I regularly grind on all sorts of HSS and Carbide, as I do tool & cutter grinding on the side.
You can grind on most types of HSS using a standard aluminum oxide grinding belt, or wheel. I use the belts on a regular basis to bark off heavy damage, then to the T & C grinder to finish the job. The belt sander minimizes the heat build up in the tool, and removes the most material quickly. (Of course, all you experienced knifemakers know this)
The wheels I use are mostly CBN (Cubic Boron Nitride) for grinding the HSS, but when I re do the ends on end mills, or sharpen drills, and sharpen hog end mills, I use an aluminum oxide wheel for the best results. Of course, Carbide gets the PCD wheels (Poly Chrystalline Diamond), or depending on the type of carbide too, I will use a SiC wheel. (Silicon Carbide)
In short, almost all HSS will make a decent knife. It is tough enough, impact resistant, and abrasive resistant, and holds an edge quite well. Just use some sort of protectant, as it WILL rust!!!
I'm currently 'working' on a knife project using a chunk of M-42 HSS (high cobalt content), and I'm doing it on a belt grinder. So far, so good. I'll finish it someday, I hope!!!
Also, before I forget, don't try to forge or heat HSS that already has been heat treated. Eric already has learned that you cannot forge already hardened HSS.