Patch "kvm: arm/arm64: Force reading uncached stage2 PGD" has been added to the 4.11-stable tree

Patch "kvm: arm/arm64: Force reading uncached stage2 PGD" has been added to the 4.11-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    kvm: arm/arm64: Force reading uncached stage2 PGD

to the 4.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     kvm-arm-arm64-force-reading-uncached-stage2-pgd.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 2952a6070e07ebdd5896f1f5b861acad677caded 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: kvm: arm/arm64: Force reading uncached stage2 PGD

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

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm/kvm/mmu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -844,7 +844,7 @@ 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);
 		kvm->arch.pgd = NULL;
 	}
 	spin_unlock(&kvm->mmu_lock);


Patches currently in stable-queue which might be from suzuki.poulose@arm.com are

queue-4.11/kvm-arm-arm64-force-reading-uncached-stage2-pgd.patch
queue-4.11/kvm-arm-arm64-fix-race-in-resetting-stage2-pgd.patch
queue-4.11/kvm-arm-arm64-fix-use-after-free-of-stage2-page-table.patch