kvm_pgtable_stage2_set_owner() could be generalised into a way
to store up to 63 bits in the page tables, as long as we don't
set bit 0.

Let's just do that.

Signed-off-by: Marc Zyngier <m...@kernel.org>
---
 arch/arm64/include/asm/kvm_pgtable.h  | 12 +++++++-----
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 14 ++++++++++++--
 arch/arm64/kvm/hyp/pgtable.c          | 20 ++++++--------------
 3 files changed, 25 insertions(+), 21 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_pgtable.h 
b/arch/arm64/include/asm/kvm_pgtable.h
index f004c0115d89..9579e8c2793b 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -274,14 +274,16 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 
addr, u64 size,
                           void *mc);
 
 /**
- * kvm_pgtable_stage2_set_owner() - Unmap and annotate pages in the IPA space 
to
- *                                 track ownership.
+ * kvm_pgtable_stage2_annotate() - Unmap and annotate pages in the IPA space
+ *                                to track ownership (and more).
  * @pgt:       Page-table structure initialised by kvm_pgtable_stage2_init*().
  * @addr:      Base intermediate physical address to annotate.
  * @size:      Size of the annotated range.
  * @mc:                Cache of pre-allocated and zeroed memory from which to 
allocate
  *             page-table pages.
- * @owner_id:  Unique identifier for the owner of the page.
+ * @annotation:        A 63 bit value that will be stored in the page tables.
+ *             @annotation[0] must be 0, and @annotation[63:1] is stored
+ *             in the page tables. @annotation as a whole must not be 0.
  *
  * By default, all page-tables are owned by identifier 0. This function can be
  * used to mark portions of the IPA space as owned by other entities. When a
@@ -290,8 +292,8 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 
addr, u64 size,
  *
  * Return: 0 on success, negative error code on failure.
  */
-int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
-                                void *mc, u8 owner_id);
+int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size,
+                               void *mc, kvm_pte_t annotation);
 
 /**
  * kvm_pgtable_stage2_unmap() - Remove a mapping from a guest stage-2 
page-table.
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c 
b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index d938ce95d3bd..ffe482c3b818 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -245,6 +245,15 @@ static int host_stage2_idmap(u64 addr)
        return ret;
 }
 
+#define KVM_INVALID_PTE_OWNER_MASK     GENMASK(63, 56)
+#define KVM_MAX_OWNER_ID               1
+
+static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id)
+{
+       BUG_ON(owner_id > KVM_MAX_OWNER_ID);
+       return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id);
+}
+
 int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end)
 {
        int ret;
@@ -257,8 +266,9 @@ int __pkvm_mark_hyp(phys_addr_t start, phys_addr_t end)
                return -EINVAL;
 
        hyp_spin_lock(&host_kvm.lock);
-       ret = kvm_pgtable_stage2_set_owner(&host_kvm.pgt, start, end - start,
-                                          &host_s2_pool, pkvm_hyp_id);
+       ret = kvm_pgtable_stage2_annotate(&host_kvm.pgt, start, end - start,
+                                         &host_s2_pool,
+                                         
kvm_init_invalid_leaf_owner(pkvm_hyp_id));
        hyp_spin_unlock(&host_kvm.lock);
 
        return ret != -EAGAIN ? ret : 0;
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index a5874ebd0354..a065f6d960af 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -50,9 +50,6 @@
 
 #define KVM_PTE_LEAF_ATTR_S2_IGNORED   GENMASK(58, 55)
 
-#define KVM_INVALID_PTE_OWNER_MASK     GENMASK(63, 56)
-#define KVM_MAX_OWNER_ID               1
-
 struct kvm_pgtable_walk_data {
        struct kvm_pgtable              *pgt;
        struct kvm_pgtable_walker       *walker;
@@ -206,11 +203,6 @@ static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t 
attr, u32 level)
        return pte;
 }
 
-static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id)
-{
-       return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id);
-}
-
 static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, u64 addr,
                                  u32 level, kvm_pte_t *ptep,
                                  enum kvm_pgtable_walk_flags flag)
@@ -466,7 +458,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
 struct stage2_map_data {
        u64                             phys;
        kvm_pte_t                       attr;
-       u8                              owner_id;
+       u64                             annotation;
 
        kvm_pte_t                       *anchor;
        kvm_pte_t                       *childp;
@@ -603,7 +595,7 @@ static int stage2_map_walker_try_leaf(u64 addr, u64 end, 
u32 level,
        if (kvm_phys_is_valid(phys))
                new = kvm_init_valid_leaf_pte(phys, data->attr, level);
        else
-               new = kvm_init_invalid_leaf_owner(data->owner_id);
+               new = data->annotation;
 
        if (stage2_pte_is_counted(old)) {
                /*
@@ -796,8 +788,8 @@ int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 
addr, u64 size,
        return ret;
 }
 
-int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
-                                void *mc, u8 owner_id)
+int kvm_pgtable_stage2_annotate(struct kvm_pgtable *pgt, u64 addr, u64 size,
+                               void *mc, kvm_pte_t annotation)
 {
        int ret;
        struct stage2_map_data map_data = {
@@ -805,7 +797,7 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, 
u64 addr, u64 size,
                .mmu            = pgt->mmu,
                .memcache       = mc,
                .mm_ops         = pgt->mm_ops,
-               .owner_id       = owner_id,
+               .annotation     = annotation,
        };
        struct kvm_pgtable_walker walker = {
                .cb             = stage2_map_walker,
@@ -815,7 +807,7 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, 
u64 addr, u64 size,
                .arg            = &map_data,
        };
 
-       if (owner_id > KVM_MAX_OWNER_ID)
+       if (!annotation || (annotation & PTE_VALID))
                return -EINVAL;
 
        ret = kvm_pgtable_walk(pgt, addr, size, &walker);
-- 
2.30.2

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