arm/arm64: KVM: Fix VTTBR_BADDR_MASK and pgd alloc

The current aarch64 calculation for VTTBR_BADDR_MASK masks only 39 bits
and not all the bits in the PA range. This is clearly a bug that
manifests itself on systems that allocate memory in the higher address
space range.

 [ Modified from Joel's original patch to be based on PHYS_MASK_SHIFT
   instead of a hard-coded value and to move the alignment check of the
   allocation to mmu.c.  Also added a comment explaining why we hardcode
   the IPA range and changed the stage-2 pgd allocation to be based on
   the 40 bit IPA range instead of the maximum possible 48 bit PA range.
   - Christoffer ]

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Joel Schopp <joel.schopp@amd.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 40bc3df6d87..779605122f3 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -410,9 +410,9 @@ static void update_vttbr(struct kvm *kvm)
 
 	/* update vttbr to be used with the new vmid */
 	pgd_phys = virt_to_phys(kvm->arch.pgd);
+	BUG_ON(pgd_phys & ~VTTBR_BADDR_MASK);
 	vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK;
-	kvm->arch.vttbr = pgd_phys & VTTBR_BADDR_MASK;
-	kvm->arch.vttbr |= vmid;
+	kvm->arch.vttbr = pgd_phys | vmid;
 
 	spin_unlock(&kvm_vmid_lock);
 }