From: Suzuki K Poulose <suzuki.poul...@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: sta...@vger.kernel.org
Fixes: commit 293f29363 ("kvm-arm: Unmap shadow pagetables properly")
Reported-by: Alex Graf <ag...@suse.de>
Reviewed-by: Christoffer Dall <cd...@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
Signed-off-by: Marc Zyngier <marc.zyng...@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 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

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

Reply via email to