On Sat, Aug 07, 2021, Paolo Bonzini wrote: > Do not bother removing the low bits of the gpa. This masking dates back > to the very first commit of KVM but it is unnecessary---or even > problematic, because the gpa is later used to fill in the MMIO page cache. I don't disagree with the code change, but I don't see how stripping the offset can be problematic for the MMIO page cache. I assume you're referring to handle_abnormal_pfn() -> vcpu_cache_mmio_info(). The "gva" is masked with PAGE_MASK, i.e. the offset is stripped anyways. And fundamentally, that cache is tied to the granularity of the memslots, tracking the offset would be wrong.
