[vfio-users] Help fixing iommu group

[Alex Williamson]

On Wed, 17 Feb 2016 23:02:18 +0100
thibaut noah <thibaut.noah at gmail.com> wrote:

> I thought the patch was already applied in the version of fedora i was
> using (4.2.3)

There is currently no expectation that the pcie_acs_override patch will
ever go upstream, thus my encouragement to use a system that properly
supports ACS.
 
> Nope, i thought this one meant boot was a valid option.
> "The pcie_acs_override= boot option lets users opt-in specific devices or
> sets of devices to assume ACS support."
> 
> My bad for the id.
> How does one apply the patch to the kernel?

https://www.kernel.org/doc/Documentation/applying-patches.txt


> 2016-02-17 22:07 GMT+01:00 Alex Williamson <alex.williamson at redhat.com>:
> 
> > 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.
> >