kvm_mmu.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
  4 */
  5
  6#ifndef __ASM_LOONGARCH_KVM_MMU_H__
  7#define __ASM_LOONGARCH_KVM_MMU_H__
  8
  9#include <linux/kvm_host.h>
 10#include <asm/pgalloc.h>
 11#include <asm/tlb.h>
 12
 13/*
 14 * KVM_MMU_CACHE_MIN_PAGES is the number of GPA page table translation levels
 15 * for which pages need to be cached.
 16 */
 17#define KVM_MMU_CACHE_MIN_PAGES	(CONFIG_PGTABLE_LEVELS - 1)
 18
 19/*
 20 * _PAGE_MODIFIED is a SW pte bit, it records page ever written on host
 21 * kernel, on secondary MMU it records the page writeable attribute, in
 22 * order for fast path handling.
 23 */
 24#define KVM_PAGE_WRITEABLE	_PAGE_MODIFIED
 25
 26#define _KVM_FLUSH_PGTABLE	0x1
 27#define _KVM_HAS_PGMASK		0x2
 28#define kvm_pfn_pte(pfn, prot)	(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
 29#define kvm_pte_pfn(x)		((phys_addr_t)((x & _PFN_MASK) >> PFN_PTE_SHIFT))
 30
 31typedef unsigned long kvm_pte_t;
 32typedef struct kvm_ptw_ctx kvm_ptw_ctx;
 33typedef int (*kvm_pte_ops)(kvm_pte_t *pte, phys_addr_t addr, kvm_ptw_ctx *ctx);
 34
 35struct kvm_ptw_ctx {
 36	kvm_pte_ops     ops;
 37	unsigned long   flag;
 38
 39	/* for kvm_arch_mmu_enable_log_dirty_pt_masked use */
 40	unsigned long   mask;
 41	unsigned long   gfn;
 42
 43	/* page walk mmu info */
 44	unsigned int    level;
 45	unsigned long   pgtable_shift;
 46	unsigned long   invalid_entry;
 47	unsigned long   *invalid_ptes;
 48	unsigned int    *pte_shifts;
 49	void		*opaque;
 50
 51	/* free pte table page list */
 52	struct list_head list;
 53};
 54
 55kvm_pte_t *kvm_pgd_alloc(void);
 56
 57static inline void kvm_set_pte(kvm_pte_t *ptep, kvm_pte_t val)
 58{
 59	WRITE_ONCE(*ptep, val);
 60}
 61
 62static inline int kvm_pte_young(kvm_pte_t pte) { return pte & _PAGE_ACCESSED; }
 63static inline int kvm_pte_huge(kvm_pte_t pte) { return pte & _PAGE_HUGE; }
 64static inline int kvm_pte_dirty(kvm_pte_t pte) { return pte & __WRITEABLE; }
 65static inline int kvm_pte_writeable(kvm_pte_t pte) { return pte & KVM_PAGE_WRITEABLE; }
 66
 67static inline kvm_pte_t kvm_pte_mkyoung(kvm_pte_t pte)
 68{
 69	return pte | _PAGE_ACCESSED;
 70}
 71
 72static inline kvm_pte_t kvm_pte_mkold(kvm_pte_t pte)
 73{
 74	return pte & ~_PAGE_ACCESSED;
 75}
 76
 77static inline kvm_pte_t kvm_pte_mkdirty(kvm_pte_t pte)
 78{
 79	return pte | __WRITEABLE;
 80}
 81
 82static inline kvm_pte_t kvm_pte_mkclean(kvm_pte_t pte)
 83{
 84	return pte & ~__WRITEABLE;
 85}
 86
 87static inline kvm_pte_t kvm_pte_mkhuge(kvm_pte_t pte)
 88{
 89	return pte | _PAGE_HUGE;
 90}
 91
 92static inline kvm_pte_t kvm_pte_mksmall(kvm_pte_t pte)
 93{
 94	return pte & ~_PAGE_HUGE;
 95}
 96
 97static inline kvm_pte_t kvm_pte_mkwriteable(kvm_pte_t pte)
 98{
 99	return pte | KVM_PAGE_WRITEABLE;
100}
101
102static inline int kvm_need_flush(kvm_ptw_ctx *ctx)
103{
104	return ctx->flag & _KVM_FLUSH_PGTABLE;
105}
106
107static inline kvm_pte_t *kvm_pgtable_offset(kvm_ptw_ctx *ctx, kvm_pte_t *table,
108					phys_addr_t addr)
109{
110
111	return table + ((addr >> ctx->pgtable_shift) & (PTRS_PER_PTE - 1));
112}
113
114static inline phys_addr_t kvm_pgtable_addr_end(kvm_ptw_ctx *ctx,
115				phys_addr_t addr, phys_addr_t end)
116{
117	phys_addr_t boundary, size;
118
119	size = 0x1UL << ctx->pgtable_shift;
120	boundary = (addr + size) & ~(size - 1);
121	return (boundary - 1 < end - 1) ? boundary : end;
122}
123
124static inline int kvm_pte_present(kvm_ptw_ctx *ctx, kvm_pte_t *entry)
125{
126	if (!ctx || ctx->level == 0)
127		return !!(*entry & _PAGE_PRESENT);
128
129	return *entry != ctx->invalid_entry;
130}
131
132static inline int kvm_pte_none(kvm_ptw_ctx *ctx, kvm_pte_t *entry)
133{
134	return *entry == ctx->invalid_entry;
135}
136
137static inline void kvm_ptw_enter(kvm_ptw_ctx *ctx)
138{
139	ctx->level--;
140	ctx->pgtable_shift = ctx->pte_shifts[ctx->level];
141	ctx->invalid_entry = ctx->invalid_ptes[ctx->level];
142}
143
144static inline void kvm_ptw_exit(kvm_ptw_ctx *ctx)
145{
146	ctx->level++;
147	ctx->pgtable_shift = ctx->pte_shifts[ctx->level];
148	ctx->invalid_entry = ctx->invalid_ptes[ctx->level];
149}
150
151#endif /* __ASM_LOONGARCH_KVM_MMU_H__ */