Re: [PATCH v2 2/4] vfio: Move the Intel no-snoop control off of IOMMU_CACHE

Jason Gunthorpe
2022-04-11T14:13:40Z

On Fri, Apr 08, 2022 at 09:47:57AM -0600, Alex Williamson wrote:

> > Ultimately VFIO plumbs the result of enforce_cache_coherency() back into
> > the x86 platform code through kvm_arch_register_noncoherent_dma() which
> > controls if the WBINVD instruction is available in the guest. No other
> > arch implements kvm_arch_register_noncoherent_dma().
>
> I think this last sentence is alluding to it, but I wish the user
> visible change to VFIO_DMA_CC_IOMMU on non-x86 were more explicit.
> Perhaps for the last sentence:
>
> No other archs implement kvm_arch_register_noncoherent_dma() nor are
> there any other known consumers of VFIO_DMA_CC_IOMMU that might be
> affected by the user visible result change on non-x86 archs.

Done

Thanks,
Jason