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    SubjectRe: [PATCH v2 02/16] KVM: arm64: Check for PTE valitity when checking for executable/cacheable

    Hi Marc,

    sed s/valitity/validity/ <<<"$SUBJECT"

    On Mon, Oct 04, 2021 at 06:48:35PM +0100, Marc Zyngier wrote:
    > Don't blindly assume that the PTE is valid when checking whether
    > it describes an executable or cacheable mapping.
    >
    > This makes sure that we don't issue CMOs for invalid mappings.
    >
    > Suggested-by: Will Deacon <will@kernel.org>
    > Signed-off-by: Marc Zyngier <maz@kernel.org>
    > ---
    > arch/arm64/kvm/hyp/pgtable.c | 9 ++++-----
    > 1 file changed, 4 insertions(+), 5 deletions(-)
    >
    > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
    > index f8ceebe4982e..6bbfd952f0c5 100644
    > --- a/arch/arm64/kvm/hyp/pgtable.c
    > +++ b/arch/arm64/kvm/hyp/pgtable.c
    > @@ -638,12 +638,12 @@ static void stage2_put_pte(kvm_pte_t *ptep, struct kvm_s2_mmu *mmu, u64 addr,
    > static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte)
    > {
    > u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR;
    > - return memattr == KVM_S2_MEMATTR(pgt, NORMAL);
    > + return kvm_pte_valid(pte) && memattr == KVM_S2_MEMATTR(pgt, NORMAL);
    > }
    >
    > static bool stage2_pte_executable(kvm_pte_t pte)
    > {
    > - return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN);
    > + return kvm_pte_valid(pte) && !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN);
    > }
    >
    > static bool stage2_leaf_mapping_allowed(u64 addr, u64 end, u32 level,
    > @@ -688,8 +688,7 @@ 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);
    > -
    > + granule);
    > if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
    > mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);
    >
    > @@ -1091,7 +1090,7 @@ static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
    > kvm_pte_t pte = *ptep;
    > kvm_pte_t *pte_follow;
    >
    > - if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte))
    > + if (!stage2_pte_cacheable(pgt, pte))
    > return 0;
    >
    > pte_follow = kvm_pte_follow(pte, mm_ops);
    > --
    > 2.30.2
    >

    Reviewed-by: Andrew Jones <drjones@redhat.com>

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