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Subject[PATCH 03/16] KVM: arm64: Turn kvm_pgtable_stage2_set_owner into kvm_pgtable_stage2_annotate
Date
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 <maz@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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