From b259d137e91d80bf92eac453ffab179eb7941ede Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 30 Sep 2020 14:18:01 +0100 Subject: [PATCH] KVM: arm64: Pass level hint to TLBI during stage-2 permission fault 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. Reported-by: Alexandru Elisei Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Reviewed-by: Alexandru Elisei Reviewed-by: Gavin Shan Cc: Marc Zyngier Link: https://lore.kernel.org/r/595cc73e-636e-8b3a-f93a-b4e9fb218db8@arm.com Link: https://lore.kernel.org/r/20200930131801.16889-1-will@kernel.org --- 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; } -- 2.11.0