[RFC PATCH 3/7] kvm: arm64: Add level_apply parameter for stage2_attr_walker

[Keqian Zhu]

In order to change PTEs of some specific levels, the level_apply
parameter can be used as a level mask.

This has no fuctional change for current code.

Signed-off-by: Keqian Zhu <zhukeqi...@huawei.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 4915ba35f93b..0f8a319f16fe 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -734,6 +734,7 @@ struct stage2_attr_data {
        kvm_pte_t       attr_clr;
        kvm_pte_t       pte;
        u32             level;
+       u32             level_apply;
 };
 
 static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
@@ -743,6 +744,9 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, 
kvm_pte_t *ptep,
        kvm_pte_t pte = *ptep;
        struct stage2_attr_data *data = arg;
 
+       if (!(data->level_apply & BIT(level)))
+               return 0;
+
        if (!kvm_pte_valid(pte))
                return 0;
 
@@ -753,14 +757,15 @@ 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,
-                                   u32 *level)
+                                   kvm_pte_t attr_clr, u32 level_apply,
+                                   kvm_pte_t *orig_pte, u32 *level)
 {
        int ret;
        kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI;
        struct stage2_attr_data data = {
                .attr_set       = attr_set & attr_mask,
                .attr_clr       = attr_clr & attr_mask,
+               .level_apply    = level_apply,
        };
        struct kvm_pgtable_walker walker = {
                .cb             = stage2_attr_walker,
@@ -783,7 +788,7 @@ static int stage2_update_leaf_attrs(struct kvm_pgtable 
*pgt, u64 addr,
 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,
+                                       KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, -1,
                                        NULL, NULL);
 }
 
@@ -791,7 +796,7 @@ 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, NULL);
+                                -1, &pte, NULL);
        dsb(ishst);
        return pte;
 }
@@ -800,7 +805,7 @@ 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, NULL);
+                                -1, &pte, NULL);
        /*
         * "But where's the TLBI?!", you scream.
         * "Over in the core code", I sigh.
@@ -813,7 +818,7 @@ 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, NULL);
+       stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, -1, &pte, NULL);
        return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF;
 }
 
@@ -833,7 +838,7 @@ 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, &level);
+       ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, -1, NULL, 
&level);
        if (!ret)
                kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level);
        return ret;
-- 
2.19.1