Re: [PATCH v2 03/16] iommu: introduce iommu invalidate API function

[Joerg Roedel]

On Wed, Oct 11, 2017 at 07:54:32AM +0000, Liu, Yi L wrote:
> I agree that iommu_invalidate() is too generic. Additionally, also
> better to avoid making it svm specific.

I also don't like to name the functions after the Intel feature, but I
failed to come up with a better alternative so far. The only one I can
come up with for now would be 'iovm', so the function name would be
iommu_iovm_invalidate().

On the other side, the ARM guys also already call the feature set
'SVM', despite it being ambiguous and Intel specific. I don't have a
strong opinion on the naming.

> The reason we introduce this API is in vSVM case is that guest owns
> the first level page table(vtd). If we use similar mechanism for
> vIOVA, then we also need to passdown guest's vIOVA tlb flush.
> 
> Since it is to expose an API for iommu tlb flushes requests from
> userspace/guest which is out of iommu. How about naming it as
> iommu_tlb_external_invalidate()?

If you only read the function name, 'external' could mean everything. It
is not clear from the name when to use this function. So something like
iommu_iovm_invalidate() is better.


	Joerg