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

From: Punit Agrawal
Date: Thu Jul 05 2018 - 10:09:58 EST


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