PageTable set incoherence: Page Fault, Page Walk, and Page Evictions modify non buffered set

[UlisesLuzius]

There's a architectural error:

When working on a PageTableSet (16 translation entries), we buffer the set inside the PageMissHandler module.

But, decisions on that module might trigger TLB evictions, and extra page walks.

Those decisions will not modify the buffered working set, but will actually refetch the set from DRAM and modify it there, making it such as the latest version of the set is not updated correctly.

See pic below, the page table set is full (FFFF) although we already evicted those entries previously.