Messages in this thread | | | Date | Thu, 10 May 2018 13:10:15 -0600 | From | Alex Williamson <> | Subject | Re: [PATCH v4 04/14] PCI/P2PDMA: Clear ACS P2P flags for all devices behind switches |
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On Thu, 10 May 2018 18:41:09 +0000 "Stephen Bates" <sbates@raithlin.com> wrote: > > Reasons is that GPU are giving up on PCIe (see all specialize link like > > NVlink that are popping up in GPU space). So for fast GPU inter-connect > > we have this new links. > > I look forward to Nvidia open-licensing NVLink to anyone who wants to use it ;-).
No doubt, the marketing for it is quick to point out the mesh topology of NVLink, but I haven't seen any technical documents that describe the isolation capabilities or IOMMU interaction. Whether this is included or an afterthought, I have no idea.
> > Also the IOMMU isolation do matter a lot to us. Think someone using this > > peer to peer to gain control of a server in the cloud.
From that perspective, do we have any idea what NVLink means for topology and IOMMU provided isolation and translation? I've seen a device assignment user report that seems to suggest it might pretend to be PCIe compatible, but the assigned GPU ultimately doesn't work correctly in a VM, so perhaps the software compatibility is only so deep. Thanks,
Alex
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