Hi, On 9/30/20 2:18 PM, Will Deacon wrote: > Alex pointed out that we don't pass a level hint to the TLBI instruction > when handling a stage-2 permission fault, even though the walker does > at some point have the level information in its hands. > > Rework stage2_update_leaf_attrs() so that it can optionally return the > level of the updated pte to its caller, which can in turn be used to > provide the correct TLBI level hint. Looks correct to me. I checked and all the functions that don't do a tlbi pass NULL as the level pointer, and the level parameter is always set by the walker algorithm (if level had an invalid value, no invalidation would have been performed): Reviewed-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> Thanks, Alex > > Cc: Marc Zyngier <maz@xxxxxxxxxx> > Link: https://lore.kernel.org/r/595cc73e-636e-8b3a-f93a-b4e9fb218db8@xxxxxxx > Reported-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> > Signed-off-by: Will Deacon <will@xxxxxxxxxx> > --- > arch/arm64/kvm/hyp/pgtable.c | 23 ++++++++++++++++------- > 1 file changed, 16 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 603d6b415337..0cdf6e461cbd 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -694,6 +694,7 @@ struct stage2_attr_data { > kvm_pte_t attr_set; > kvm_pte_t attr_clr; > kvm_pte_t pte; > + u32 level; > }; > > static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > @@ -706,6 +707,7 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > if (!kvm_pte_valid(pte)) > return 0; > > + data->level = level; > data->pte = pte; > pte &= ~data->attr_clr; > pte |= data->attr_set; > @@ -723,7 +725,8 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, > > static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, > u64 size, kvm_pte_t attr_set, > - kvm_pte_t attr_clr, kvm_pte_t *orig_pte) > + kvm_pte_t attr_clr, kvm_pte_t *orig_pte, > + u32 *level) > { > int ret; > kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI; > @@ -743,20 +746,24 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, > > if (orig_pte) > *orig_pte = data.pte; > + > + if (level) > + *level = data.level; > return 0; > } > > int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) > { > return stage2_update_leaf_attrs(pgt, addr, size, 0, > - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, NULL); > + KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, > + NULL, NULL); > } > > kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, > - &pte); > + &pte, NULL); > dsb(ishst); > return pte; > } > @@ -765,7 +772,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF, > - &pte); > + &pte, NULL); > /* > * "But where's the TLBI?!", you scream. > * "Over in the core code", I sigh. > @@ -778,7 +785,7 @@ kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) > bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) > { > kvm_pte_t pte = 0; > - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte); > + stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); > return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; > } > > @@ -786,6 +793,7 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, > enum kvm_pgtable_prot prot) > { > int ret; > + u32 level; > kvm_pte_t set = 0, clr = 0; > > if (prot & KVM_PGTABLE_PROT_R) > @@ -797,8 +805,9 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, > if (prot & KVM_PGTABLE_PROT_X) > clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; > > - ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL); > - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, 0); > + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); > + if (!ret) > + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level); > return ret; > } > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
