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| author | Andres Lagar-Cavilla <andreslc@google.com> | 2014-09-22 14:54:42 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-09-24 14:07:58 +0200 |
| commit | 57128468080a8b6ea452223036d3e417f748af55 (patch) | |
| tree | e89cfc349a9c39710cfab4e387119365a0d64958 /mm/rmap.c | |
| parent | 8a9522d2fe6a1b643d3aef5ab7f097f73c601e7a (diff) | |
| download | lwn-57128468080a8b6ea452223036d3e417f748af55.tar.gz lwn-57128468080a8b6ea452223036d3e417f748af55.zip | |
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 <andreslc@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 3e8491c504f8..bc74e0012809 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. */ |