[PATCH] KVM: PPC: Book3S HV: Add missing HPTE unlock

[Aneesh Kumar K.V]

In kvm_test_clear_dirty_npages(), if we find an invalid HPTE we move on to the
next HPTE without unlocking the invalid one.  In fact we should never
find an invalid and unlocked HPTE in the rmap chain, but for robustness
we should unlock it.  This adds the missing unlock.

Reported-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index d40770248b6a..cebb86bc4a37 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -1117,9 +1117,11 @@ static int kvm_test_clear_dirty_npages(struct kvm *kvm, unsigned long *rmapp)
 		}
 
 		/* Now check and modify the HPTE */
-		if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID)))
+		if (!(hptep[0] & cpu_to_be64(HPTE_V_VALID))) {
+			/* unlock and continue */
+			hptep[0] &= ~cpu_to_be64(HPTE_V_HVLOCK);
 			continue;
-
+		}
 		/* need to make it temporarily absent so C is stable */
 		hptep[0] |= cpu_to_be64(HPTE_V_ABSENT);
 		kvmppc_invalidate_hpte(kvm, hptep, i);
-- 
1.9.1