diff mbox

KVM: PPC: Book3S HV: Add missing HPTE unlock

Message ID 1415150473-28458-1-git-send-email-paulus@samba.org
State New, archived
Headers show

Commit Message

Paul Mackerras Nov. 5, 2014, 1:21 a.m. UTC 
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

In kvm_test_clear_dirty(), 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@kernel.crashing.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/kvm/book3s_64_mmu_hv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Alexander Graf Nov. 20, 2014, 5:23 p.m. UTC | #1 
On 05.11.14 02:21, Paul Mackerras wrote:
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> In kvm_test_clear_dirty(), 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@kernel.crashing.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Signed-off-by: Paul Mackerras <paulus@samba.org>

Thanks, applied to kvm-ppc-queue.


Alex
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diff mbox

Patch

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index d407702..41f96c5 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -1117,8 +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);