[vfio-users] Help fixing iommu group

[Alex Williamson]

On Wed, 17 Feb 2016 20:57:34 +0100
thibaut noah <thibaut.noah at gmail.com> wrote:

> Hello, i finally received an hba card for my zfs raid and the card is off
> course breaking iommu grouping.
> I tried the 2pci ports i had left (gpu in the first one) but the hba card
> is always in group 1.
> I tried several options in grub to override acs but that didn't change
> anything (had downstream set before, added other options).
> Could someone point me to a documentation or something to fix this? i
> cannot use my vm at all
> Here is a paste of the error i get :
> 
> http://fpaste.org/324296/45573902/
> 
> paste of grub file :
> http://fpaste.org/324284/45573856/
> 
> paste of ls -lha /sys/bus/pci/devices/0000:01:00.0/iommu_group/devices :
> http://fpaste.org/324283/38515145/
> 
> here is a paste of lspci -vvvnn :
> http://fpaste.org/324281/55738407/
> 
> Any help would be gladly appreciated thanks

First, are you using a kernel that's patched with the pcie_acs_override
option?  It's not upstream.  You also have:

pcie_acs_override=downstream,id:103c:21c7,boot

103c:21c7 is the subsystem ID of your HBA, it's a single function
endpoint, so that entry is useless on a couple fronts.  'boot' is not a
valid option, maybe you ran into another option?

pcie_acs_override=downstream

should be sufficient, if you want to use id, it's the IDs of the root
ports, for example:

pcie_acs_override=id:8086:0c01,id:8086:0c09

But of course nothing happens till the kernel is patched.