From 57128468080a8b6ea452223036d3e417f748af55 Mon Sep 17 00:00:00 2001 From: Andres Lagar-Cavilla Date: Mon, 22 Sep 2014 14:54:42 -0700 Subject: kvm: Fix page ageing bugs 1. We were calling clear_flush_young_notify in unmap_one, but we are within an mmu notifier invalidate range scope. The spte exists no more (due to range_start) and the accessed bit info has already been propagated (due to kvm_pfn_set_accessed). Simply call clear_flush_young. 2. We clear_flush_young on a primary MMU PMD, but this may be mapped as a collection of PTEs by the secondary MMU (e.g. during log-dirty). This required expanding the interface of the clear_flush_young mmu notifier, so a lot of code has been trivially touched. 3. In the absence of shadow_accessed_mask (e.g. EPT A bit), we emulate the access bit by blowing the spte. This requires proper synchronizing with MMU notifier consumers, like every other removal of spte's does. Signed-off-by: Andres Lagar-Cavilla Acked-by: Rik van Riel Signed-off-by: Paolo Bonzini --- mm/rmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'mm/rmap.c') diff --git a/mm/rmap.c b/mm/rmap.c index 3e8491c..bc74e00 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1355,7 +1355,11 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount, continue; /* don't unmap */ } - if (ptep_clear_flush_young_notify(vma, address, pte)) + /* + * No need for _notify because we're within an + * mmu_notifier_invalidate_range_ {start|end} scope. + */ + if (ptep_clear_flush_young(vma, address, pte)) continue; /* Nuke the page table entry. */ -- cgit v1.1