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@xxxxxxxxxx>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxx>
