libvirt users - Aug 2018 - Re: Trouble passing PCI device in isolated IOMMU group

I'm attempting PCI-passthrough from host to guest on an HP ProLiant 380P,
which has an outdated BIOS (2014), but it does support VT-d. I'm running
CentOS 7, kernel 3.10.0-862.9.1.el7.x86_64.

I have an Intel 82580 NIC installed with 4 ports. Each of these ports is in
its own IOMMU group (I enabled SR-IOV at the BIOS, which might be the
reason they show up separately)

 After detaching and adding a 'hostdev' device with the appropriate pci
address, I attempt to start my VM. I get " failed to set iommu for
container: Operation not permitted". As recommended here (
http://vfio.blogspot.com/2014/08/vfiovga-faq.html) I parsed dmesg in an
attempt to find:

-------------------
No interrupt remapping support. Use the module param
"allow_unsafe_interrupts" to enable VFIO IOMMU support on this
platform
-------------------
...but nothing similar exists in my logs.

Since this device is showing up in its own IOMMU group, I assume ACS
override won't get me any further. In any case, it is not an option for me
to leave ACS override on. I can turn it on for testing, the server is not
currently in production.

Any idea why this could be failing?

On 07/27/2018 11:51 AM, Quincy Wofford wrote:
> I'm attempting PCI-passthrough from host to guest on an HP ProLiant
> 380P, which has an outdated BIOS (2014), but it does support VT-d. I'm
> running CentOS 7, kernel 3.10.0-862.9.1.el7.x86_64.
> 
> I have an Intel 82580 NIC installed with 4 ports. Each of these ports is
> in its own IOMMU group (I enabled SR-IOV at the BIOS, which might be the
> reason they show up separately)
> 
>  After detaching and adding a 'hostdev' device with the appropriate
pci
> address, I attempt to start my VM. I get " failed to set iommu for
> container: Operation not permitted". As recommended here
> (http://vfio.blogspot.com/2014/08/vfiovga-faq.html) I parsed dmesg in an
> attempt to find:
> 
> -------------------
> No interrupt remapping support. Use the module param
> "allow_unsafe_interrupts" to enable VFIO IOMMU support on this
platform
> -------------------
> ...but nothing similar exists in my logs.
> 
> Since this device is showing up in its own IOMMU group, I assume ACS
> override won't get me any further. In any case, it is not an option for
> me to leave ACS override on. I can turn it on for testing, the server is
> not currently in production.
> 
> Any idea why this could be failing?
If you haven't yet found a solution to this problem, I would recommend
sending your question either to vfio-users@redhat.com, or asking in the
#vfio-users channel on  irc.freenode.net

Thanks for the tip!

On Mon, Aug 6, 2018 at 1:48 PM Laine Stump <laine@redhat.com> wrote:
> On 07/27/2018 11:51 AM, Quincy Wofford wrote:
> > I'm attempting PCI-passthrough from host to guest on an HP
ProLiant
> > 380P, which has an outdated BIOS (2014), but it does support VT-d.
I'm
> > running CentOS 7, kernel 3.10.0-862.9.1.el7.x86_64.
> >
> > I have an Intel 82580 NIC installed with 4 ports. Each of these ports
is
> > in its own IOMMU group (I enabled SR-IOV at the BIOS, which might be
the
> > reason they show up separately)
> >
> >  After detaching and adding a 'hostdev' device with the
appropriate pci
> > address, I attempt to start my VM. I get " failed to set iommu
for
> > container: Operation not permitted". As recommended here
> > (http://vfio.blogspot.com/2014/08/vfiovga-faq.html) I parsed dmesg in
an
> > attempt to find:
> >
> > -------------------
> > No interrupt remapping support. Use the module param
> > "allow_unsafe_interrupts" to enable VFIO IOMMU support on
this platform
> > -------------------
> > ...but nothing similar exists in my logs.
> >
> > Since this device is showing up in its own IOMMU group, I assume ACS
> > override won't get me any further. In any case, it is not an
option for
> > me to leave ACS override on. I can turn it on for testing, the server
is
> > not currently in production.
> >
> > Any idea why this could be failing?
>
> If you haven't yet found a solution to this problem, I would recommend
> sending your question either to vfio-users@redhat.com, or asking in the
> #vfio-users channel on  irc.freenode.net
>
>