[PATCH v2 22/28] KVM: arm64: Set Access flag on table descriptors at stage-1

[Oliver Upton <oupton@kernel.org>]

Implement access flag updates on table descriptors as required by
FEAT_HAFT. Note that unlike leaf descriptors, access flags on table
descriptors never generate a fault.

Reviewed-by: Leonardo Bras <leo.bras@arm.com>
Signed-off-by: Oliver Upton <oupton@kernel.org>
---
 arch/arm64/include/asm/kvm_nested.h  |  1 +
 arch/arm64/include/asm/kvm_pgtable.h | 11 +++++++++++
 arch/arm64/kvm/at.c                  | 23 ++++++++++++++++-------
 arch/arm64/kvm/hyp/pgtable.c         | 11 -----------
 4 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 11944dfb204c..81d8b1676fe4 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -340,6 +340,7 @@ struct s1_walk_info {
 	bool			pa52bit;
 	bool			ha;
 	bool			hd;
+	bool			haft;
 };
 
 struct s1_walk_result {
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 23e93f14af7b..0912987ea21a 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -139,6 +139,17 @@ static inline bool kvm_pte_valid(kvm_pte_t pte)
 	return pte & KVM_PTE_VALID;
 }
 
+static inline bool kvm_pte_table(kvm_pte_t pte, s8 level)
+{
+	if (level == KVM_PGTABLE_LAST_LEVEL)
+		return false;
+
+	if (!kvm_pte_valid(pte))
+		return false;
+
+	return FIELD_GET(KVM_PTE_TYPE, pte) == KVM_PTE_TYPE_TABLE;
+}
+
 static inline u64 kvm_pte_to_phys(kvm_pte_t pte)
 {
 	u64 pa;
diff --git a/arch/arm64/kvm/at.c b/arch/arm64/kvm/at.c
index 2ce34af3b9f2..8f1be3af64e8 100644
--- a/arch/arm64/kvm/at.c
+++ b/arch/arm64/kvm/at.c
@@ -414,6 +414,8 @@ static int setup_s1_walk(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 	wi->hd &= (wi->regime == TR_EL2 ?
 		  FIELD_GET(TCR_EL2_HD, tcr) :
 		  FIELD_GET(TCR_HD, tcr));
+	wi->haft  = kvm_has_feat(vcpu->kvm, ID_AA64MMFR1_EL1, HAFDBS, HAFT) && wi->ha &&
+		    FIELD_GET(TCR2_EL1_HAFT, effective_tcr2(vcpu, wi->regime));
 
 	return 0;
 
@@ -463,7 +465,7 @@ static bool should_set_access_flag(struct s1_walk_info *wi, struct s1_walk_step
 	if (access->type == WALK_ACCESS_NONARCH)
 		return false;
 
-	return wi->ha;
+	return kvm_pte_table(ws->desc, ws->level) ? wi->haft : wi->ha;
 }
 
 static bool should_set_dirty_state(struct s1_walk_info *wi, struct s1_walk_step *ws,
@@ -471,6 +473,9 @@ static bool should_set_dirty_state(struct s1_walk_info *wi, struct s1_walk_step
 {
 	bool perm = wi->as_el0 ? wr->uw : wr->pw;
 
+	if (kvm_pte_table(ws->desc, ws->level))
+		return false;
+
 	switch (access->type) {
 	/* R_RKMHW */
 	case WALK_ACCESS_CMO:
@@ -621,6 +626,16 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 		if (ws.level == 3)
 			break;
 
+		baddr = desc_to_oa(wi, ws.desc);
+
+		/* Check for out-of-range OA */
+		if (check_output_size(baddr, wi))
+			goto addrsz;
+
+		ret = handle_desc_update(vcpu, wi, &ws, wr, access);
+		if (ret)
+			return ret;
+
 		/* Table handling */
 		if (!wi->hpd) {
 			wr->APTable  |= FIELD_GET(S1_TABLE_AP, ws.desc);
@@ -628,12 +643,6 @@ static int walk_s1(struct kvm_vcpu *vcpu, struct s1_walk_info *wi,
 			wr->PXNTable |= FIELD_GET(PMD_TABLE_PXN, ws.desc);
 		}
 
-		baddr = desc_to_oa(wi, ws.desc);
-
-		/* Check for out-of-range OA */
-		if (check_output_size(baddr, wi))
-			goto addrsz;
-
 		/* Prepare for next round */
 		va_top = va_bottom - 1;
 		ws.level++;
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 9c83837b184d..fc22dc70f167 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -72,17 +72,6 @@ static u32 kvm_pgd_pages(u32 ia_bits, s8 start_level)
 	return kvm_pgd_page_idx(&pgt, -1ULL) + 1;
 }
 
-static bool kvm_pte_table(kvm_pte_t pte, s8 level)
-{
-	if (level == KVM_PGTABLE_LAST_LEVEL)
-		return false;
-
-	if (!kvm_pte_valid(pte))
-		return false;
-
-	return FIELD_GET(KVM_PTE_TYPE, pte) == KVM_PTE_TYPE_TABLE;
-}
-
 static kvm_pte_t *kvm_pte_follow(kvm_pte_t pte, struct kvm_pgtable_mm_ops *mm_ops)
 {
 	return mm_ops->phys_to_virt(kvm_pte_to_phys(pte));
-- 
2.47.3