x86/paravirt: Add 5-level support to the paravirt code

Add operations to allocate/release p4ds.

Xen requires more work. We will need to come back to it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170330080731.65421-5-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/paravirt.h

@@ -357,6 +357,16 @@ static inline void paravirt_release_pud(unsigned long pfn)
 	PVOP_VCALL1(pv_mmu_ops.release_pud, pfn);
 }
 
+static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn)
+{
+	PVOP_VCALL2(pv_mmu_ops.alloc_p4d, mm, pfn);
+}
+
+static inline void paravirt_release_p4d(unsigned long pfn)
+{
+	PVOP_VCALL1(pv_mmu_ops.release_p4d, pfn);
+}
+
 static inline void pte_update(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep)
 {
@@ -582,25 +592,25 @@ static inline void set_p4d(p4d_t *p4dp, p4d_t p4d)
 			    val);
 }
 
-static inline void p4d_clear(p4d_t *p4dp)
+#if CONFIG_PGTABLE_LEVELS >= 5
+
+static inline p4d_t __p4d(p4dval_t val)
 {
-	set_p4d(p4dp, __p4d(0));
-}
+	p4dval_t ret = PVOP_CALLEE1(p4dval_t, pv_mmu_ops.make_p4d, val);
 
-#if CONFIG_PGTABLE_LEVELS >= 5
+	return (p4d_t) { ret };
+}
 
-#error FIXME
+static inline p4dval_t p4d_val(p4d_t p4d)
+{
+	return PVOP_CALLEE1(p4dval_t, pv_mmu_ops.p4d_val, p4d.p4d);
+}
 
 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
 {
 	pgdval_t val = native_pgd_val(pgd);
 
-	if (sizeof(pgdval_t) > sizeof(long))
-		PVOP_VCALL3(pv_mmu_ops.set_pgd, pgdp,
-			    val, (u64)val >> 32);
-	else
-		PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp,
-			    val);
+	PVOP_VCALL2(pv_mmu_ops.set_pgd, pgdp, val);
 }
 
 static inline void pgd_clear(pgd_t *pgdp)
@@ -610,6 +620,11 @@ static inline void pgd_clear(pgd_t *pgdp)
 
 #endif  /* CONFIG_PGTABLE_LEVELS == 5 */
 
+static inline void p4d_clear(p4d_t *p4dp)
+{
+	set_p4d(p4dp, __p4d(0));
+}
+
 #endif	/* CONFIG_PGTABLE_LEVELS == 4 */
 
 #endif	/* CONFIG_PGTABLE_LEVELS >= 3 */

arch/x86/include/asm/paravirt_types.h

@@ -238,9 +238,11 @@ struct pv_mmu_ops {
 	void (*alloc_pte)(struct mm_struct *mm, unsigned long pfn);
 	void (*alloc_pmd)(struct mm_struct *mm, unsigned long pfn);
 	void (*alloc_pud)(struct mm_struct *mm, unsigned long pfn);
+	void (*alloc_p4d)(struct mm_struct *mm, unsigned long pfn);
 	void (*release_pte)(unsigned long pfn);
 	void (*release_pmd)(unsigned long pfn);
 	void (*release_pud)(unsigned long pfn);
+	void (*release_p4d)(unsigned long pfn);
 
 	/* Pagetable manipulation functions */
 	void (*set_pte)(pte_t *ptep, pte_t pteval);
@@ -286,7 +288,10 @@ struct pv_mmu_ops {
 	void (*set_p4d)(p4d_t *p4dp, p4d_t p4dval);
 
 #if CONFIG_PGTABLE_LEVELS >= 5
-#error FIXME
+	struct paravirt_callee_save p4d_val;
+	struct paravirt_callee_save make_p4d;
+
+	void (*set_pgd)(pgd_t *pgdp, pgd_t pgdval);
 #endif	/* CONFIG_PGTABLE_LEVELS >= 5 */
 
 #endif	/* CONFIG_PGTABLE_LEVELS >= 4 */

arch/x86/include/asm/pgalloc.h

@@ -17,9 +17,11 @@ static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn)	{
 static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
 					    unsigned long start, unsigned long count) {}
 static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn)	{}
+static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn)	{}
 static inline void paravirt_release_pte(unsigned long pfn) {}
 static inline void paravirt_release_pmd(unsigned long pfn) {}
 static inline void paravirt_release_pud(unsigned long pfn) {}
+static inline void paravirt_release_p4d(unsigned long pfn) {}
 #endif
 
 /*

arch/x86/kernel/paravirt.c

@@ -405,9 +405,11 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
 	.alloc_pte = paravirt_nop,
 	.alloc_pmd = paravirt_nop,
 	.alloc_pud = paravirt_nop,
+	.alloc_p4d = paravirt_nop,
 	.release_pte = paravirt_nop,
 	.release_pmd = paravirt_nop,
 	.release_pud = paravirt_nop,
+	.release_p4d = paravirt_nop,
 
 	.set_pte = native_set_pte,
 	.set_pte_at = native_set_pte_at,
@@ -437,8 +439,11 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
 	.set_p4d = native_set_p4d,
 
 #if CONFIG_PGTABLE_LEVELS >= 5
-#error FIXME
-#endif /* CONFIG_PGTABLE_LEVELS >= 4 */
+	.p4d_val = PTE_IDENT,
+	.make_p4d = PTE_IDENT,
+
+	.set_pgd = native_set_pgd,
+#endif /* CONFIG_PGTABLE_LEVELS >= 5 */
 #endif /* CONFIG_PGTABLE_LEVELS >= 4 */
 #endif /* CONFIG_PGTABLE_LEVELS >= 3 */