Am 12.12.2014 um 23:21 schrieb Alex Williamson: > On Fri, 2014-12-12 at 22:38 +0100, Peter Lieven wrote: >> Hi, >> >> we have a Cisco UCS infrastructure where we have fnic Fibre-Channel Adapters >> that we expose to guests. The UCS >> infrastruture allows to create virtual HBAs that can be exposed to a host so >> its possible to have quite a lot of them. >> >> We ran into a strange issue when we started having more than one vServer >> with a FibreChannel Adapter passed >> thru with vfio-pci. >> >> When a hypervisor shuts down it the kernel sees the following error: >> >> pcieport 0000:00:07.0: AER: Uncorrected (Non-Fatal) error received: id=0038 >> pcieport 0000:00:07.0: PCIe Bus Error: severity=Uncorrected (Non-Fatal), >> type=Transaction Layer, id=0038(Receiver ID) >> pcieport 0000:00:07.0: device [8086:340e] error >> status/mask=00200000/00100000 >> pcieport 0000:00:07.0: [21] Unknown Error Bit (First) >> pcieport 0000:00:07.0: broadcast error_detected message >> pcieport 0000:00:07.0: AER: Device recovery failed >> >> Bit 21 seems to be ACS Violation. And 0000:00:07.0 is the PCIE Root Port on >> that System. >> >> This wouldn't be a big problem, altough I would like to find out what the >> ACS Violation causes. >> >> The real problem is that all other vfio-pci cards on that root port get >> notified of this error and the connected vServers are suspended >> with RUN_STATE_INTERNAL_ERROR. >> >> Any ideas to work around this other than hacking qemu to not register an >> error handler or modifying vfio_err_notifier_handler >> to not suspend the vServer? > You could set bit 21 in the AER uncorrected error mask register to avoid > the root port signaling the error. Is bit 21 already clear in the > severity register to make this non-fatal?
Can you give me a hint where I find those registers and how I mangle them? At least the syslog output states non-fatal. I am not that familiar with PCI internals, I am more the Block Layer guy. > >> Is it correct that all children of a root port are notified? Should qemu >> distinguish between fatal and non-fatal errors when >> suspending a vServer? > Yes, each child is notified. QEMU only gets an eventfd signal, which is > supposed to occur only for fatal errors. I don't quite understand why > this apparently non-fatal error is getting through. The kernel-side > VFIO code is where filtering of fatal vs non-fatal should occur. I will look at that. Has there been any bugfix since 3.13 ? Peter
