Re: [Xen-devel] Re: HVM DomU, msi_translate=0, MSI/MSI-X PCI passthrough fails.

[Mark Adams <mark@xxxxxxxxxxxxxxxxxx>]

On Wed, Dec 08, 2010 at 02:37:15PM +0100, Sander Eikelenboom wrote:
> Hello Mark,

Hi

> 
> Just a recap:
>      you pass through:
>      - 3 physical nics/IGB
>      - 1 ISDN pci ISDN box

The redfone box runs on 1 of the nics - its not seperate. It converts
ISDN to TDMoE see here.. http://www.red-fone.com/

>      - all using msi/msi-x interrupts ?

I tried using msi/msi-x interrupts, but it caused the raid card to drop
off (after some use) and provided seemingly even worse performance than
pegging everything back to legacy.

> 
> Have you tried using a PV domU instead of a HVM domU ?

I initially tried PV but had issues with the igb NIC's. There was
another thread somewhere about my issues with that.


> Have you tried passing through only the ISDN box, and let the network run 
> with the xen backend/frontend to rule out the IGB/network stuff ?
> 
> 
> --
> Sander
> 
> 
> 
> Wednesday, December 8, 2010, 1:58:55 PM, you wrote:
> 
> > Hi - Apologies to top post this, but after alot of testing, I believe
> > there must be an issue with IRQ's going missing between domU and dom0.
> > Unfortunately I have no data to prove this!
> 
> > With msitranslate=0 as detailed below, and pci=nomsi in the guest kernel
> > grub config, all 3 NIC's appear OK in the domU however I still had
> > issues with the red-fone ISDN box. The interrupts were showing correctly
> > (2000/s) in the domU but communication to the device via the NIC was
> > still being interrupted (as shown in the asterisk console)Note that to
> > get the igb driver to allow this many interrupts, the
> > InterruptThrottleRate was set to 0. The same config (red-fone box,
> > asterisk etc) works fine with a physical server.
> 
> > There is also the additional issue that I could not get the passthrough
> > NIC's to show correctly when I also had a bridge setup.
> 
> > Throughout my testing however, I could not get the machine to crash.
> 
> > Not sure where to go with this one. For now we are keeping our VoIP
> > servers physical when ISDN connections are required.
> 
> > Regards,
> > Mark
> 
> > On Mon, Nov 29, 2010 at 11:36:35AM -0500, Konrad Rzeszutek Wilk wrote:
> >> > 
> >> > In my new test setup, I have seen some strange behaviour. 1 of the HVM's
> >> > (with identical config in dom0 and domU) suddenly would not allow the
> >> > igb driver to be loaded in domU, even though the device was visible in
> >> 
> >> Let's create a new thread for this other issue.
> >> 
> >> > lspci. Shutting the machine down, removing the power cord, waiting 5
> >> > seconds then plugging it in again corrected that issue - Is this
> >> > possibly a motherboard bug? I have also disabled the SR-IOV
> >> > functionality in the BIOS incase this is causing any issues.
> >> > 
> >> > In addition, to try to correct the MSI issue noted above, I have changed
> >> > my pci= line to the following:
> >> > 
> >> > pci=[ '08:00.0,msitranslate=0', '08:00.1,msitranslate=0' ]
> >> 
> >> With the msi_translate=1 turned on the DomU HVM guests did work, right?
> >> 
> >> > 
> >> > This has stopped the "already in use on device" log, and the devices
> >> > appear to show correctly in the domU. Is it safe to disable
> >> > msitranslate? as I understand it, its for allowing multifunction devices
> >> > to be seen as such in domU. Is that correct?
> >> > 
> >> > I haven't been able to reproduce the dropped raid issue yet, but I am
> >> > awaiting delivery of the Red-Fone boxes (ISDN VoIP) which seem to cause
> >> > this due to their very high interrupt usage (2000 per second).
> >> 
> >> OK.
> >> > 
> >> > In the mean time, I can see the following in the qemu-dm logs now with
> >> > the msitranslate=0 enabled. Is it anything to worry about?
> >> 
> >> Well, the  "Error" ones are pretty bad, thought I am having a hard time
> >> understanding what it means. Lets copy some of the QEMU folks on this.
> >> 
> >> > pt_pci_write_config: Warning: Guest attempt to set address to unused 
> >> > Base Address Register. [00:05.0][Offset:14h][Length:4]
> >> > pt_ioport_map: e_phys=ffff pio_base=e880 len=32 index=2 first_map=0
> >> > pt_ioport_map: e_phys=c220 pio_base=e880 len=32 index=2 first_map=0
> >> > pt_pci_write_config: Warning: Guest attempt to set address to unused 
> >> > Base Address Register. [00:06.0][Offset:14h][Length:4]
> >> > pt_ioport_map: e_phys=ffff pio_base=ec00 len=32 index=2 first_map=0
> >> > pt_ioport_map: e_phys=c240 pio_base=ec00 len=32 index=2 first_map=0
> >> > pt_msix_update_one: Update msix entry 0 with pirq 4f gvec 59
> >> > pt_msix_update_one: Update msix entry 1 with pirq 4e gvec 61
> >> > pt_msix_update_one: Update msix entry 2 with pirq 4d gvec 69
> >> > pt_msix_update_one: Update msix entry 3 with pirq 4c gvec 71
> >> > pt_msix_update_one: Update msix entry 4 with pirq 4b gvec 79
> >> > pci_msix_writel: Error: Can't update msix entry 0 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 0 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 0 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 1 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 1 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 1 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 2 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 2 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 2 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 3 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 3 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 3 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 4 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 4 since MSI-X is already 
> >> > function.
> >> > pci_msix_writel: Error: Can't update msix entry 4 since MSI-X is already 
> >> > function.
> >> > 
> >> > > 
> >> > > Not yet. Need to serial log of the Linux kernel and the Xen hypervisor 
> >> > > when your
> >> > > machine is toast. I mentioned in the previous email the key sequences 
> >> > > - look on Google
> >> > > on how to pass in SysRQ if you are using a serial concentrator.
> >> > 
> >> > I will do this when I can get the machine to crash.
> >> > 
> >> > Best Regards,
> >> > Mark
> >> > 
> >> > _______________________________________________
> >> > Xen-devel mailing list
> >> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> >> > http://lists.xensource.com/xen-devel
> 
> 
> 
> 
> 
> -- 
> Best regards,
>  Sander                            mailto:linux@xxxxxxxxxxxxxx
> 

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