Re: [RFC PATCH 0/7] A General Accelerator Framework, WarpDrive

[Xu Zaibo]

Hi,

On 2018/8/2 18:10, Alan Cox wrote:
> > One motivation I guess, is that most accelerators lack of a
> > well-abstracted high level APIs similar to GPU side (e.g. OpenCL
> > clearly defines Shared Virtual Memory models). VFIO mdev
> > might be an alternative common interface to enable SVA usages
> > on various accelerators...
> SVA is not IMHO the hard bit from a user level API perspective. The hard
> bit is describing what you have and enumerating the contents of the device
> especially when those can be quite dynamic and in the FPGA case can
> change on the fly.
>
> Right now we've got
> - FPGA manager
> - Google's recently posted ASIC patches
> - WarpDrive
>
> all trying to be bits of the same thing, and really there needs to be a
> single solution that handles all of this stuff properly.
>
> If we are going to have any kind of general purpose accelerator API then
> it has to be able to implement things like
>
> 	'find me an accelerator with function X that is nearest my memory'
> 	'find me accelerator functions X and Y that share HBM'
> 	'find me accelerator functions X and Y than can be chained'
>
> If instead we have three API's depending upon whose accelerator you are
> using and whether it's FPGA or ASIC this is going to be a mess on a grand
> scale.
Agree, at the beginning, we try to bring a notion of 'capability' which 
describes 'algorithms, mem access methods .etc ',
but then, we come to realize it is the first thing that we should come 
to a single solution on these things such as
memory/device access, IOMMU .etc.

Thanks,
Zaibo

> .