Hi again, Thanks a lot for investigating. I've reported the issue to the manufacturer.
Thanks, sarnex On Sat, Sep 17, 2016 at 5:35 PM, Alex Williamson < alex.l.william...@gmail.com> wrote: > On Sat, Sep 17, 2016 at 12:29 PM, Nick Sarnie <commendsar...@gmail.com> > wrote: > >> Hi Alex, >> >> The output is here: http://pastebin.com/raw/qjnpuaVr >> > > Ok, you need to go complain to your motherboard manufacturer, they're the > ones hiding the ACS capability. PCIe capabilities always start at 0x100, > the dword there is: > > 100: 01 00 01 22 = 0x22010001 > > Breaking that down, the capability at 0x100 is ID 0x0001 (AER), version > 0x1, and the next capability is at 0x220. So we do the same there: > > 220: 19 00 01 00 = 0x00010019 > > Capability ID 0x0019 (Secondary PCIe), version 0x1, next capability 0x0, > terminating the capability list. > > Per Intel documentation for the chipset (http://www.intel.com/content/ > www/us/en/chipsets/100-series-chipset-datasheet-vol-2.html), the ACS > capability and control registers live at 0x144 and 0x148 respectively and > we can see that you do have data here matching the default value of the > capability register: > > 140: 00 00 00 00 0f 00 00 00 00 00 00 00 00 00 00 00 > > ie. default value of 0x144 is 0xf. It appears that this BIOS vendor > didn't connect the capability into the chain or fill in the capability > header. The registers to do this are RW/O, ie. Read-Write-Once. IOW, the > registers can only be written once, which is intended to be used by the > BIOS. The capability bits themselves are RW/O, allowing vendors to expose > different sets of ACS capabilities. Given that this vendor has not exposed > the capability, we have no basis to believe that the default value of the > register represents the real capabilities of the system and therefore we > cannot assume we're able to control ACS. File a bug with the vendor or > look for a BIOS update where they may have already fixed this. > > >> Also, is there any way we could move the USB controller into its own >> group, or remove the Ethernet and SATA controller into a seperate group? >> Ideally, I could pass the USB Controller in group 7 without the ACS patch. >> > > That's not how IOMMU groups works. See http://vfio.blogspot.com/ > 2014/08/iommu-groups-inside-and-out.html We aren't creating these groups > arbitrarily, we base them on the information provided to use by the IOMMU > driver and PCI topology features, including ACS. If we cannot determine > that there is isolation between components, we must assume that they are > not isolated. Your choices are to run an unsupported (and unsupportable) > configuration using the ACS override patch, get your hardware vendor to fix > their platform, or upgrade to better hardware with better isolation > characteristics. >
_______________________________________________ vfio-users mailing list vfio-users@redhat.com https://www.redhat.com/mailman/listinfo/vfio-users
