From 628212c89faeed34704977a0edcfaaaae467a34d Mon Sep 17 00:00:00 2001
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: Tue, 16 May 2017 10:34:54 +0100
Subject: [PATCH] kvm: arm/arm64: Force reading uncached stage2 PGD

commit 2952a6070e07ebdd5896f1f5b861acad677caded upstream.

Make sure we don't use a cached value of the KVM stage2 PGD while
resetting the PGD.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/arm/kvm/mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 9b8a0ba33c9d..e8835d4e173c 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -833,7 +833,7 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
 	spin_lock(&kvm->mmu_lock);
 	if (kvm->arch.pgd) {
 		unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
-		pgd = kvm->arch.pgd;
+		pgd = READ_ONCE(kvm->arch.pgd);
 		hwpgd = kvm_get_hwpgd(kvm);
 		kvm->arch.pgd = NULL;
 	}