xref: /linux/arch/x86/kvm/mmu.h (revision 2a2c74b2efcb1a0ca3fdcb5fbb96ad8de6a29177)
1 #ifndef __KVM_X86_MMU_H
2 #define __KVM_X86_MMU_H
3 
4 #include <linux/kvm_host.h>
5 #include "kvm_cache_regs.h"
6 
7 #define PT64_PT_BITS 9
8 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS)
9 #define PT32_PT_BITS 10
10 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS)
11 
12 #define PT_WRITABLE_SHIFT 1
13 
14 #define PT_PRESENT_MASK (1ULL << 0)
15 #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT)
16 #define PT_USER_MASK (1ULL << 2)
17 #define PT_PWT_MASK (1ULL << 3)
18 #define PT_PCD_MASK (1ULL << 4)
19 #define PT_ACCESSED_SHIFT 5
20 #define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT)
21 #define PT_DIRTY_SHIFT 6
22 #define PT_DIRTY_MASK (1ULL << PT_DIRTY_SHIFT)
23 #define PT_PAGE_SIZE_SHIFT 7
24 #define PT_PAGE_SIZE_MASK (1ULL << PT_PAGE_SIZE_SHIFT)
25 #define PT_PAT_MASK (1ULL << 7)
26 #define PT_GLOBAL_MASK (1ULL << 8)
27 #define PT64_NX_SHIFT 63
28 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT)
29 
30 #define PT_PAT_SHIFT 7
31 #define PT_DIR_PAT_SHIFT 12
32 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT)
33 
34 #define PT32_DIR_PSE36_SIZE 4
35 #define PT32_DIR_PSE36_SHIFT 13
36 #define PT32_DIR_PSE36_MASK \
37 	(((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT)
38 
39 #define PT64_ROOT_LEVEL 4
40 #define PT32_ROOT_LEVEL 2
41 #define PT32E_ROOT_LEVEL 3
42 
43 #define PT_PDPE_LEVEL 3
44 #define PT_DIRECTORY_LEVEL 2
45 #define PT_PAGE_TABLE_LEVEL 1
46 
47 #define PFERR_PRESENT_BIT 0
48 #define PFERR_WRITE_BIT 1
49 #define PFERR_USER_BIT 2
50 #define PFERR_RSVD_BIT 3
51 #define PFERR_FETCH_BIT 4
52 
53 #define PFERR_PRESENT_MASK (1U << PFERR_PRESENT_BIT)
54 #define PFERR_WRITE_MASK (1U << PFERR_WRITE_BIT)
55 #define PFERR_USER_MASK (1U << PFERR_USER_BIT)
56 #define PFERR_RSVD_MASK (1U << PFERR_RSVD_BIT)
57 #define PFERR_FETCH_MASK (1U << PFERR_FETCH_BIT)
58 
59 int kvm_mmu_get_spte_hierarchy(struct kvm_vcpu *vcpu, u64 addr, u64 sptes[4]);
60 void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask);
61 
62 /*
63  * Return values of handle_mmio_page_fault_common:
64  * RET_MMIO_PF_EMULATE: it is a real mmio page fault, emulate the instruction
65  *			directly.
66  * RET_MMIO_PF_INVALID: invalid spte is detected then let the real page
67  *			fault path update the mmio spte.
68  * RET_MMIO_PF_RETRY: let CPU fault again on the address.
69  * RET_MMIO_PF_BUG: bug is detected.
70  */
71 enum {
72 	RET_MMIO_PF_EMULATE = 1,
73 	RET_MMIO_PF_INVALID = 2,
74 	RET_MMIO_PF_RETRY = 0,
75 	RET_MMIO_PF_BUG = -1
76 };
77 
78 int handle_mmio_page_fault_common(struct kvm_vcpu *vcpu, u64 addr, bool direct);
79 void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
80 void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, struct kvm_mmu *context,
81 		bool execonly);
82 void update_permission_bitmask(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
83 		bool ept);
84 
85 static inline unsigned int kvm_mmu_available_pages(struct kvm *kvm)
86 {
87 	if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages)
88 		return kvm->arch.n_max_mmu_pages -
89 			kvm->arch.n_used_mmu_pages;
90 
91 	return 0;
92 }
93 
94 static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu)
95 {
96 	if (likely(vcpu->arch.mmu.root_hpa != INVALID_PAGE))
97 		return 0;
98 
99 	return kvm_mmu_load(vcpu);
100 }
101 
102 static inline int is_present_gpte(unsigned long pte)
103 {
104 	return pte & PT_PRESENT_MASK;
105 }
106 
107 static inline int is_writable_pte(unsigned long pte)
108 {
109 	return pte & PT_WRITABLE_MASK;
110 }
111 
112 static inline bool is_write_protection(struct kvm_vcpu *vcpu)
113 {
114 	return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
115 }
116 
117 /*
118  * Will a fault with a given page-fault error code (pfec) cause a permission
119  * fault with the given access (in ACC_* format)?
120  */
121 static inline bool permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
122 				    unsigned pte_access, unsigned pfec)
123 {
124 	int cpl = kvm_x86_ops->get_cpl(vcpu);
125 	unsigned long rflags = kvm_x86_ops->get_rflags(vcpu);
126 
127 	/*
128 	 * If CPL < 3, SMAP prevention are disabled if EFLAGS.AC = 1.
129 	 *
130 	 * If CPL = 3, SMAP applies to all supervisor-mode data accesses
131 	 * (these are implicit supervisor accesses) regardless of the value
132 	 * of EFLAGS.AC.
133 	 *
134 	 * This computes (cpl < 3) && (rflags & X86_EFLAGS_AC), leaving
135 	 * the result in X86_EFLAGS_AC. We then insert it in place of
136 	 * the PFERR_RSVD_MASK bit; this bit will always be zero in pfec,
137 	 * but it will be one in index if SMAP checks are being overridden.
138 	 * It is important to keep this branchless.
139 	 */
140 	unsigned long smap = (cpl - 3) & (rflags & X86_EFLAGS_AC);
141 	int index = (pfec >> 1) +
142 		    (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1));
143 
144 	return (mmu->permissions[index] >> pte_access) & 1;
145 }
146 
147 void kvm_mmu_invalidate_zap_all_pages(struct kvm *kvm);
148 #endif
149