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Re: [vfio-users] choosing motherboard/chipset, hardware compatibility lists




On 03/03/16 14:13, Alex Williamson wrote:
> On Thu, Mar 3, 2016 at 6:36 AM, Daniel Pocock <daniel pocock pro
> <mailto:daniel pocock pro>> wrote:
> 
> 
> 
>     On 03/03/16 13:15, Alex Williamson wrote:
>     > On Thu, Mar 3, 2016 at 5:33 AM, Daniel Pocock <daniel pocock pro <mailto:daniel pocock pro>
>     > <mailto:daniel pocock pro <mailto:daniel pocock pro>>> wrote:
>     >
>     >
>     >
>     >     After the problems with the Intel 55x0 chipset, I've been looking at how
>     >     to choose something that is more likely to work
>     >
>     >     I came across some lists maintained in various places:
>     >
>     >     https://en.wikipedia.org/wiki/List_of_IOMMU-supporting_hardware
>     >       (mentions the C612 chipset but not the earlier C602?)
>     >
>     >     https://docs.google.com/spreadsheets/d/1LnGpTrXalwGVNy0PWJDURhyxa3sgqkGXmvNCIvIMenk/edit?pref=2&pli=1#gid=0
>     >
>     >     http://support.citrix.com/article/CTX131385
>     >     (this says HP Z800 is supported, but maybe they were testing one with
>     >     the newer 5520 C2 chipset)
>     >
>     >     https://www.vmware.com/resources/compatibility/search.php?deviceCategory=io
>     >
>     >     http://www.odin.com/support/extreme/
>     >        (mentions a few chipsets)
>     >
>     >     Are there any others that people consider useful for KVM VGA
>     >     passthrough?
>     >
>     >
>     >  http://vfio.blogspot.com/2015/10/intel-processors-with-acs-support.html
>     >
>     > VT-d is more in the processor than the chipset these days.  Picking the
>     > right processor will automatically pick the right chipset, which will be
>     > X79/X99 (or equivalent C-series) based.
>     >
> 
> 
>     Thanks for this feedback
> 
>     X79 is Patsburg, appears to be equivalent[1] to C602  (HP Z420,
>     Z620, Z820)
> 
>     X99 is Wellsburg, appears to be equivalent[2] to C612 (HP Z440,
>     Z640, Z840)
> 
>     Your blog comments on the features moving from chipset to CPU.  Does
>     that mean that BIOS and motherboard manufacturer have less impact on
>     success as well, or these are still strong factors?
> 
>     Is there anything you would consider to be a compelling reason to use
>     Wellsburg-based chipsets, or if I locate a box from the Patsburg era
>     that should suffice?
> 
> 
> I suspect that since we've gotten past vendors actually providing an
> option to enable VT-d, there's very little they can do to screw it up,
> other than place RMRR requirements on devices (which is generally not a
> problem if you don't have an HP iLO).  I have a Z820 that works just
> fine for device assignment and I test it regularly with Quadro VMs.  I
> also have an X58 (Tylersburg ~5520) which is subject to the interrupt
> remapping issue and it also works just fine, so long as you opt-in to
> the isolation risks associated with lack of interrupt remapping.  I

OK, so the interrupt remapping issue is not a showstopper and may not be
the root cause of the problems I've seen on the Z800 and it may still
work somehow?

Is there any specific setting you use on the X58 to compensate for the
issue, on the kernel command line, module options or the qemu command line?

Is your X58 chipset the B2, B3 or the later C2 stepping[1]?  E.g. this
is what I see on the 5520 B3 chipset:

$ lspci -nn | grep -E '8086:(340[36].*rev 13|3405.*rev (12|13|22))'
00:00.0 Host bridge [0600]: Intel Corporation 5520 I/O Hub to ESI Port
[8086:3406] (rev 13)


> don't know of any feature that you'll see specifically related to VT-d
> in Patsburg vs Wellsburg, both have quirks for exposing ACS-equivalent
> isolation in the PCH root ports, though Wellsburg came later (v4.0) and
> therefore might need a newer kernel than Patsburg (v3.16).  Thanks,
>

Thanks for all this feedback, if you have a moment, could you also
comment on my query about primary display last week?
https://www.redhat.com/archives/vfio-users/2016-February/msg00157.html
 (Subject: designating primary display during boot?)
https://www.redhat.com/archives/vfio-users/2016-February/msg00158.html
 (Subject: issues with secondary display configurations)

Regards,

Daniel


1. http://www.intel.com/Assets/PDF/specupdate/320839.pdf


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