From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 3 Aug 2017 16:28:56 +0100 Subject: [PATCH 3/4] KVM: arm/arm64: Handle hva aging while destroying the vm In-Reply-To: <20170803152857.32055-1-marc.zyngier@arm.com> References: <20170803152857.32055-1-marc.zyngier@arm.com> Message-ID: <20170803152857.32055-4-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Suzuki K Poulose 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 at vger.kernel.org Fixes: commit 293f29363 ("kvm-arm: Unmap shadow pagetables properly") Reported-by: Alex Graf Reviewed-by: Christoffer Dall Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier --- 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 0e1fc75f3585..2ea21dac0b44 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); } -- 2.11.0