Re: genirq: Flags mismatch irq 17. 00000000 (vfio-intx(0000:07:04.0)) vs. 00000000 (vfio-intx(0000:01:00.1))

[Dana Goyette <DanaGoyette@gmail.com>]

On 01/10/2014 09:33 AM, Alex Williamson wrote:
> On Fri, 2014-01-10 at 08:23 -0800, Dana Goyette wrote:
>> I'm using the SuperMicro X10SAT, kernel 3.13-rc5, with ACS override on
>> Intel root ports.
>>
>> I'm trying to pass several devices to the same guest:
>>
>> 01:00.0 -- [1002:68be] Radeon HD 5750
>> 01:00.1 -- [1002:aa58] HDMI Audio (not really needed)
>> 07:04.0 -- [13f6:8788] Xonar D1/DX sound card, behind PEX8112
>> 09:00.0 -- [1912:0014] Renesas uPD720201 (USB 3.0)
>>
>> When trying to start qemu with various combinations of those devices:
>> vfio: Error: Failed to setup INTx fd: Device or resource busy
>>
>> Sound card conflicts with HDMI audio:
>> genirq: Flags mismatch irq 17.
>> 00000000 (vfio-intx(0000:07:04.0)) vs.
>> 00000000 (vfio-intx(0000:01:00.1))
>>
>> USB controller conflicts with video card:
>> genirq: Flags mismatch irq 16.
>> 00000000 (vfio-intx(0000:09:00.0)) vs.
>> 00000000 (vfio-intx(0000:01:00.0))
>>
>> On the ArchLinux forums, I was told that this means each device wants
>> the interrupt line to itself.
>>
>> Oddly, the host locks up if I launch Xorg with 'radeon' and
>> 'snd-virtuoso' both loaded.  (Primary video is the Intel graphics.)
>>
>> These devices all work fine together using pci-assign, but pci-assign
>> requires ejecting the Radeon before VM shutdown.
>>
>> VFIO allows me to start the VM if I forward only the sound card and the
>> video card, but I really need the USB controller, as well.
>>
>> What can I do to forward those three devices via VFIO?
>
> Change slots until the interrupts don't conflict, maybe there's an
> IO-APIC option you can enable in the BIOS, or get devices that properly
> support PCI2.3 INTx disable.  pci-assign tries to work around this by
> using MSI to emulate INTx, but I'm not convinced that this doesn't
> create more problems than it solves or I'd try to do the same with vfio.
> The Xorg problem might also suggest there's an existing interrupt
> routing problem on the system.  It is surprising that you have so many
> devices that doesn't support INTx disable, can you try running this
> script on them:
>
> #!/bin/sh
> # Usage $0 <PCI device>, ex: 9:00.0
>
> INTX=$(( 0x400 ))
> ORIG=$(( 0x$(setpci -s $1 4.w) ))
>
> if [ $(( $INTX & $ORIG )) -ne 0 ]; then
> 	echo "INTx disable supported and enabled on $1"
> 	exit 0
> fi
>
> NEW=$(printf %04x $(( $INTX | $ORIG )))
> setpci -s $1 4.w=$NEW
> NEW=$(( 0x$(setpci -s $1 4.w) ))
>
> if [ $(( $INTX & $NEW )) -ne 0 ]; then
> 	echo "INTx disable support available on $1"
> else
> 	echo "INTx disable support NOT available on $1"
> fi
>
> NEW=$(printf %04x $ORIG)
> setpci -s $1 4.w=$NEW
>
>
> --
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After cold boot, without any attempts to run VM:

Video card:
INTx disable support available on 01:00.0

HDMI Audio:
INTx disable supported and enabled on 01:00.1

USB:
INTx disable supported and enabled on 09:00.0

PEX8112 (sound card sits behind this):
INTx disable support available on 06:00.0)

Sound card:
INTx disable support NOT available on 07:04.0

If the sound card is the only one lacking this feature, then it seems 
odd that the USB controller is the one I have to remove for the VM to boot.

The lspci -nnvv listing for my current sound card is quite sparse:

07:04.0 Multimedia audio controller [0401]: C-Media Electronics Inc 
CMI8788 [Oxygen HD Audio] [13f6:8788]
	Subsystem: ASUSTeK Computer Inc. Virtuoso 100 (Xonar D1) [1043:834f]
	Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- 
Stepping- SERR+ FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- 
<TAbort- <MAbort- >SERR- <PERR- INTx-
	Interrupt: pin A routed to IRQ 10
	Region 0: I/O ports at c000 [disabled] [size=256]
	Capabilities: [c0] Power Management version 2
		Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-

I'm willing to purchase a different sound card if that will fix the 
problem.  Does lspci (-v or -vv) tell you if INTx Disable is available?