Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [patch V2 31/33] iommu/vt-d: Enable PCI/IMS | Date | Thu, 24 Nov 2022 14:21:04 +0100 |
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On Thu, Nov 24 2022 at 09:14, Jason Gunthorpe wrote: > On Thu, Nov 24, 2022 at 10:37:53AM +0100, Thomas Gleixner wrote: >> Jason said, that the envisioned Mellanox use case does not depend on the >> IOMMU because the card itself has one which takes care of the >> protections. > > Right, but that doesn't mean we need the physical iommu turned > off. Setting the mlx pci device to identity mode is usually enough to > get back to full performance.
Ok.
>> How are we going to resolve that dilemma? > > The outcome is we don't have a strategy right now to make IMS work in > VMs. This series is all about making it work on physical machines, > that has to be a good first step. > > I'm hoping the OCP work stream on SIOV will tackle how to fix the > interrupt problems. Some of the ideas I've seen could be formed into > something that would work in a VM.
Fair enough.
Let me put the limitation into effect then.
Thanks,
tglx
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