linux-kernel - [PATCH v6 01/18] kvm: arm/arm64: Fix stage2_flush

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Date:   Wed, 26 Sep 2018 17:32:37 +0100
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     linux-arm-kernel@...ts.infradead.org
Cc:     kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org,
        marc.zyngier@....com, cdall@...nel.org, eric.auger@...hat.com,
        suzuki.poulose@....com, will.deacon@....com, dave.martin@....com,
        peter.maydell@...aro.org, pbonzini@...hat.com, rkrcmar@...hat.com,
        julien.grall@....com, linux-kernel@...r.kernel.org
Subject: [PATCH v6 01/18] kvm: arm/arm64: Fix stage2_flush_memslot for 4 level page table

So far we have only supported 3 level page table with fixed IPA of
40bits, where PUD is folded. With 4 level page tables, we need
to check if the PUD entry is valid or not. Fix stage2_flush_memslot()
to do this check, before walking down the table.

Acked-by: Christoffer Dall <cdall@...nel.org>
Acked-by: Marc Zyngier <marc.zyngier@....com>
Reviewed-by: Eric Auger <eric.auger@...hat.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
---
 virt/kvm/arm/mmu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index ed162a6c57c5..ee7ce8fa4a12 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -412,7 +412,8 @@ static void stage2_flush_memslot(struct kvm *kvm,
 	pgd = kvm->arch.pgd + stage2_pgd_index(addr);
 	do {
 		next = stage2_pgd_addr_end(addr, end);
-		stage2_flush_puds(kvm, pgd, addr, next);
+		if (!stage2_pgd_none(*pgd))
+			stage2_flush_puds(kvm, pgd, addr, next);
 	} while (pgd++, addr = next, addr != end);
 }
 
-- 
2.19.0