Prepare some basic functions to support hardware DBM for PTEs.
Signed-off-by: Keqian Zhu <zhukeqian1@xxxxxxxxxx>
Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_mmu.h | 36 ++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index b12bfc1f051a..e0ee6e23d626 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -265,6 +265,42 @@ static inline bool kvm_s2pud_young(pud_t pud)
return pud_young(pud);
}
+#ifdef CONFIG_ARM64_HW_AFDBM
+static inline bool kvm_hw_dbm_enabled(void)
+{
+ return !!(read_sysreg(vtcr_el2) & VTCR_EL2_HD);
+}
+
+static inline void kvm_set_s2pte_dbm(pte_t *ptep)
+{
+ pteval_t old_pteval, pteval;
+
+ pteval = READ_ONCE(pte_val(*ptep));
+ do {
+ old_pteval = pteval;
+ pteval |= PTE_DBM;
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
+ } while (pteval != old_pteval);
+}
+
+static inline void kvm_clear_s2pte_dbm(pte_t *ptep)
+{
+ pteval_t old_pteval, pteval;
+
+ pteval = READ_ONCE(pte_val(*ptep));
+ do {
+ old_pteval = pteval;
+ pteval &= ~PTE_DBM;
+ pteval = cmpxchg_relaxed(&pte_val(*ptep), old_pteval, pteval);
+ } while (pteval != old_pteval);
+}
+
+static inline bool kvm_s2pte_dbm(pte_t *ptep)
+{
+ return !!(READ_ONCE(pte_val(*ptep)) & PTE_DBM);
+}
+#endif /* CONFIG_ARM64_HW_AFDBM */
+
#define hyp_pte_table_empty(ptep) kvm_page_empty(ptep)
#ifdef __PAGETABLE_PMD_FOLDED
--
2.19.1
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