[PULL 3/8] KVM: arm/arm64: Handle hva aging while destroying the vm

Christoffer Dall
2017-09-05T14:50:00Z

From: Suzuki K Poulose <Suzuki.Poulose@arm.com>

The mmu_notifier_release() callback of KVM triggers cleaning up
the stage2 page table on kvm-arm. However there could be other
notifier callbacks in parallel with the mmu_notifier_release(),
which could cause the call backs ending up in an empty stage2
page table. Make sure we check it for all the notifier callbacks.

Cc: stable@vger.kernel.org
Fixes: commit 293f29363 ("kvm-arm: Unmap shadow pagetables properly")
Reported-by: Alex Graf <agraf@suse.de>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
virt/kvm/arm/mmu.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 0e1fc75..2ea21da 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1718,12 +1718,16 @@ static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *

int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
{
+ if (!kvm->arch.pgd)
+ return 0;
trace_kvm_age_hva(start, end);
return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
}

int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
{
+ if (!kvm->arch.pgd)
+ return 0;
trace_kvm_test_age_hva(hva);
return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
}
--
2.9.0