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From:   Marc Zyngier <maz@kernel.org>
To:     linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     will@kernel.org, qperret@google.com, dbrazdil@google.com,
        Srivatsa Vaddagiri <vatsa@codeaurora.org>,
        Shanker R Donthineni <sdonthineni@nvidia.com>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        kernel-team@android.com
Subject: [PATCH 02/16] KVM: arm64: Don't issue CMOs when the physical address is invalid
Date:   Thu, 15 Jul 2021 17:31:45 +0100
Message-Id: <20210715163159.1480168-3-maz@kernel.org>
In-Reply-To: <20210715163159.1480168-1-maz@kernel.org>
References: <20210715163159.1480168-1-maz@kernel.org>
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Make sure we don't issue CMOs when mapping something that
is not a memory address in the S2 page tables.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/pgtable.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 05321f4165e3..a5874ebd0354 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -619,12 +619,16 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level,
 	}
 
 	/* Perform CMOs before installation of the guest stage-2 PTE */
-	if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new))
-		mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops),
-						granule);
-
-	if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
-		mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);
+	if (kvm_phys_is_valid(phys)) {
+		if (mm_ops->dcache_clean_inval_poc &&
+		    stage2_pte_cacheable(pgt, new))
+			mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new,
+								      mm_ops),
+						       granule);
+		if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
+			mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops),
+						 granule);
+	}
 
 	smp_store_release(ptep, new);
 	if (stage2_pte_is_counted(new))
-- 
2.30.2