Now that the fast invalidate mechanism has been reintroduced, restore
the performance tweaks for fast invalidation that existed prior to its
removal.
Paraphrasing the original changelog (commit 5ff0568374 was itself a
partial revert):
Don't force reloading the remote mmu when zapping an obsolete page, as
a MMU_RELOAD request has already been issued by kvm_mmu_zap_all_fast()
immediately after incrementing mmu_valid_gen, i.e. after marking pages
obsolete.
This reverts commit 5ff0568374.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>