x86: add pud_alloc for 4-level pagetables

Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/paravirt.c

@@ -369,8 +369,10 @@ struct pv_mmu_ops pv_mmu_ops = {
 	.alloc_pte = paravirt_nop,
 	.alloc_pmd = paravirt_nop,
 	.alloc_pmd_clone = paravirt_nop,
+	.alloc_pud = paravirt_nop,
 	.release_pte = paravirt_nop,
 	.release_pmd = paravirt_nop,
+	.release_pud = paravirt_nop,
 
 	.set_pte = native_set_pte,
 	.set_pte_at = native_set_pte_at,

arch/x86/mm/pgtable.c

@@ -38,6 +38,7 @@ void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd)
 #if PAGETABLE_LEVELS > 3
 void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud)
 {
+	paravirt_release_pud(__pa(pud) >> PAGE_SHIFT);
 	tlb_remove_page(tlb, virt_to_page(pud));
 }
 #endif	/* PAGETABLE_LEVELS > 3 */

include/asm-x86/paravirt.h

@@ -223,8 +223,10 @@ struct pv_mmu_ops {
 	void (*alloc_pte)(struct mm_struct *mm, u32 pfn);
 	void (*alloc_pmd)(struct mm_struct *mm, u32 pfn);
 	void (*alloc_pmd_clone)(u32 pfn, u32 clonepfn, u32 start, u32 count);
+	void (*alloc_pud)(struct mm_struct *mm, u32 pfn);
 	void (*release_pte)(u32 pfn);
 	void (*release_pmd)(u32 pfn);
+	void (*release_pud)(u32 pfn);
 
 	/* Pagetable manipulation functions */
 	void (*set_pte)(pte_t *ptep, pte_t pteval);
@@ -934,6 +936,15 @@ static inline void paravirt_release_pmd(unsigned pfn)
 	PVOP_VCALL1(pv_mmu_ops.release_pmd, pfn);
 }
 
+static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned pfn)
+{
+	PVOP_VCALL2(pv_mmu_ops.alloc_pud, mm, pfn);
+}
+static inline void paravirt_release_pud(unsigned pfn)
+{
+	PVOP_VCALL1(pv_mmu_ops.release_pud, pfn);
+}
+
 #ifdef CONFIG_HIGHPTE
 static inline void *kmap_atomic_pte(struct page *page, enum km_type type)
 {

include/asm-x86/pgalloc.h

@@ -11,8 +11,10 @@
 #define paravirt_alloc_pte(mm, pfn) do { } while (0)
 #define paravirt_alloc_pmd(mm, pfn) do { } while (0)
 #define paravirt_alloc_pmd_clone(pfn, clonepfn, start, count) do { } while (0)
+#define paravirt_alloc_pud(mm, pfn) do { } while (0)
 #define paravirt_release_pte(pfn) do { } while (0)
 #define paravirt_release_pmd(pfn) do { } while (0)
+#define paravirt_release_pud(pfn) do { } while (0)
 #endif
 
 /*
@@ -85,6 +87,7 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 #if PAGETABLE_LEVELS > 3
 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
 {
+	paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
 	set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pud)));
 }