Hi Kevin, On Thu, May 15, 2025 at 09:05:11PM -0700, Nicolin Chen wrote: > On Fri, May 16, 2025 at 03:52:16AM +0000, Tian, Kevin wrote: > > But hey, we are already adding various restrictions to the uAPI > > about dependency, contiguity, etc. which the VMM should conform > > to. What hurts if we further say that the VMM should allocate > > virtual index in an ascending order along with hw queue allocation? > > You mean adding another flag to manage the dependency in the core, > right? > > I talked with Jason offline when adding that depend API. He didn't > want it to be in the core, saying that is a driver thing. > > But that was before we added pin and contiguity, which he doesn't > really enjoy being in the core either. > > So, yea, I think you have a point here..
It seems Jason is out of office. And in the last sync w.r.t this, he thinks that this ascending order stuff is too unique/weird to make sense as a feature in the core, that there would be unlikely a second HW wanting this.. I think that's a valid point too. The pin/contiguity requirement at least serves for HW that reads in physical address space, and it could result in a slightly faster memory access since it does not need a translation, which though gives software some trouble yet still makes sense IMHO. So, in v5, I kept the dependency APIs rather than moving to the core. I think we can move to the core later if we see another HW doing the same thing. Thanks Nicolin
