> Question is, can we even access a hwpoisoned page to retrieve that data > or are we completely in the wrong weeds here? Tony?
Hardware scope for poison is a cache line (64 bytes for DDR, may be larger for the internals of 3D-Xpoint memory). So you can access the other lines in the page. You just need to be careful not to access the poison. Setting the cache mode for the page to uncacheable ensures that h/w prefetchers and speculative access don't accidently touch the poison while accessing nearby cache lines. -Tony
