[vfio-users] vfio, xeon e3s, acs, & gpus -- oh my!

[Joshua Hoblitt]

While Intel's various artificial market segmentation attempts are
irritating, my guess that ACS being absent from desktop oriented
products is more a case of a recycled PCIe design from haswell rather
than disabled silicon.  It is unfair to label an absent feature as
"iffy".  Broadwell-E is still the current generation core for E5/E7.  It
certainly will be disappointing if ACS is absent from kaby lake/coffee
lake but my understanding is that -E like E5/E7 variants of these cores
are planned.  My guess is that if there was a non-trivial desktop demand
for ACS the silicon would materialize.

That said, Intel has an excellent track record of supporting their
hardware (with the notable exception of AMT) under Linux and they are
consistently one of the largest overall Linux contributors. Their GPUs
and high end NICs "just work" and in the rare instances in which I've
encountered driver problems (Eg. early days of 10G NICS), patches were
quickly sent upstream.  This is commendable behavior for a vendor.

Perhaps if anyone on this list has contact(s) at Intel, they could reach
out and ask for clarification as to Intel's roadmap for ACS in desktop
oriented processors?

-Josh

--
On 04/02/2017 04:57 AM, Joshua Lee wrote:
> Your personal experience didn't make my CPU cost $2,000. Although
> Intel does a regrettable amount of market separation - it isn't quite
> that bad. 
>
>
> On Sun, Apr 2, 2017 at 5:18 AM, Taiidan at gmx.com
> <mailto:Taiidan at gmx.com> <Taiidan at gmx.com <mailto:Taiidan at gmx.com>> wrote:
>
>     On 04/02/2017 01:43 AM, Joshua Lee wrote:
>
>         What do you mean by "iffy"? My $200 x99 board has seperate
>         IOMMU groups
>         per-device, and a i7 5820k/6800k or, if you want it cheaper,
>         an E5-1620v3
>         or 1620v4, can do ACS and sane IOMMU groups with it for under
>         $600 also,
>         without needing to get a used processor...
>
>     Personal experience - I have never seen a reasonably priced intel
>     system that did it properly, whereas even AMD's "desktop" CPU's
>     and chipsets have it.
>
>     I don't buy or recommend intel's stuff for exotic uses because I
>     have been burned too many times by their artificial market
>     separation efforts, I also do not like the fact that their newer
>     products aren't owner controlled for a variety of reasons
>     (although now you can say the same about AMD as well) which again
>     isn't good for fringe uses as there is no ability to fix things
>     that the board vendor refuses to.
>
>     There isn't anything wrong with buying a used processor, and $150
>     gets you a 6386SE with 16 cores.
>
>