On Thu, Sep 21, 2023, Xu Yilun wrote: > When the invalidation acrosses multiple slots, I'm not sure if the > contiguous HVA range must correspond to contiguous GFN range. If not, > are we producing a larger range than required?
Multiple invalidations are all but guaranteed to yield a range that covers addresses that aren't actually being invalidated. This is true today. > And when the invalidation acrosses multiple address space, I'm almost > sure it is wrong to merge GFN ranges from different address spaces. It's not "wrong" in the sense that false positives do not cause functional problems, at worst a false positive can unnecessarily stall a vCPU until the unrelated invalidations complete. Multiple concurrent invalidations are not common, and if they do happen, they are likely related and will have spacial locality in both host virtual address space and guest physical address space. Given that, we chose for the simple (and fast!) approach of maintaining a single all-encompassing range.
