[PATCH v4 6/7] KVM: arm64: Update age handlers to support PUD hugepages

[Punit Agrawal]

In preparation for creating larger hugepages at Stage 2, add support
to the age handling notifiers for PUD hugepages when encountered.

Provide trivial helpers for arm32 to allow sharing code.

Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
Cc: Christoffer Dall <christoffer.dall@xxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
---
 arch/arm/include/asm/kvm_mmu.h   |  6 ++++++
 arch/arm64/include/asm/kvm_mmu.h |  5 +++++
 arch/arm64/include/asm/pgtable.h |  1 +
 virt/kvm/arm/mmu.c               | 29 +++++++++++++++++++++++++----
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index a4298d429efc..8e1e8aee229e 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -110,6 +110,12 @@ static inline pud_t kvm_s2pud_mkyoung(pud_t pud)
 	return pud;
 }
 
+static inline bool kvm_s2pud_young(pud_t pud)
+{
+	BUG();
+	return false;
+}
+
 static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd)
 {
 	*pmd = new_pmd;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 4d2780c588b0..c542052fb199 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -261,6 +261,11 @@ static inline pud_t kvm_s2pud_mkyoung(pud_t pud)
 	return pud_mkyoung(pud);
 }
 
+static inline bool kvm_s2pud_young(pud_t pud)
+{
+	return pud_young(pud);
+}
+
 static inline bool kvm_page_empty(void *ptr)
 {
 	struct page *ptr_page = virt_to_page(ptr);
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index a64a5c35beb1..4d9476e420d9 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -385,6 +385,7 @@ static inline int pmd_protnone(pmd_t pmd)
 #define pfn_pmd(pfn,prot)	__pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
 #define mk_pmd(page,prot)	pfn_pmd(page_to_pfn(page),prot)
 
+#define pud_young(pud)		pte_young(pud_pte(pud))
 #define pud_mkyoung(pud)	pte_pud(pte_mkyoung(pud_pte(pud)))
 #define pud_write(pud)		pte_write(pud_pte(pud))
 
diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
index 94a91bcdd152..0c04c64e858c 100644
--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -1141,6 +1141,11 @@ static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
 	return stage2_ptep_test_and_clear_young((pte_t *)pmd);
 }
 
+static int stage2_pudp_test_and_clear_young(pud_t *pud)
+{
+	return stage2_ptep_test_and_clear_young((pte_t *)pud);
+}
+
 /**
  * kvm_phys_addr_ioremap - map a device range to guest IPA
  *
@@ -1860,11 +1865,19 @@ void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
 
 static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
 {
+	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 
-	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
-	pmd = stage2_get_pmd(kvm, NULL, gpa);
+	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
+	pud = stage2_get_pud(kvm, NULL, gpa);
+	if (!pud || pud_none(*pud))	/* Nothing there */
+		return 0;
+
+	if (pud_huge(*pud))		/* HugeTLB */
+		return stage2_pudp_test_and_clear_young(pud);
+
+	pmd = stage2_pmd_offset(pud, gpa);
 	if (!pmd || pmd_none(*pmd))	/* Nothing there */
 		return 0;
 
@@ -1880,11 +1893,19 @@ static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
 
 static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
 {
+	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte;
 
-	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
-	pmd = stage2_get_pmd(kvm, NULL, gpa);
+	WARN_ON(size != PAGE_SIZE && size != PMD_SIZE && size != PUD_SIZE);
+	pud = stage2_get_pud(kvm, NULL, gpa);
+	if (!pud || pud_none(*pud))	/* Nothing there */
+		return 0;
+
+	if (pud_huge(*pud))		/* HugeTLB */
+		return kvm_s2pud_young(*pud);
+
+	pmd = stage2_pmd_offset(pud, gpa);
 	if (!pmd || pmd_none(*pmd))	/* Nothing there */
 		return 0;
 
-- 
2.17.1