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authorPaul Mackerras <paulus@samba.org>2012-11-19 23:01:34 +0000
committerAlexander Graf <agraf@suse.de>2012-12-06 01:33:53 +0100
commit4879f241720cda3e6c18a1713bf9b2ed2de14ee4 (patch)
tree300a9282556b3e441b9747dee4b5e51d440986fe
parent7ed661bf852cefa1ab57ad709a675bfb029d47ab (diff)
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KVM: PPC: Book3S HV: Fix bug causing loss of page dirty state
This fixes a bug where adding a new guest HPT entry via the H_ENTER hcall would lose the "changed" bit in the reverse map information for the guest physical page being mapped. The result was that the KVM_GET_DIRTY_LOG could return a zero bit for the page even though the page had been modified by the guest. This fixes it by only modifying the index and present bits in the reverse map entry, thus preserving the reference and change bits. We were also unnecessarily setting the reference bit, and this fixes that too. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
-rw-r--r--arch/powerpc/kvm/book3s_hv_rm_mmu.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 362dffe4db1..ff2da5ce475 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -59,10 +59,10 @@ void kvmppc_add_revmap_chain(struct kvm *kvm, struct revmap_entry *rev,
head->back = pte_index;
} else {
rev->forw = rev->back = pte_index;
- i = pte_index;
+ *rmap = (*rmap & ~KVMPPC_RMAP_INDEX) |
+ pte_index | KVMPPC_RMAP_PRESENT;
}
- smp_wmb();
- *rmap = i | KVMPPC_RMAP_REFERENCED | KVMPPC_RMAP_PRESENT; /* unlock */
+ unlock_rmap(rmap);
}
EXPORT_SYMBOL_GPL(kvmppc_add_revmap_chain);