Binding ISA Irq seems to malfunction in Xen 3.4

Binding ISA Irq seems to malfunction in Xen 3.4

[Tom Rotenberg]

Hi,

I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
order to bind the real machine irq of the keyboard & mouse (interrupts
12 & 1), to a specific domain, so he will be ale to use the PS2
keyboard & mouse in pass-through.
Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
i keep getting an error code, and the function fails to bind the
interrupt. I also, performed a search, and found that no-one is using
this function, so i'm afarid that this function doesn't work at all.

I also want to know, how can i debug this problem? Could it be related
to the fact that the interrupt i'm trying to bind, is already
"connected" do dom0 (as he uses the keyboard & mouse)?
Can someone please help me with this?

Tom

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Jan Beulich]

>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>order to bind the real machine irq of the keyboard & mouse (interrupts
>12 & 1), to a specific domain, so he will be ale to use the PS2
>keyboard & mouse in pass-through.
>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>i keep getting an error code, and the function fails to bind the
>interrupt. I also, performed a search, and found that no-one is using
>this function, so i'm afarid that this function doesn't work at all.
>
>I also want to know, how can i debug this problem? Could it be related
>to the fact that the interrupt i'm trying to bind, is already
>"connected" do dom0 (as he uses the keyboard & mouse)?
>Can someone please help me with this?

You obviously first need to make sure Dom0 doesn't use the IRQ - for
one ISA IRQs are not shareable, but more importantly you really don't
intend to have two domains drive the same hardware, do you? And
you may have some difficulty doing so since (without patching the code)
you can't even configure the Dom0 kernel to not have an 8042 driver
on x86 (unless you select EMBEDDED), i.e. it will always attach to the
device if there is one.

Jan

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Tom Rotenberg]

I understand...

and can i compile the i8042 module, as a loadable kernel module
(instead of staticly in the kernel), and then simply 'rmmod' the i8042
module, and it will work?

On Fri, Nov 13, 2009 at 11:22 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>>order to bind the real machine irq of the keyboard & mouse (interrupts
>>12 & 1), to a specific domain, so he will be ale to use the PS2
>>keyboard & mouse in pass-through.
>>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>>i keep getting an error code, and the function fails to bind the
>>interrupt. I also, performed a search, and found that no-one is using
>>this function, so i'm afarid that this function doesn't work at all.
>>
>>I also want to know, how can i debug this problem? Could it be related
>>to the fact that the interrupt i'm trying to bind, is already
>>"connected" do dom0 (as he uses the keyboard & mouse)?
>>Can someone please help me with this?
>
> You obviously first need to make sure Dom0 doesn't use the IRQ - for
> one ISA IRQs are not shareable, but more importantly you really don't
> intend to have two domains drive the same hardware, do you? And
> you may have some difficulty doing so since (without patching the code)
> you can't even configure the Dom0 kernel to not have an 8042 driver
> on x86 (unless you select EMBEDDED), i.e. it will always attach to the
> device if there is one.
>
> Jan
>
>

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Jan Beulich]

>>> Tom Rotenberg <tom.rotenberg@gmail.com> 13.11.09 11:19 >>>
>and can i compile the i8042 module, as a loadable kernel module
>(instead of staticly in the kernel), and then simply 'rmmod' the i8042
>module, and it will work?

No, you're not being presented with the config option prompt to select
it to be a module (otherwise you would also be able to turn it off).

Jan

On Fri, Nov 13, 2009 at 11:22 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>>order to bind the real machine irq of the keyboard & mouse (interrupts
>>12 & 1), to a specific domain, so he will be ale to use the PS2
>>keyboard & mouse in pass-through.
>>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>>i keep getting an error code, and the function fails to bind the
>>interrupt. I also, performed a search, and found that no-one is using
>>this function, so i'm afarid that this function doesn't work at all.
>>
>>I also want to know, how can i debug this problem? Could it be related
>>to the fact that the interrupt i'm trying to bind, is already
>>"connected" do dom0 (as he uses the keyboard & mouse)?
>>Can someone please help me with this?
>
> You obviously first need to make sure Dom0 doesn't use the IRQ - for
> one ISA IRQs are not shareable, but more importantly you really don't
> intend to have two domains drive the same hardware, do you? And
> you may have some difficulty doing so since (without patching the code)
> you can't even configure the Dom0 kernel to not have an 8042 driver
> on x86 (unless you select EMBEDDED), i.e. it will always attach to the
> device if there is one.
>
> Jan
>
>

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Tom Rotenberg]

So, the only way to do this, is to compile the dom0 kernel, with the
'EMBEDDED' (CONFIG_EMBEDDED?) option, and then to try to bind those
ISA interrupts?

Do u have any idea, how the code in XCI implements this?

On Fri, Nov 13, 2009 at 12:23 PM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 13.11.09 11:19 >>>
>>and can i compile the i8042 module, as a loadable kernel module
>>(instead of staticly in the kernel), and then simply 'rmmod' the i8042
>>module, and it will work?
>
> No, you're not being presented with the config option prompt to select
> it to be a module (otherwise you would also be able to turn it off).
>
> Jan
>
> On Fri, Nov 13, 2009 at 11:22 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>>>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>>>order to bind the real machine irq of the keyboard & mouse (interrupts
>>>12 & 1), to a specific domain, so he will be ale to use the PS2
>>>keyboard & mouse in pass-through.
>>>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>>>i keep getting an error code, and the function fails to bind the
>>>interrupt. I also, performed a search, and found that no-one is using
>>>this function, so i'm afarid that this function doesn't work at all.
>>>
>>>I also want to know, how can i debug this problem? Could it be related
>>>to the fact that the interrupt i'm trying to bind, is already
>>>"connected" do dom0 (as he uses the keyboard & mouse)?
>>>Can someone please help me with this?
>>
>> You obviously first need to make sure Dom0 doesn't use the IRQ - for
>> one ISA IRQs are not shareable, but more importantly you really don't
>> intend to have two domains drive the same hardware, do you? And
>> you may have some difficulty doing so since (without patching the code)
>> you can't even configure the Dom0 kernel to not have an 8042 driver
>> on x86 (unless you select EMBEDDED), i.e. it will always attach to the
>> device if there is one.
>>
>> Jan
>>
>>
>
>

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Jan Beulich]

>>> Tom Rotenberg <tom.rotenberg@gmail.com> 13.11.09 11:27 >>>
>So, the only way to do this, is to compile the dom0 kernel, with the
>'EMBEDDED' (CONFIG_EMBEDDED?) option, and then to try to bind those
>ISA interrupts?

I think so.

>Do u have any idea, how the code in XCI implements this?

No.

Jan

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Tom Rotenberg]

Thanks! i will try it.

On Fri, Nov 13, 2009 at 12:38 PM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 13.11.09 11:27 >>>
>>So, the only way to do this, is to compile the dom0 kernel, with the
>>'EMBEDDED' (CONFIG_EMBEDDED?) option, and then to try to bind those
>>ISA interrupts?
>
> I think so.
>
>>Do u have any idea, how the code in XCI implements this?
>
> No.
>
> Jan
>
>

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Tom Rotenberg]

Hi Jan/All,

Just tried the following:
i booted dom0, with i8042.nokbd and i8042.no_aux options, which caused
the i8042 driver not to use the ps2 keyboard & mouse.
I saw that these indeed the case, by doing:
#  cat /proc/interrupts
           CPU0       CPU1
  3:          2          0  Phys-irq-level
  7:          0          0  Phys-irq-level     parport0
  8:          0          0  Phys-irq-level     rtc0
  9:        293          0  Phys-irq-level     acpi
 17:          2          0  Phys-irq-level     ohci1394
 18:          0          0  Phys-irq-level     sdhci:slot0
...

and i saw that the i8042 no longer uses the keyboard & mouse interrupts.

However, i still can't bing the ISA interrupt to the VM, using the
'xc_domain_bind_pt_isa_irq()' function.

Any idea on why this is happening? has anyone tested this function on
Xen 3.4 and newer xen versions?
Can this be some kind of a VT-d issue?

Tom


On Fri, Nov 13, 2009 at 11:22 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>>order to bind the real machine irq of the keyboard & mouse (interrupts
>>12 & 1), to a specific domain, so he will be ale to use the PS2
>>keyboard & mouse in pass-through.
>>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>>i keep getting an error code, and the function fails to bind the
>>interrupt. I also, performed a search, and found that no-one is using
>>this function, so i'm afarid that this function doesn't work at all.
>>
>>I also want to know, how can i debug this problem? Could it be related
>>to the fact that the interrupt i'm trying to bind, is already
>>"connected" do dom0 (as he uses the keyboard & mouse)?
>>Can someone please help me with this?
>
> You obviously first need to make sure Dom0 doesn't use the IRQ - for
> one ISA IRQs are not shareable, but more importantly you really don't
> intend to have two domains drive the same hardware, do you? And
> you may have some difficulty doing so since (without patching the code)
> you can't even configure the Dom0 kernel to not have an 8042 driver
> on x86 (unless you select EMBEDDED), i.e. it will always attach to the
> device if there is one.
>
> Jan
>
>

Re: Binding ISA Irq seems to malfunction in Xen 3.4

[Jan Beulich]

Sorry, no - unless you got meaningful log entries somewhere, I'm afraid
you won't get around debugging this. Jan

>>> Tom Rotenberg <tom.rotenberg@gmail.com> 17.11.09 19:19 >>>
Hi Jan/All,

Just tried the following:
i booted dom0, with i8042.nokbd and i8042.no_aux options, which caused
the i8042 driver not to use the ps2 keyboard & mouse.
I saw that these indeed the case, by doing:
#  cat /proc/interrupts
           CPU0       CPU1
  3:          2          0  Phys-irq-level
  7:          0          0  Phys-irq-level     parport0
  8:          0          0  Phys-irq-level     rtc0
  9:        293          0  Phys-irq-level     acpi
 17:          2          0  Phys-irq-level     ohci1394
 18:          0          0  Phys-irq-level     sdhci:slot0
...

and i saw that the i8042 no longer uses the keyboard & mouse interrupts.

However, i still can't bing the ISA interrupt to the VM, using the
'xc_domain_bind_pt_isa_irq()' function.

Any idea on why this is happening? has anyone tested this function on
Xen 3.4 and newer xen versions?
Can this be some kind of a VT-d issue?

Tom


On Fri, Nov 13, 2009 at 11:22 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> Tom Rotenberg <tom.rotenberg@gmail.com> 12.11.09 18:51 >>>
>>I'm trying to use the function: 'xc_domain_bind_pt_isa_irq()', in
>>order to bind the real machine irq of the keyboard & mouse (interrupts
>>12 & 1), to a specific domain, so he will be ale to use the PS2
>>keyboard & mouse in pass-through.
>>Howeverm when i perform the call to the 'xc_domain_bind_pt_isa_irq()',
>>i keep getting an error code, and the function fails to bind the
>>interrupt. I also, performed a search, and found that no-one is using
>>this function, so i'm afarid that this function doesn't work at all.
>>
>>I also want to know, how can i debug this problem? Could it be related
>>to the fact that the interrupt i'm trying to bind, is already
>>"connected" do dom0 (as he uses the keyboard & mouse)?
>>Can someone please help me with this?
>
> You obviously first need to make sure Dom0 doesn't use the IRQ - for
> one ISA IRQs are not shareable, but more importantly you really don't
> intend to have two domains drive the same hardware, do you? And
> you may have some difficulty doing so since (without patching the code)
> you can't even configure the Dom0 kernel to not have an 8042 driver
> on x86 (unless you select EMBEDDED), i.e. it will always attach to the
> device if there is one.
>
> Jan
>
>