@@ -170,10 +170,9 @@ static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp)
smp_store_release(ptep, pte);
}
-static bool kvm_set_valid_leaf_pte(kvm_pte_t *ptep, u64 pa, kvm_pte_t attr,
- u32 level)
+static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, u32 level)
{
- kvm_pte_t old = *ptep, pte = kvm_phys_to_pte(pa);
+ kvm_pte_t pte = kvm_phys_to_pte(pa);
u64 type = (level == KVM_PGTABLE_MAX_LEVELS - 1) ? KVM_PTE_TYPE_PAGE :
KVM_PTE_TYPE_BLOCK;
@@ -181,12 +180,7 @@ static bool kvm_set_valid_leaf_pte(kvm_pte_t *ptep, u64 pa, kvm_pte_t attr,
pte |= FIELD_PREP(KVM_PTE_TYPE, type);
pte |= KVM_PTE_VALID;
- /* Tolerate KVM recreating the exact same mapping. */
- if (kvm_pte_valid(old))
- return old == pte;
-
- smp_store_release(ptep, pte);
- return true;
+ return pte;
}
static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, u64 addr,
@@ -341,12 +335,17 @@ static int hyp_map_set_prot_attr(enum kvm_pgtable_prot prot,
static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
kvm_pte_t *ptep, struct hyp_map_data *data)
{
+ kvm_pte_t new, old = *ptep;
u64 granule = kvm_granule_size(level), phys = data->phys;
if (!kvm_block_mapping_supported(addr, end, phys, level))
return false;
- WARN_ON(!kvm_set_valid_leaf_pte(ptep, phys, data->attr, level));
+ /* Tolerate KVM recreating the exact same mapping */
+ new = kvm_init_valid_leaf_pte(phys, data->attr, level);
+ if (old != new && !WARN_ON(kvm_pte_valid(old)))
+ smp_store_release(ptep, new);
+
data->phys += granule;
return true;
}
@@ -465,27 +464,29 @@ static bool stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level,
kvm_pte_t *ptep,
struct stage2_map_data *data)
{
+ kvm_pte_t new, old = *ptep;
u64 granule = kvm_granule_size(level), phys = data->phys;
if (!kvm_block_mapping_supported(addr, end, phys, level))
return false;
- /*
- * If the PTE was already valid, drop the refcount on the table
- * early, as it will be bumped-up again in stage2_map_walk_leaf().
- * This ensures that the refcount stays constant across a valid to
- * valid PTE update.
- */
- if (kvm_pte_valid(*ptep))
- put_page(virt_to_page(ptep));
+ new = kvm_init_valid_leaf_pte(phys, data->attr, level);
+ if (kvm_pte_valid(old)) {
+ /* Tolerate KVM recreating the exact same mapping */
+ if (old == new)
+ goto out;
- if (kvm_set_valid_leaf_pte(ptep, phys, data->attr, level))
- goto out;
+ /*
+ * There's an existing different valid leaf entry, so perform
+ * break-before-make.
+ */
+ kvm_set_invalid_pte(ptep);
+ kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level);
+ put_page(virt_to_page(ptep));
+ }
- /* There's an existing valid leaf entry, so perform break-before-make */
- kvm_set_invalid_pte(ptep);
- kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, data->mmu, addr, level);
- kvm_set_valid_leaf_pte(ptep, phys, data->attr, level);
+ smp_store_release(ptep, new);
+ get_page(virt_to_page(ptep));
out:
data->phys += granule;
return true;
@@ -527,7 +528,7 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
}
if (stage2_map_walker_try_leaf(addr, end, level, ptep, data))
- goto out_get_page;
+ return 0;
if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1))
return -EINVAL;
@@ -551,9 +552,8 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
}
kvm_set_table_pte(ptep, childp);
-
-out_get_page:
get_page(page);
+
return 0;
}
Procedures of hyp stage-1 map and guest stage-2 map are quite different, but they are tied closely by function kvm_set_valid_leaf_pte(). So adjust the relative code for ease of code maintenance in the future. Signed-off-by: Yanan Wang <wangyanan55@huawei.com> --- arch/arm64/kvm/hyp/pgtable.c | 54 ++++++++++++++++++------------------ 1 file changed, 27 insertions(+), 27 deletions(-)