summaryrefslogtreecommitdiff
path: root/arch/x86/kvm/mmu/mmu_internal.h
blob: da6166b5c37704f5c254839f923f52048445766f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_MMU_INTERNAL_H
#define __KVM_X86_MMU_INTERNAL_H

#include <linux/types.h>
#include <linux/kvm_host.h>
#include <asm/kvm_host.h>

#undef MMU_DEBUG

#ifdef MMU_DEBUG
extern bool dbg;

#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
#define rmap_printk(fmt, args...) do { if (dbg) printk("%s: " fmt, __func__, ## args); } while (0)
#define MMU_WARN_ON(x) WARN_ON(x)
#else
#define pgprintk(x...) do { } while (0)
#define rmap_printk(x...) do { } while (0)
#define MMU_WARN_ON(x) do { } while (0)
#endif

/*
 * Unlike regular MMU roots, PAE "roots", a.k.a. PDPTEs/PDPTRs, have a PRESENT
 * bit, and thus are guaranteed to be non-zero when valid.  And, when a guest
 * PDPTR is !PRESENT, its corresponding PAE root cannot be set to INVALID_PAGE,
 * as the CPU would treat that as PRESENT PDPTR with reserved bits set.  Use
 * '0' instead of INVALID_PAGE to indicate an invalid PAE root.
 */
#define INVALID_PAE_ROOT	0
#define IS_VALID_PAE_ROOT(x)	(!!(x))

struct kvm_mmu_page {
	/*
	 * Note, "link" through "spt" fit in a single 64 byte cache line on
	 * 64-bit kernels, keep it that way unless there's a reason not to.
	 */
	struct list_head link;
	struct hlist_node hash_link;

	bool tdp_mmu_page;
	bool unsync;
	u8 mmu_valid_gen;
	bool lpage_disallowed; /* Can't be replaced by an equiv large page */

	/*
	 * The following two entries are used to key the shadow page in the
	 * hash table.
	 */
	union kvm_mmu_page_role role;
	gfn_t gfn;

	u64 *spt;
	/* hold the gfn of each spte inside spt */
	gfn_t *gfns;
	/* Currently serving as active root */
	union {
		int root_count;
		refcount_t tdp_mmu_root_count;
	};
	unsigned int unsync_children;
	struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */
	DECLARE_BITMAP(unsync_child_bitmap, 512);

	struct list_head lpage_disallowed_link;
#ifdef CONFIG_X86_32
	/*
	 * Used out of the mmu-lock to avoid reading spte values while an
	 * update is in progress; see the comments in __get_spte_lockless().
	 */
	int clear_spte_count;
#endif

	/* Number of writes since the last time traversal visited this page.  */
	atomic_t write_flooding_count;

#ifdef CONFIG_X86_64
	/* Used for freeing the page asynchronously if it is a TDP MMU page. */
	struct rcu_head rcu_head;
#endif
};

extern struct kmem_cache *mmu_page_header_cache;

static inline struct kvm_mmu_page *to_shadow_page(hpa_t shadow_page)
{
	struct page *page = pfn_to_page(shadow_page >> PAGE_SHIFT);

	return (struct kvm_mmu_page *)page_private(page);
}

static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep)
{
	return to_shadow_page(__pa(sptep));
}

static inline int kvm_mmu_role_as_id(union kvm_mmu_page_role role)
{
	return role.smm ? 1 : 0;
}

static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
{
	return kvm_mmu_role_as_id(sp->role);
}

static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
{
	/*
	 * When using the EPT page-modification log, the GPAs in the CPU dirty
	 * log would come from L2 rather than L1.  Therefore, we need to rely
	 * on write protection to record dirty pages, which bypasses PML, since
	 * writes now result in a vmexit.  Note, the check on CPU dirty logging
	 * being enabled is mandatory as the bits used to denote WP-only SPTEs
	 * are reserved for PAE paging (32-bit KVM).
	 */
	return kvm_x86_ops.cpu_dirty_log_size && sp->role.guest_mode;
}

int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,
			    gfn_t gfn, bool can_unsync, bool prefetch);

void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
				    struct kvm_memory_slot *slot, u64 gfn,
				    int min_level);
void kvm_flush_remote_tlbs_with_address(struct kvm *kvm,
					u64 start_gfn, u64 pages);
unsigned int pte_list_count(struct kvm_rmap_head *rmap_head);

/*
 * Return values of handle_mmio_page_fault, mmu.page_fault, and fast_page_fault().
 *
 * RET_PF_RETRY: let CPU fault again on the address.
 * RET_PF_EMULATE: mmio page fault, emulate the instruction directly.
 * RET_PF_INVALID: the spte is invalid, let the real page fault path update it.
 * RET_PF_FIXED: The faulting entry has been fixed.
 * RET_PF_SPURIOUS: The faulting entry was already fixed, e.g. by another vCPU.
 *
 * Any names added to this enum should be exported to userspace for use in
 * tracepoints via TRACE_DEFINE_ENUM() in mmutrace.h
 */
enum {
	RET_PF_RETRY = 0,
	RET_PF_EMULATE,
	RET_PF_INVALID,
	RET_PF_FIXED,
	RET_PF_SPURIOUS,
};

int kvm_mmu_max_mapping_level(struct kvm *kvm,
			      const struct kvm_memory_slot *slot, gfn_t gfn,
			      kvm_pfn_t pfn, int max_level);
void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level);

void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);

void account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp);
void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp);

#endif /* __KVM_X86_MMU_INTERNAL_H */