taking a look at the real PCI config space, before disable
>> >> and after the (last) enable, shows that the difference is at the
>> Intx
>> >> bit (read-only bit 3 at status register (offset 0x6) at the PCI
>> config
>> >> space). Before disable, that bit was 0, and after the last enable
>> that
>> >> bit was 1.
>> >> This, according to my understanding, means that the device is
>> >> asserting it's IntX , and probably waiting for someone to handle it,
>> >> no?
>> >>
>> >> 2) When i tried to track when did this bit was changed - i added a
>> >> code which in every PCI config read, checks if that bit was changed
>> -
>> >> and added a print when it changed. The proper lines in the qemu log
>> >> looks like this:
>> >> ...
>> >> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>> >> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
>> >> pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
>> >> ...
>> >>
>> >> This implies that the bit was changed, about the same time that
>> >> Windows tried to start using it (because, i assume that it tried
>> using
>> >> it, just after questioning the ACPI for the existence of the device).
>> >> No?
>> >>
>> >>
>> >> Can someone help me with this?
>> >>
>> >> (BTW - i am using Xen 3.4)
>> >>
>> >> Tom
>> >>
>> >> _______________________________________________
>> >> Xci-devel mailing list
>> >> Xci-devel@lists.xensource.com
>> >> http://lists.xensource.com/mailman/listinfo/xci-devel
>> >
>

Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

After digging more into this problem, i found out that the problem is
because the interrupt generated on the wlan device, isn't being
transfered to the domain, for some reason, after the device was
re-enablked in Windows.
I saw that, by connecting to the xen console, and then clicking 'i',
and i got the following lines:
...
(XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
in-flight=1 domain-list=0: 17(----),3: 17(---M),
...
(XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
dest_mode=logical, delivery_status=1, polarity=1, irr=1,
trigger=level, mask=0
....

You can see, that the interrupt 17, which is in my Windows domU, was
generated, but still weren't injected to the CPU (the 'irr' is 1). So,
i guess that this is what is causing the problem.
Now, the only issue left, is why the hell, the interrupt isn't being
injected to the domain?

Has anyone has any idea about it?

On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg <tom.rotenberg@gmail.com> wrote:
> Well, i just performed some tests, and it doesn't look like the
> disable_msi/enable_msi functions in pciback are being called at all
> (moreover, not in the disable-enable from domU Windows XP), so i don't
> think it's related.
> Also, since when, a config space write from a guest domU triggers code
> in the pciback?
>
> I think that it's not the problem here...
> Maybe someone from the XCI can shed some light here, and tell us how
> they solve it (or not)? since their code should run on the same Dell
> machines, no?
>
> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
> <Kamala.Narasimhan@citrix.com> wrote:
>> I shouldn't have suggested that you build without pciback; I got carried away trying to make it simple for you :-); Obviously you would need it and I should have stopped with suggesting that you tweak it.
>>
>> Here is the thought process that led to my suggestion -
>>
>> Clearly, that bit is getting changed as indicated in your log.  It is unlikely that the guest is triggering that change which makes pciback a potential candidate to suspect as it does change pci configuration space bits.  I need to add some tracing and look at the path of execution to answer some of your specific questions accurately and I won't be able to do that right now but I can give some context to help you based on what I have experienced in comparable situation and based on that I would say pciback is one place to suspect.  To be a bit more specific I would say look into pciback_enable_msi/pciback_disable_msi code, add some tracing there, observe whether or not that code path is taken when the device is disabled/reenabled within guest etc.  To reiterate, these are mere suggestions but looks plausible based on prior observations.
>>
>> Kamala
>>
>>> -----Original Message-----
>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>> To: Kamala Narasimhan
>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>> Subject: Re: [Xci-devel] Porblem with disabling and then re-enabling a
>>> PT device in Windows
>>>
>>> I am not sure i undertand how to test it...
>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>> building the domain? does that happen when i disable the device in
>>> domU?
>>> 2) Don't build pciback - and then, i won't bind the wlan device to
>>> pciback? and change the xend scripts which check for it?
>>> 3) Comment out the relevant code - which code??
>>>
>>> I also don't understand, how could it be that the pciback device is
>>> "messing" with it? isn't it supposed to be in-active when the device
>>> is being used in PT?
>>>
>>> Tom
>>>
>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>> <Kamala.Narasimhan@citrix.com> wrote:
>>> > There is a chance pciback is changing the bit you are referring
>>> to.  To confirm that, just for testing purpose you might want to avoid
>>> FLR for that device or simply not build pciback or comment out relevant
>>> code in that module whichever is easier and see if that helps.  If it
>>> does, you can then look into fixing the problem the right way.
>>> >
>>> > Kamala
>>> >
>>> >> -----Original Message-----
>>> >> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>> >> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>> >> Sent: Wednesday, November 25, 2009 8:09 AM
>>> >> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>> >> Subject: [Xci-devel] Porblem with disabling and then re-enabling a
>>> PT
>>> >> device in Windows
>>> >>
>>> >> Hi All,
>>> >>
>>> >> (This is a continuation to my previous mail, but since it looks like
>>> a
>>> >> different problem - i decided to open a new thread for it)
>>> >>
>>> >> ----
>>> >> Problem Description:
>>> >> ----
>>> >> I am doing pass-through of an Intel wireless LAN device to a Windows
>>> >> XP domU (my machine is Dell e6400), and it looks like it's working
>>> ok.
>>> >> Then, i disable the device using Windows device manager, and the
>>> >> device is now disabled, after that i re-enable the device, and
>>> Windows
>>> >> re-enables the device correctly. However, the wlan device seems to
>>> >> malfunction (it can't turn on the WiFi of the computer), and can't
>>> >> connect to wireless networks.
>>> >> I tried it, both with MSI translation on, and with MSI translation
>>> off
>>> >> - it doesn't matter.
>>> >>
>>> >> ----
>>> >> My analysis:
>>> >> ----
>>> >> 1) Well, taking a look at the real PCI config space, before disable
>>> >> and after the (last) enable, shows that the difference is at the
>>> Intx
>>> >> bit (read-only bit 3 at status register (offset 0x6) at the PCI
>>> config
>>> >> space). Before disable, that bit was 0, and after the last enable
>>> that
>>> >> bit was 1.
>>> >> This, according to my understanding, means that the device is
>>> >> asserting it's IntX , and probably waiting for someone to handle it,
>>> >> no?
>>> >>
>>> >> 2) When i tried to track when did this bit was changed - i added a
>>> >> code which in every PCI config read, checks if that bit was changed
>>> -
>>> >> and added a print when it changed. The proper lines in the qemu log
>>> >> looks like this:
>>> >> ...
>>> >> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>>> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>> >> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>> >> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW: 0x18
>>> >> pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086 len=2
>>> >> ...
>>> >>
>>> >> This implies that the bit was changed, about the same time that
>>> >> Windows tried to start using it (because, i assume that it tried
>>> using
>>> >> it, just after questioning the ACPI for the existence of the device).
>>> >> No?
>>> >>
>>> >>
>>> >> Can someone help me with this?
>>> >>
>>> >> (BTW - i am using Xen 3.4)
>>> >>
>>> >> Tom
>>> >>
>>> >> _______________________________________________
>>> >> Xci-devel mailing list
>>> >> Xci-devel@lists.xensource.com
>>> >> http://lists.xensource.com/mailman/listinfo/xci-devel
>>> >
>>
>

RE: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Jiang, Yunhong]

xen-devel-bounces@lists.xensource.com wrote:
> After digging more into this problem, i found out that the problem is
> because the interrupt generated on the wlan device, isn't being
> transfered to the domain, for some reason, after the device was
> re-enablked in Windows. I saw that, by connecting to the xen console,
> and then clicking 'i', and i got the following lines:
> ...
> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
> in-flight=1 domain-list=0: 17(----),3: 17(---M),
> ...
> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
> trigger=level, mask=0 ....
> 
> You can see, that the interrupt 17, which is in my Windows domU, was
> generated, but still weren't injected to the CPU (the 'irr' is 1). So,
> i guess that this is what is causing the problem.
> Now, the only issue left, is why the hell, the interrupt isn't being
> injected to the domain? 

I assume you are using ack_type_new on your system, am I right?
Usually it means guest has not EOI the interrupt, so that host has no chance to EOI the physical IOAPIC. Can you check the virtual Local APIC/IOAPIC for the guest to see if we have any finding?
BTW, does it happen everytime?

--jyh

> 
> Has anyone has any idea about it?
> 
> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
> <tom.rotenberg@gmail.com> wrote:
>> Well, i just performed some tests, and it doesn't look like the
>> disable_msi/enable_msi functions in pciback are being called at all
>> (moreover, not in the disable-enable from domU Windows XP), so i
>> don't think it's related. Also, since when, a config space write
>> from a guest domU triggers code in the pciback? 
>> 
>> I think that it's not the problem here...
>> Maybe someone from the XCI can shed some light here, and tell us how
>> they solve it (or not)? since their code should run on the same Dell
>> machines, no? 
>> 
>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>> <Kamala.Narasimhan@citrix.com> wrote:
>>> I shouldn't have suggested that you build without pciback;
> I got carried away trying to make it simple for you :-);
> Obviously you would need it and I should have stopped with
> suggesting that you tweak it.
>>> 
>>> Here is the thought process that led to my suggestion -
>>> 
>>> Clearly, that bit is getting changed as indicated in your
> log.  It is unlikely that the guest is triggering that change
> which makes pciback a potential candidate to suspect as it
> does change pci configuration space bits.  I need to add some
> tracing and look at the path of execution to answer some of
> your specific questions accurately and I won't be able to do
> that right now but I can give some context to help you based
> on what I have experienced in comparable situation and based
> on that I would say pciback is one place to suspect.  To be a
> bit more specific I would say look into
> pciback_enable_msi/pciback_disable_msi code, add some tracing
> there, observe whether or not that code path is taken when the
> device is disabled/reenabled within guest etc.  To reiterate,
> these are mere suggestions but looks plausible based on prior
> observations.
>>> 
>>> Kamala
>>> 
>>>> -----Original Message-----
>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>> To: Kamala Narasimhan
>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>> re-enabling a PT device in Windows 
>>>> 
>>>> I am not sure i undertand how to test it...
>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>> building the domain? does that happen when i disable the device in
>>>> domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>> device to pciback? and change the xend scripts which check for it?
>>>> 3) Comment out the relevant code - which code??
>>>> 
>>>> I also don't understand, how could it be that the pciback device is
>>>> "messing" with it? isn't it supposed to be in-active when the
>>>> device is being used in PT? 
>>>> 
>>>> Tom
>>>> 
>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>> There is a chance pciback is changing the bit you are referring
>>>> to.  To confirm that, just for testing purpose you might want to
>>>> avoid FLR for that device or simply not build pciback or comment
>>>> out relevant code in that module whichever is easier and see if
>>>> that helps.  If it does, you can then look into fixing the problem
>>>> the right way. 
>>>>> 
>>>>> Kamala
>>>>> 
>>>>>> -----Original Message-----
>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>> Subject: [Xci-devel] Porblem with disabling and then re-enabling
>>>>>> a PT device in Windows 
>>>>>> 
>>>>>> Hi All,
>>>>>> 
>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>> like a different problem - i decided to open a new thread for it)
>>>>>> 
>>>>>> ----
>>>>>> Problem Description:
>>>>>> ----
>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>> it's working ok. Then, i disable the device using Windows device
>>>>>> manager, and the device is now disabled, after that i re-enable
>>>>>> the device, and Windows re-enables the device correctly.
>>>>>> However, the wlan device seems to malfunction (it can't turn on
>>>>>> the WiFi of the computer), and can't connect to wireless
>>>>>> networks. I tried it, both with MSI translation on, and with MSI
>>>>>> translation off - it doesn't matter.  
>>>>>> 
>>>>>> ----
>>>>>> My analysis:
>>>>>> ----
>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>> disable and after the (last) enable, shows that the difference
>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>> and probably waiting for someone to handle it, no? 
>>>>>> 
>>>>>> 2) When i tried to track when did this bit was changed - i added
>>>>>> a code which in every PCI config read, checks if that bit was
>>>>>> changed - and added a print when it changed. The proper lines in
>>>>>> the qemu log looks like this: ...
>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086
>>>>>> len=2 ... 
>>>>>> 
>>>>>> This implies that the bit was changed, about the same time that
>>>>>> Windows tried to start using it (because, i assume that it tried
>>>>>> using it, just after questioning the ACPI for the existence of
>>>>>> the device). No? 
>>>>>> 
>>>>>> 
>>>>>> Can someone help me with this?
>>>>>> 
>>>>>> (BTW - i am using Xen 3.4)
>>>>>> 
>>>>>> Tom
>>>>>> 
>>>>>> _______________________________________________
>>>>>> Xci-devel mailing list
>>>>>> Xci-devel@lists.xensource.com
>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>> 
>>> 
>> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

How do i know if i'm using 'ack_type_new', what does it mean?
Do u have any idea, on how i can check inside domU windows XP (using
WinDBG of-course) if the virtual local APIC/IOAPIC has EOI the
interrupt?

It happens every time... it's 100% reproduceable on that Dell machine.

On Thu, Nov 26, 2009 at 3:40 AM, Jiang, Yunhong <yunhong.jiang@intel.com> wrote:
>
>
> xen-devel-bounces@lists.xensource.com wrote:
>> After digging more into this problem, i found out that the problem is
>> because the interrupt generated on the wlan device, isn't being
>> transfered to the domain, for some reason, after the device was
>> re-enablked in Windows. I saw that, by connecting to the xen console,
>> and then clicking 'i', and i got the following lines:
>> ...
>> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
>> in-flight=1 domain-list=0: 17(----),3: 17(---M),
>> ...
>> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
>> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
>> trigger=level, mask=0 ....
>>
>> You can see, that the interrupt 17, which is in my Windows domU, was
>> generated, but still weren't injected to the CPU (the 'irr' is 1). So,
>> i guess that this is what is causing the problem.
>> Now, the only issue left, is why the hell, the interrupt isn't being
>> injected to the domain?
>
> I assume you are using ack_type_new on your system, am I right?
> Usually it means guest has not EOI the interrupt, so that host has no chance to EOI the physical IOAPIC. Can you check the virtual Local APIC/IOAPIC for the guest to see if we have any finding?
> BTW, does it happen everytime?
>
> --jyh
>
>>
>> Has anyone has any idea about it?
>>
>> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
>> <tom.rotenberg@gmail.com> wrote:
>>> Well, i just performed some tests, and it doesn't look like the
>>> disable_msi/enable_msi functions in pciback are being called at all
>>> (moreover, not in the disable-enable from domU Windows XP), so i
>>> don't think it's related. Also, since when, a config space write
>>> from a guest domU triggers code in the pciback?
>>>
>>> I think that it's not the problem here...
>>> Maybe someone from the XCI can shed some light here, and tell us how
>>> they solve it (or not)? since their code should run on the same Dell
>>> machines, no?
>>>
>>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>> I shouldn't have suggested that you build without pciback;
>> I got carried away trying to make it simple for you :-);
>> Obviously you would need it and I should have stopped with
>> suggesting that you tweak it.
>>>>
>>>> Here is the thought process that led to my suggestion -
>>>>
>>>> Clearly, that bit is getting changed as indicated in your
>> log.  It is unlikely that the guest is triggering that change
>> which makes pciback a potential candidate to suspect as it
>> does change pci configuration space bits.  I need to add some
>> tracing and look at the path of execution to answer some of
>> your specific questions accurately and I won't be able to do
>> that right now but I can give some context to help you based
>> on what I have experienced in comparable situation and based
>> on that I would say pciback is one place to suspect.  To be a
>> bit more specific I would say look into
>> pciback_enable_msi/pciback_disable_msi code, add some tracing
>> there, observe whether or not that code path is taken when the
>> device is disabled/reenabled within guest etc.  To reiterate,
>> these are mere suggestions but looks plausible based on prior
>> observations.
>>>>
>>>> Kamala
>>>>
>>>>> -----Original Message-----
>>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>>> To: Kamala Narasimhan
>>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>>> re-enabling a PT device in Windows
>>>>>
>>>>> I am not sure i undertand how to test it...
>>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>>> building the domain? does that happen when i disable the device in
>>>>> domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>>> device to pciback? and change the xend scripts which check for it?
>>>>> 3) Comment out the relevant code - which code??
>>>>>
>>>>> I also don't understand, how could it be that the pciback device is
>>>>> "messing" with it? isn't it supposed to be in-active when the
>>>>> device is being used in PT?
>>>>>
>>>>> Tom
>>>>>
>>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>> There is a chance pciback is changing the bit you are referring
>>>>> to.  To confirm that, just for testing purpose you might want to
>>>>> avoid FLR for that device or simply not build pciback or comment
>>>>> out relevant code in that module whichever is easier and see if
>>>>> that helps.  If it does, you can then look into fixing the problem
>>>>> the right way.
>>>>>>
>>>>>> Kamala
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>>> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>>> Subject: [Xci-devel] Porblem with disabling and then re-enabling
>>>>>>> a PT device in Windows
>>>>>>>
>>>>>>> Hi All,
>>>>>>>
>>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>>> like a different problem - i decided to open a new thread for it)
>>>>>>>
>>>>>>> ----
>>>>>>> Problem Description:
>>>>>>> ----
>>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>>> it's working ok. Then, i disable the device using Windows device
>>>>>>> manager, and the device is now disabled, after that i re-enable
>>>>>>> the device, and Windows re-enables the device correctly.
>>>>>>> However, the wlan device seems to malfunction (it can't turn on
>>>>>>> the WiFi of the computer), and can't connect to wireless
>>>>>>> networks. I tried it, both with MSI translation on, and with MSI
>>>>>>> translation off - it doesn't matter.
>>>>>>>
>>>>>>> ----
>>>>>>> My analysis:
>>>>>>> ----
>>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>>> disable and after the (last) enable, shows that the difference
>>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>>> and probably waiting for someone to handle it, no?
>>>>>>>
>>>>>>> 2) When i tried to track when did this bit was changed - i added
>>>>>>> a code which in every PCI config read, checks if that bit was
>>>>>>> changed - and added a print when it changed. The proper lines in
>>>>>>> the qemu log looks like this: ...
>>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086
>>>>>>> len=2 ...
>>>>>>>
>>>>>>> This implies that the bit was changed, about the same time that
>>>>>>> Windows tried to start using it (because, i assume that it tried
>>>>>>> using it, just after questioning the ACPI for the existence of
>>>>>>> the device). No?
>>>>>>>
>>>>>>>
>>>>>>> Can someone help me with this?
>>>>>>>
>>>>>>> (BTW - i am using Xen 3.4)
>>>>>>>
>>>>>>> Tom
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Xci-devel mailing list
>>>>>>> Xci-devel@lists.xensource.com
>>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>>>
>>>>
>>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel

Re: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Keir Fraser]

It's printed during Xen boot 'Using {old,new} ACK method'. You can force old
method by adding ioapic_ack=old to the Xen command line.

 -- Keir

On 26/11/2009 05:40, "Tom Rotenberg" <tom.rotenberg@gmail.com> wrote:

> How do i know if i'm using 'ack_type_new', what does it mean?
> Do u have any idea, on how i can check inside domU windows XP (using
> WinDBG of-course) if the virtual local APIC/IOAPIC has EOI the
> interrupt?
> 
> It happens every time... it's 100% reproduceable on that Dell machine.
> 
> On Thu, Nov 26, 2009 at 3:40 AM, Jiang, Yunhong <yunhong.jiang@intel.com>
> wrote:
>> 
>> 
>> xen-devel-bounces@lists.xensource.com wrote:
>>> After digging more into this problem, i found out that the problem is
>>> because the interrupt generated on the wlan device, isn't being
>>> transfered to the domain, for some reason, after the device was
>>> re-enablked in Windows. I saw that, by connecting to the xen console,
>>> and then clicking 'i', and i got the following lines:
>>> ...
>>> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
>>> in-flight=1 domain-list=0: 17(----),3: 17(---M),
>>> ...
>>> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
>>> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
>>> trigger=level, mask=0 ....
>>> 
>>> You can see, that the interrupt 17, which is in my Windows domU, was
>>> generated, but still weren't injected to the CPU (the 'irr' is 1). So,
>>> i guess that this is what is causing the problem.
>>> Now, the only issue left, is why the hell, the interrupt isn't being
>>> injected to the domain?
>> 
>> I assume you are using ack_type_new on your system, am I right?
>> Usually it means guest has not EOI the interrupt, so that host has no chance
>> to EOI the physical IOAPIC. Can you check the virtual Local APIC/IOAPIC for
>> the guest to see if we have any finding?
>> BTW, does it happen everytime?
>> 
>> --jyh
>> 
>>> 
>>> Has anyone has any idea about it?
>>> 
>>> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
>>> <tom.rotenberg@gmail.com> wrote:
>>>> Well, i just performed some tests, and it doesn't look like the
>>>> disable_msi/enable_msi functions in pciback are being called at all
>>>> (moreover, not in the disable-enable from domU Windows XP), so i
>>>> don't think it's related. Also, since when, a config space write
>>>> from a guest domU triggers code in the pciback?
>>>> 
>>>> I think that it's not the problem here...
>>>> Maybe someone from the XCI can shed some light here, and tell us how
>>>> they solve it (or not)? since their code should run on the same Dell
>>>> machines, no?
>>>> 
>>>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>> I shouldn't have suggested that you build without pciback;
>>> I got carried away trying to make it simple for you :-);
>>> Obviously you would need it and I should have stopped with
>>> suggesting that you tweak it.
>>>>> 
>>>>> Here is the thought process that led to my suggestion -
>>>>> 
>>>>> Clearly, that bit is getting changed as indicated in your
>>> log.  It is unlikely that the guest is triggering that change
>>> which makes pciback a potential candidate to suspect as it
>>> does change pci configuration space bits.  I need to add some
>>> tracing and look at the path of execution to answer some of
>>> your specific questions accurately and I won't be able to do
>>> that right now but I can give some context to help you based
>>> on what I have experienced in comparable situation and based
>>> on that I would say pciback is one place to suspect.  To be a
>>> bit more specific I would say look into
>>> pciback_enable_msi/pciback_disable_msi code, add some tracing
>>> there, observe whether or not that code path is taken when the
>>> device is disabled/reenabled within guest etc.  To reiterate,
>>> these are mere suggestions but looks plausible based on prior
>>> observations.
>>>>> 
>>>>> Kamala
>>>>> 
>>>>>> -----Original Message-----
>>>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>>>> To: Kamala Narasimhan
>>>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>>>> re-enabling a PT device in Windows
>>>>>> 
>>>>>> I am not sure i undertand how to test it...
>>>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>>>> building the domain? does that happen when i disable the device in
>>>>>> domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>>>> device to pciback? and change the xend scripts which check for it?
>>>>>> 3) Comment out the relevant code - which code??
>>>>>> 
>>>>>> I also don't understand, how could it be that the pciback device is
>>>>>> "messing" with it? isn't it supposed to be in-active when the
>>>>>> device is being used in PT?
>>>>>> 
>>>>>> Tom
>>>>>> 
>>>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>>> There is a chance pciback is changing the bit you are referring
>>>>>> to.  To confirm that, just for testing purpose you might want to
>>>>>> avoid FLR for that device or simply not build pciback or comment
>>>>>> out relevant code in that module whichever is easier and see if
>>>>>> that helps.  If it does, you can then look into fixing the problem
>>>>>> the right way.
>>>>>>> 
>>>>>>> Kamala
>>>>>>> 
>>>>>>>> -----Original Message-----
>>>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>>>> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>>>> Subject: [Xci-devel] Porblem with disabling and then re-enabling
>>>>>>>> a PT device in Windows
>>>>>>>> 
>>>>>>>> Hi All,
>>>>>>>> 
>>>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>>>> like a different problem - i decided to open a new thread for it)
>>>>>>>> 
>>>>>>>> ----
>>>>>>>> Problem Description:
>>>>>>>> ----
>>>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>>>> it's working ok. Then, i disable the device using Windows device
>>>>>>>> manager, and the device is now disabled, after that i re-enable
>>>>>>>> the device, and Windows re-enables the device correctly.
>>>>>>>> However, the wlan device seems to malfunction (it can't turn on
>>>>>>>> the WiFi of the computer), and can't connect to wireless
>>>>>>>> networks. I tried it, both with MSI translation on, and with MSI
>>>>>>>> translation off - it doesn't matter.
>>>>>>>> 
>>>>>>>> ----
>>>>>>>> My analysis:
>>>>>>>> ----
>>>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>>>> disable and after the (last) enable, shows that the difference
>>>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>>>> and probably waiting for someone to handle it, no?
>>>>>>>> 
>>>>>>>> 2) When i tried to track when did this bit was changed - i added
>>>>>>>> a code which in every PCI config read, checks if that bit was
>>>>>>>> changed - and added a print when it changed. The proper lines in
>>>>>>>> the qemu log looks like this: ...
>>>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086
>>>>>>>> len=2 ...
>>>>>>>> 
>>>>>>>> This implies that the bit was changed, about the same time that
>>>>>>>> Windows tried to start using it (because, i assume that it tried
>>>>>>>> using it, just after questioning the ACPI for the existence of
>>>>>>>> the device). No?
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Can someone help me with this?
>>>>>>>> 
>>>>>>>> (BTW - i am using Xen 3.4)
>>>>>>>> 
>>>>>>>> Tom
>>>>>>>> 
>>>>>>>> _______________________________________________
>>>>>>>> Xci-devel mailing list
>>>>>>>> Xci-devel@lists.xensource.com
>>>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>>>> 
>>>>> 
>>>> 
>>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xensource.com
> http://lists.xensource.com/xen-devel

Re: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

Well... i am using the new ACK method.
I also tried booting with the old ACK method, and got the same
problem, so i guess it's not related to this.

On Thu, Nov 26, 2009 at 9:36 AM, Keir Fraser <keir.fraser@eu.citrix.com> wrote:
> It's printed during Xen boot 'Using {old,new} ACK method'. You can force old
> method by adding ioapic_ack=old to the Xen command line.
>
>  -- Keir
>
> On 26/11/2009 05:40, "Tom Rotenberg" <tom.rotenberg@gmail.com> wrote:
>
>> How do i know if i'm using 'ack_type_new', what does it mean?
>> Do u have any idea, on how i can check inside domU windows XP (using
>> WinDBG of-course) if the virtual local APIC/IOAPIC has EOI the
>> interrupt?
>>
>> It happens every time... it's 100% reproduceable on that Dell machine.
>>
>> On Thu, Nov 26, 2009 at 3:40 AM, Jiang, Yunhong <yunhong.jiang@intel.com>
>> wrote:
>>>
>>>
>>> xen-devel-bounces@lists.xensource.com wrote:
>>>> After digging more into this problem, i found out that the problem is
>>>> because the interrupt generated on the wlan device, isn't being
>>>> transfered to the domain, for some reason, after the device was
>>>> re-enablked in Windows. I saw that, by connecting to the xen console,
>>>> and then clicking 'i', and i got the following lines:
>>>> ...
>>>> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
>>>> in-flight=1 domain-list=0: 17(----),3: 17(---M),
>>>> ...
>>>> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
>>>> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
>>>> trigger=level, mask=0 ....
>>>>
>>>> You can see, that the interrupt 17, which is in my Windows domU, was
>>>> generated, but still weren't injected to the CPU (the 'irr' is 1). So,
>>>> i guess that this is what is causing the problem.
>>>> Now, the only issue left, is why the hell, the interrupt isn't being
>>>> injected to the domain?
>>>
>>> I assume you are using ack_type_new on your system, am I right?
>>> Usually it means guest has not EOI the interrupt, so that host has no chance
>>> to EOI the physical IOAPIC. Can you check the virtual Local APIC/IOAPIC for
>>> the guest to see if we have any finding?
>>> BTW, does it happen everytime?
>>>
>>> --jyh
>>>
>>>>
>>>> Has anyone has any idea about it?
>>>>
>>>> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
>>>> <tom.rotenberg@gmail.com> wrote:
>>>>> Well, i just performed some tests, and it doesn't look like the
>>>>> disable_msi/enable_msi functions in pciback are being called at all
>>>>> (moreover, not in the disable-enable from domU Windows XP), so i
>>>>> don't think it's related. Also, since when, a config space write
>>>>> from a guest domU triggers code in the pciback?
>>>>>
>>>>> I think that it's not the problem here...
>>>>> Maybe someone from the XCI can shed some light here, and tell us how
>>>>> they solve it (or not)? since their code should run on the same Dell
>>>>> machines, no?
>>>>>
>>>>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>> I shouldn't have suggested that you build without pciback;
>>>> I got carried away trying to make it simple for you :-);
>>>> Obviously you would need it and I should have stopped with
>>>> suggesting that you tweak it.
>>>>>>
>>>>>> Here is the thought process that led to my suggestion -
>>>>>>
>>>>>> Clearly, that bit is getting changed as indicated in your
>>>> log.  It is unlikely that the guest is triggering that change
>>>> which makes pciback a potential candidate to suspect as it
>>>> does change pci configuration space bits.  I need to add some
>>>> tracing and look at the path of execution to answer some of
>>>> your specific questions accurately and I won't be able to do
>>>> that right now but I can give some context to help you based
>>>> on what I have experienced in comparable situation and based
>>>> on that I would say pciback is one place to suspect.  To be a
>>>> bit more specific I would say look into
>>>> pciback_enable_msi/pciback_disable_msi code, add some tracing
>>>> there, observe whether or not that code path is taken when the
>>>> device is disabled/reenabled within guest etc.  To reiterate,
>>>> these are mere suggestions but looks plausible based on prior
>>>> observations.
>>>>>>
>>>>>> Kamala
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>>>>> To: Kamala Narasimhan
>>>>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>>>>> re-enabling a PT device in Windows
>>>>>>>
>>>>>>> I am not sure i undertand how to test it...
>>>>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>>>>> building the domain? does that happen when i disable the device in
>>>>>>> domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>>>>> device to pciback? and change the xend scripts which check for it?
>>>>>>> 3) Comment out the relevant code - which code??
>>>>>>>
>>>>>>> I also don't understand, how could it be that the pciback device is
>>>>>>> "messing" with it? isn't it supposed to be in-active when the
>>>>>>> device is being used in PT?
>>>>>>>
>>>>>>> Tom
>>>>>>>
>>>>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>>>> There is a chance pciback is changing the bit you are referring
>>>>>>> to.  To confirm that, just for testing purpose you might want to
>>>>>>> avoid FLR for that device or simply not build pciback or comment
>>>>>>> out relevant code in that module whichever is easier and see if
>>>>>>> that helps.  If it does, you can then look into fixing the problem
>>>>>>> the right way.
>>>>>>>>
>>>>>>>> Kamala
>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>>>>> To: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>>>>> Subject: [Xci-devel] Porblem with disabling and then re-enabling
>>>>>>>>> a PT device in Windows
>>>>>>>>>
>>>>>>>>> Hi All,
>>>>>>>>>
>>>>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>>>>> like a different problem - i decided to open a new thread for it)
>>>>>>>>>
>>>>>>>>> ----
>>>>>>>>> Problem Description:
>>>>>>>>> ----
>>>>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>>>>> it's working ok. Then, i disable the device using Windows device
>>>>>>>>> manager, and the device is now disabled, after that i re-enable
>>>>>>>>> the device, and Windows re-enables the device correctly.
>>>>>>>>> However, the wlan device seems to malfunction (it can't turn on
>>>>>>>>> the WiFi of the computer), and can't connect to wireless
>>>>>>>>> networks. I tried it, both with MSI translation on, and with MSI
>>>>>>>>> translation off - it doesn't matter.
>>>>>>>>>
>>>>>>>>> ----
>>>>>>>>> My analysis:
>>>>>>>>> ----
>>>>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>>>>> disable and after the (last) enable, shows that the difference
>>>>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>>>>> and probably waiting for someone to handle it, no?
>>>>>>>>>
>>>>>>>>> 2) When i tried to track when did this bit was changed - i added
>>>>>>>>> a code which in every PCI config read, checks if that bit was
>>>>>>>>> changed - and added a print when it changed. The proper lines in
>>>>>>>>> the qemu log looks like this: ...
>>>>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000 len=2
>>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000 val=0x00008086
>>>>>>>>> len=2 ...
>>>>>>>>>
>>>>>>>>> This implies that the bit was changed, about the same time that
>>>>>>>>> Windows tried to start using it (because, i assume that it tried
>>>>>>>>> using it, just after questioning the ACPI for the existence of
>>>>>>>>> the device). No?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Can someone help me with this?
>>>>>>>>>
>>>>>>>>> (BTW - i am using Xen 3.4)
>>>>>>>>>
>>>>>>>>> Tom
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> Xci-devel mailing list
>>>>>>>>> Xci-devel@lists.xensource.com
>>>>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>>>>>
>>>>>>
>>>>>
>>>>
>>>> _______________________________________________
>>>> Xen-devel mailing list
>>>> Xen-devel@lists.xensource.com
>>>> http://lists.xensource.com/xen-devel
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>
>
>

RE: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Jiang, Yunhong]

Tom Rotenberg wrote:
> How do i know if i'm using 'ack_type_new', what does it mean?
> Do u have any idea, on how i can check inside domU windows XP (using
> WinDBG of-course) if the virtual local APIC/IOAPIC has EOI the
> interrupt? 

I didn't try windbg to check local/io apic before, although I suppose you can do that since that is simply MMIO access.
Also you can add a hotkey (i.e. the key pressed after the 3 "ctrl+a") to xen hypervisor to dump guest's virtual local apic/ioapic context.

--jyh

> 
> It happens every time... it's 100% reproduceable on that Dell machine.
> 
> On Thu, Nov 26, 2009 at 3:40 AM, Jiang, Yunhong
> <yunhong.jiang@intel.com> wrote:
>> 
>> 
>> xen-devel-bounces@lists.xensource.com wrote:
>>> After digging more into this problem, i found out that the problem
>>> is because the interrupt generated on the wlan device, isn't being
>>> transfered to the domain, for some reason, after the device was
>>> re-enablked in Windows. I saw that, by connecting to the xen
>>> console, and then clicking 'i', and i got the following lines: ...
>>> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
>>> in-flight=1 domain-list=0: 17(----),3: 17(---M),
>>> ...
>>> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
>>> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
>>> trigger=level, mask=0 .... 
>>> 
>>> You can see, that the interrupt 17, which is in my Windows domU, was
>>> generated, but still weren't injected to the CPU (the 'irr' is 1).
>>> So, i guess that this is what is causing the problem.
>>> Now, the only issue left, is why the hell, the interrupt isn't being
>>> injected to the domain?
>> 
>> I assume you are using ack_type_new on your system, am I right?
>> Usually it means guest has not EOI the interrupt, so that
> host has no chance to EOI the physical IOAPIC. Can you check
> the virtual Local APIC/IOAPIC for the guest to see if we have
> any finding?
>> BTW, does it happen everytime?
>> 
>> --jyh
>> 
>>> 
>>> Has anyone has any idea about it?
>>> 
>>> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
>>> <tom.rotenberg@gmail.com> wrote:
>>>> Well, i just performed some tests, and it doesn't look like the
>>>> disable_msi/enable_msi functions in pciback are being called at all
>>>> (moreover, not in the disable-enable from domU Windows XP), so i
>>>> don't think it's related. Also, since when, a config space write
>>>> from a guest domU triggers code in the pciback?
>>>> 
>>>> I think that it's not the problem here...
>>>> Maybe someone from the XCI can shed some light here, and tell us
>>>> how they solve it (or not)? since their code should run on the
>>>> same Dell machines, no? 
>>>> 
>>>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>> I shouldn't have suggested that you build without pciback;
>>> I got carried away trying to make it simple for you :-);
>>> Obviously you would need it and I should have stopped with
>>> suggesting that you tweak it.
>>>>> 
>>>>> Here is the thought process that led to my suggestion -
>>>>> 
>>>>> Clearly, that bit is getting changed as indicated in your
>>> log.  It is unlikely that the guest is triggering that change
>>> which makes pciback a potential candidate to suspect as it
>>> does change pci configuration space bits.  I need to add some
>>> tracing and look at the path of execution to answer some of
>>> your specific questions accurately and I won't be able to do
>>> that right now but I can give some context to help you based
>>> on what I have experienced in comparable situation and based
>>> on that I would say pciback is one place to suspect.  To be a
>>> bit more specific I would say look into
>>> pciback_enable_msi/pciback_disable_msi code, add some tracing
>>> there, observe whether or not that code path is taken when the
>>> device is disabled/reenabled within guest etc.  To reiterate,
>>> these are mere suggestions but looks plausible based on prior
>>> observations.
>>>>> 
>>>>> Kamala
>>>>> 
>>>>>> -----Original Message-----
>>>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>>>> To: Kamala Narasimhan
>>>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>>>> re-enabling a PT device in Windows
>>>>>> 
>>>>>> I am not sure i undertand how to test it...
>>>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>>>> building the domain? does that happen when i disable the device
>>>>>> in domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>>>> device to pciback? and change the xend scripts which check for
>>>>>> it? 3) Comment out the relevant code - which code??
>>>>>> 
>>>>>> I also don't understand, how could it be that the pciback device
>>>>>> is "messing" with it? isn't it supposed to be in-active when the
>>>>>> device is being used in PT? 
>>>>>> 
>>>>>> Tom
>>>>>> 
>>>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>>> There is a chance pciback is changing the bit you are referring
>>>>>> to.  To confirm that, just for testing purpose you might want to
>>>>>> avoid FLR for that device or simply not build pciback or comment
>>>>>> out relevant code in that module whichever is easier and see if
>>>>>> that helps.  If it does, you can then look into fixing the
>>>>>> problem the right way.
>>>>>>> 
>>>>>>> Kamala
>>>>>>> 
>>>>>>>> -----Original Message-----
>>>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>>>> To: xen-devel@lists.xensource.com;
>>>>>>>> xci-devel@lists.xensource.com Subject: [Xci-devel] Porblem
>>>>>>>> with disabling and then re-enabling a PT device in Windows 
>>>>>>>> 
>>>>>>>> Hi All,
>>>>>>>> 
>>>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>>>> like a different problem - i decided to open a new thread for
>>>>>>>> it) 
>>>>>>>> 
>>>>>>>> ----
>>>>>>>> Problem Description:
>>>>>>>> ----
>>>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>>>> it's working ok. Then, i disable the device using Windows
>>>>>>>> device manager, and the device is now disabled, after that i
>>>>>>>> re-enable the device, and Windows re-enables the device
>>>>>>>> correctly. However, the wlan device seems to malfunction (it
>>>>>>>> can't turn on the WiFi of the computer), and can't connect to
>>>>>>>> wireless networks. I tried it, both with MSI translation on,
>>>>>>>> and with MSI translation off - it doesn't matter.
>>>>>>>> 
>>>>>>>> ----
>>>>>>>> My analysis:
>>>>>>>> ----
>>>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>>>> disable and after the (last) enable, shows that the difference
>>>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>>>> and probably waiting for someone to handle it, no?
>>>>>>>> 
>>>>>>>> 2) When i tried to track when did this bit was changed - i
>>>>>>>> added a code which in every PCI config read, checks if that
>>>>>>>> bit was changed - and added a print when it changed. The
>>>>>>>> proper lines in the qemu log looks like this: ...
>>>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000
>>>>>>>> len=2 ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000
>>>>>>>> val=0x00008086 len=2 ... 
>>>>>>>> 
>>>>>>>> This implies that the bit was changed, about the same time that
>>>>>>>> Windows tried to start using it (because, i assume that it
>>>>>>>> tried using it, just after questioning the ACPI for the
>>>>>>>> existence of the device). No? 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> Can someone help me with this?
>>>>>>>> 
>>>>>>>> (BTW - i am using Xen 3.4)
>>>>>>>> 
>>>>>>>> Tom
>>>>>>>> 
>>>>>>>> _______________________________________________
>>>>>>>> Xci-devel mailing list
>>>>>>>> Xci-devel@lists.xensource.com
>>>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>>>> 
>>>>> 
>>>> 
>>> 
>>> _______________________________________________
>>> Xen-devel mailing list
>>> Xen-devel@lists.xensource.com
>>> http://lists.xensource.com/xen-devel

Re: Re: [Xci-devel] Porblem with disabling and then re-enabling a PT device in Windows

[Tom Rotenberg]

Well, as an updtae, i found the followings:
after i do a disable, and then re-enable, the interrupt is "kind-of"
stuck for ~1:30 minutes, and after that, the interrupt is somehow
released, and everything works ok.
I tested it a few times, and in each time the interrupt was released
about ~1:30 minutes later.

Does that imples anything? or is that probably just a recover of the
Windows driver?

On Thu, Nov 26, 2009 at 9:55 AM, Jiang, Yunhong <yunhong.jiang@intel.com> wrote:
>
> Tom Rotenberg wrote:
>> How do i know if i'm using 'ack_type_new', what does it mean?
>> Do u have any idea, on how i can check inside domU windows XP (using
>> WinDBG of-course) if the virtual local APIC/IOAPIC has EOI the
>> interrupt?
>
> I didn't try windbg to check local/io apic before, although I suppose you can do that since that is simply MMIO access.
> Also you can add a hotkey (i.e. the key pressed after the 3 "ctrl+a") to xen hypervisor to dump guest's virtual local apic/ioapic context.
>
> --jyh
>
>>
>> It happens every time... it's 100% reproduceable on that Dell machine.
>>
>> On Thu, Nov 26, 2009 at 3:40 AM, Jiang, Yunhong
>> <yunhong.jiang@intel.com> wrote:
>>>
>>>
>>> xen-devel-bounces@lists.xensource.com wrote:
>>>> After digging more into this problem, i found out that the problem
>>>> is because the interrupt generated on the wlan device, isn't being
>>>> transfered to the domain, for some reason, after the device was
>>>> re-enablked in Windows. I saw that, by connecting to the xen
>>>> console, and then clicking 'i', and i got the following lines: ...
>>>> (XEN)    Vec192 IRQ 17: type=IO-APIC-level   status=00000010
>>>> in-flight=1 domain-list=0: 17(----),3: 17(---M),
>>>> ...
>>>> (XEN)       Apic 0x00, Pin 17: vector=192, delivery_mode=1,
>>>> dest_mode=logical, delivery_status=1, polarity=1, irr=1,
>>>> trigger=level, mask=0 ....
>>>>
>>>> You can see, that the interrupt 17, which is in my Windows domU, was
>>>> generated, but still weren't injected to the CPU (the 'irr' is 1).
>>>> So, i guess that this is what is causing the problem.
>>>> Now, the only issue left, is why the hell, the interrupt isn't being
>>>> injected to the domain?
>>>
>>> I assume you are using ack_type_new on your system, am I right?
>>> Usually it means guest has not EOI the interrupt, so that
>> host has no chance to EOI the physical IOAPIC. Can you check
>> the virtual Local APIC/IOAPIC for the guest to see if we have
>> any finding?
>>> BTW, does it happen everytime?
>>>
>>> --jyh
>>>
>>>>
>>>> Has anyone has any idea about it?
>>>>
>>>> On Wed, Nov 25, 2009 at 6:31 PM, Tom Rotenberg
>>>> <tom.rotenberg@gmail.com> wrote:
>>>>> Well, i just performed some tests, and it doesn't look like the
>>>>> disable_msi/enable_msi functions in pciback are being called at all
>>>>> (moreover, not in the disable-enable from domU Windows XP), so i
>>>>> don't think it's related. Also, since when, a config space write
>>>>> from a guest domU triggers code in the pciback?
>>>>>
>>>>> I think that it's not the problem here...
>>>>> Maybe someone from the XCI can shed some light here, and tell us
>>>>> how they solve it (or not)? since their code should run on the
>>>>> same Dell machines, no?
>>>>>
>>>>> On Wed, Nov 25, 2009 at 5:13 PM, Kamala Narasimhan
>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>> I shouldn't have suggested that you build without pciback;
>>>> I got carried away trying to make it simple for you :-);
>>>> Obviously you would need it and I should have stopped with
>>>> suggesting that you tweak it.
>>>>>>
>>>>>> Here is the thought process that led to my suggestion -
>>>>>>
>>>>>> Clearly, that bit is getting changed as indicated in your
>>>> log.  It is unlikely that the guest is triggering that change
>>>> which makes pciback a potential candidate to suspect as it
>>>> does change pci configuration space bits.  I need to add some
>>>> tracing and look at the path of execution to answer some of
>>>> your specific questions accurately and I won't be able to do
>>>> that right now but I can give some context to help you based
>>>> on what I have experienced in comparable situation and based
>>>> on that I would say pciback is one place to suspect.  To be a
>>>> bit more specific I would say look into
>>>> pciback_enable_msi/pciback_disable_msi code, add some tracing
>>>> there, observe whether or not that code path is taken when the
>>>> device is disabled/reenabled within guest etc.  To reiterate,
>>>> these are mere suggestions but looks plausible based on prior
>>>> observations.
>>>>>>
>>>>>> Kamala
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Tom Rotenberg [mailto:tom.rotenberg@gmail.com]
>>>>>>> Sent: Wednesday, November 25, 2009 9:22 AM
>>>>>>> To: Kamala Narasimhan
>>>>>>> Cc: xen-devel@lists.xensource.com; xci-devel@lists.xensource.com
>>>>>>> Subject: Re: [Xci-devel] Porblem with disabling and then
>>>>>>> re-enabling a PT device in Windows
>>>>>>>
>>>>>>> I am not sure i undertand how to test it...
>>>>>>> 1) Avoid doing FLR for the device - isn';t that done only when
>>>>>>> building the domain? does that happen when i disable the device
>>>>>>> in domU? 2) Don't build pciback - and then, i won't bind the wlan
>>>>>>> device to pciback? and change the xend scripts which check for
>>>>>>> it? 3) Comment out the relevant code - which code??
>>>>>>>
>>>>>>> I also don't understand, how could it be that the pciback device
>>>>>>> is "messing" with it? isn't it supposed to be in-active when the
>>>>>>> device is being used in PT?
>>>>>>>
>>>>>>> Tom
>>>>>>>
>>>>>>> On Wed, Nov 25, 2009 at 4:12 PM, Kamala Narasimhan
>>>>>>> <Kamala.Narasimhan@citrix.com> wrote:
>>>>>>>> There is a chance pciback is changing the bit you are referring
>>>>>>> to.  To confirm that, just for testing purpose you might want to
>>>>>>> avoid FLR for that device or simply not build pciback or comment
>>>>>>> out relevant code in that module whichever is easier and see if
>>>>>>> that helps.  If it does, you can then look into fixing the
>>>>>>> problem the right way.
>>>>>>>>
>>>>>>>> Kamala
>>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: xci-devel-bounces@lists.xensource.com [mailto:xci-devel-
>>>>>>>>> bounces@lists.xensource.com] On Behalf Of Tom Rotenberg
>>>>>>>>> Sent: Wednesday, November 25, 2009 8:09 AM
>>>>>>>>> To: xen-devel@lists.xensource.com;
>>>>>>>>> xci-devel@lists.xensource.com Subject: [Xci-devel] Porblem
>>>>>>>>> with disabling and then re-enabling a PT device in Windows
>>>>>>>>>
>>>>>>>>> Hi All,
>>>>>>>>>
>>>>>>>>> (This is a continuation to my previous mail, but since it looks
>>>>>>>>> like a different problem - i decided to open a new thread for
>>>>>>>>> it)
>>>>>>>>>
>>>>>>>>> ----
>>>>>>>>> Problem Description:
>>>>>>>>> ----
>>>>>>>>> I am doing pass-through of an Intel wireless LAN device to a
>>>>>>>>> Windows XP domU (my machine is Dell e6400), and it looks like
>>>>>>>>> it's working ok. Then, i disable the device using Windows
>>>>>>>>> device manager, and the device is now disabled, after that i
>>>>>>>>> re-enable the device, and Windows re-enables the device
>>>>>>>>> correctly. However, the wlan device seems to malfunction (it
>>>>>>>>> can't turn on the WiFi of the computer), and can't connect to
>>>>>>>>> wireless networks. I tried it, both with MSI translation on,
>>>>>>>>> and with MSI translation off - it doesn't matter.
>>>>>>>>>
>>>>>>>>> ----
>>>>>>>>> My analysis:
>>>>>>>>> ----
>>>>>>>>> 1) Well, taking a look at the real PCI config space, before
>>>>>>>>> disable and after the (last) enable, shows that the difference
>>>>>>>>> is at the Intx bit (read-only bit 3 at status register (offset
>>>>>>>>> 0x6) at the PCI config space). Before disable, that bit was 0,
>>>>>>>>> and after the last enable that bit was 1. This, according to my
>>>>>>>>> understanding, means that the device is asserting it's IntX ,
>>>>>>>>> and probably waiting for someone to handle it, no?
>>>>>>>>>
>>>>>>>>> 2) When i tried to track when did this bit was changed - i
>>>>>>>>> added a code which in every PCI config read, checks if that
>>>>>>>>> bit was changed - and added a print when it changed. The
>>>>>>>>> proper lines in the qemu log looks like this: ...
>>>>>>>>> pt_pci_read_config: [00:01.0]: address=00f0 val=0x00000000
>>>>>>>>> len=2 ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>>> ACPI PCI hotplug: read addr=0x10c6, val=0x0f.
>>>>>>>>> pt_pci_read_config: TEST CODE: STATUS CHNAGED! OLD: 0x10, NEW:
>>>>>>>>> 0x18 pt_pci_read_config: [00:01.0]: address=0000
>>>>>>>>> val=0x00008086 len=2 ...
>>>>>>>>>
>>>>>>>>> This implies that the bit was changed, about the same time that
>>>>>>>>> Windows tried to start using it (because, i assume that it
>>>>>>>>> tried using it, just after questioning the ACPI for the
>>>>>>>>> existence of the device). No?
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Can someone help me with this?
>>>>>>>>>
>>>>>>>>> (BTW - i am using Xen 3.4)
>>>>>>>>>
>>>>>>>>> Tom
>>>>>>>>>
>>>>>>>>> _______________________________________________
>>>>>>>>> Xci-devel mailing list
>>>>>>>>> Xci-devel@lists.xensource.com
>>>>>>>>> http://lists.xensource.com/mailman/listinfo/xci-devel
>>>>>>>>
>>>>>>
>>>>>
>>>>
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