Re: AMD KVM Pci Passthrough reports device busy

[Andreas Hartmann <andihartmann@01019freenet.de>]

Andreas Hartmann wrote:
> On Wed, 6 Jun 2012 10:12:27 +0200
> Andreas Hartmann <andihartmann@01019freenet.de> wrote:
> 
>> On Tue, 05 Jun 2012 18:55:42 +0200
>> Andreas Hartmann <andihartmann@01019freenet.de> wrote:
>>
>>> Alex Williamson wrote:
>>> [...]
>>>> Yep, I think the previous suggestion about reloading vfio_iommu_type1
>>>> with allow_unsafe_interrupts=1 will solve it.
>>>
>>> Yes! Works now. Success!!!!!
>>>
>>> Works means: Device is seen in VM. I couldn't test it up to now, because
>>> I don't have any driver in the VM for this device.
>>
>> Meanwhile, I enabled the drivers in the VM for the device I passed
>> through. Unfortunately, it doesn't work :-(. I'm getting this entry in
>> messages at the moment, the module rt2800pci is used by hostapd:
>>
>> Jun  6 09:25:02 host kernel: [  201.895812] irq 21: nobody cared (try booting with the "irqpoll" option)
>> Jun  6 09:25:02 host kernel: [  201.895819] Pid: 0, comm: swapper/1 Not tainted 3.4.0-next-20120529-16.1-desktop #6
>> Jun  6 09:25:02 host kernel: [  201.895822] Call Trace:
>> Jun  6 09:25:02 host kernel: [  201.895836]  <IRQ>  [<ffffffff810d37a8>] __report_bad_irq+0x38/0xe0
>> Jun  6 09:25:02 host kernel: [  201.895842]  [<ffffffff810d3a6d>] note_interrupt+0x16d/0x220
>> Jun  6 09:25:02 host kernel: [  201.895849]  [<ffffffff810d12d6>] handle_irq_event_percpu+0xc6/0x270
>> Jun  6 09:25:02 host kernel: [  201.895855]  [<ffffffff810d14c9>] handle_irq_event+0x49/0x70
>> Jun  6 09:25:02 host kernel: [  201.895860]  [<ffffffff810d45d2>] handle_fasteoi_irq+0x82/0x130
>> Jun  6 09:25:02 host kernel: [  201.895865]  [<ffffffff81004460>] handle_irq+0x20/0x30
>> Jun  6 09:25:02 host kernel: [  201.895869]  [<ffffffff81004098>] do_IRQ+0x58/0xe0
>> Jun  6 09:25:02 host kernel: [  201.895876]  [<ffffffff815f112a>] common_interrupt+0x6a/0x6a
>> Jun  6 09:25:02 host kernel: [  201.895907]  <EOI>  [<ffffffffa0029077>] ? arch_local_irq_enable+0x8/0xd [processor]
>> Jun  6 09:25:02 host kernel: [  201.895915]  [<ffffffff8107a37a>] ? sched_clock_idle_wakeup_event+0x1a/0x20
>> Jun  6 09:25:02 host kernel: [  201.895929]  [<ffffffffa002a046>] acpi_idle_enter_simple+0xd0/0x111 [processor]
>> Jun  6 09:25:02 host kernel: [  201.895939]  [<ffffffff814915f9>] cpuidle_enter+0x19/0x20
>> Jun  6 09:25:02 host kernel: [  201.895943]  [<ffffffff81491d81>] cpuidle_idle_call+0xc1/0x1e0
>> Jun  6 09:25:02 host kernel: [  201.895949]  [<ffffffff8100bd45>] cpu_idle+0x85/0xd0
>> Jun  6 09:25:02 host kernel: [  201.895955]  [<ffffffff815e63d5>] start_secondary+0x8a/0x8c
>> Jun  6 09:25:02 host kernel: [  201.895958] handlers:
>> Jun  6 09:25:02 host kernel: [  201.895967] [<ffffffffa0488230>] vfio_intx_handler [vfio_pci] threaded [<ffffffffa04884e0>] vfio_intx_thread [vfio_pci]
>> Jun  6 09:25:02 host kernel: [  201.895969] Disabling IRQ #21
>>
>> I tried with irqpoll, but this didn't help. BTW: IRQ 21 isn't a shared
>> interrupt! Did I miss an option during kernel configuration?
> 
> No device at all here listens for IRQ 21. The WLAN-device is at IRQ 5
> (no shared IRQ)!

To be more precise:

after the bind procedure, the device is at IRQ 5. After starting of
/usr/local/bin/qemu-system-x86_64, it's at 21.

> 
> [...]
> 
>> lspci -vs7
>> 06:07.0 Network controller: Ralink corp. RT2800 802.11n PCI
>>         Subsystem: Linksys Device 0067
>>         Flags: bus master, slow devsel, latency 32, IRQ 5
>>         Memory at fd8e0000 (32-bit, non-prefetchable) [size=64K]
>>         Capabilities: [40] Power Management version 3
>>         Kernel driver in use: vfio-pci
> 
> What's going on here? Where does interrupt 21 come from? It should be 5!

-> this is before starting of /usr/local/bin/qemu-system-x86_64.

That's after starting of the VM:

06:07.0 Network controller: Ralink corp. RT2800 802.11n PCI
        Subsystem: Linksys Device 0067
        Flags: bus master, slow devsel, latency 32, IRQ 21
        Memory at fd8e0000 (32-bit, non-prefetchable) [size=64K]
        Capabilities: [40] Power Management version 3
        Kernel driver in use: vfio-pci




Thanks,
kind regards,
Andreas