Commit f285c633 authored Mar 12, 2019 by Ben Gardon Committed by Paolo Bonzini Mar 28, 2019

kvm: mmu: Used range based flushing in slot_handle_level_range

Replace kvm_flush_remote_tlbs with kvm_flush_remote_tlbs_with_address
in slot_handle_level_range. When range based flushes are not enabled
kvm_flush_remote_tlbs_with_address falls back to kvm_flush_remote_tlbs.

This changes the behavior of many functions that indirectly use
slot_handle_level_range, iff the range based flushes are enabled. The
only potential problem I see with this is that kvm->tlbs_dirty will be
cleared less often, however the only caller of slot_handle_level_range that
checks tlbs_dirty is kvm_mmu_notifier_invalidate_range_start which
checks it and does a kvm_flush_remote_tlbs after calling
kvm_unmap_hva_range anyway.

Tested: Ran all kvm-unit-tests on a Intel Haswell machine with and
without this patch. The patch introduced no new failures.

Signed-off-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

parent 3d9683cf

arch/x86/kvm/mmu.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -5526,7 +5526,9 @@ slot_handle_level_range(struct kvm kvm, struct kvm_memory_slot memslot,

		if (need_resched() \|\| spin_needbreak(&kvm->mmu_lock)) {
		if (flush && lock_flush_tlb) {
		kvm_flush_remote_tlbs(kvm);
		kvm_flush_remote_tlbs_with_address(kvm,
		start_gfn,
		iterator.gfn - start_gfn + 1);
		flush = false;
		}
		cond_resched_lock(&kvm->mmu_lock);
		@@ -5534,7 +5536,8 @@ slot_handle_level_range(struct kvm kvm, struct kvm_memory_slot memslot,
		}

		if (flush && lock_flush_tlb) {
		kvm_flush_remote_tlbs(kvm);
		kvm_flush_remote_tlbs_with_address(kvm, start_gfn,
		end_gfn - start_gfn + 1);
		flush = false;
		}