xref: /linux/arch/arm64/kvm/sys_regs.h (revision 9a6b55ac)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012,2013 - ARM Ltd
4  * Author: Marc Zyngier <marc.zyngier@arm.com>
5  *
6  * Derived from arch/arm/kvm/coproc.h
7  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
8  * Authors: Christoffer Dall <c.dall@virtualopensystems.com>
9  */
10 
11 #ifndef __ARM64_KVM_SYS_REGS_LOCAL_H__
12 #define __ARM64_KVM_SYS_REGS_LOCAL_H__
13 
14 struct sys_reg_params {
15 	u8	Op0;
16 	u8	Op1;
17 	u8	CRn;
18 	u8	CRm;
19 	u8	Op2;
20 	u64	regval;
21 	bool	is_write;
22 	bool	is_aarch32;
23 	bool	is_32bit;	/* Only valid if is_aarch32 is true */
24 };
25 
26 struct sys_reg_desc {
27 	/* Sysreg string for debug */
28 	const char *name;
29 
30 	/* MRS/MSR instruction which accesses it. */
31 	u8	Op0;
32 	u8	Op1;
33 	u8	CRn;
34 	u8	CRm;
35 	u8	Op2;
36 
37 	/* Trapped access from guest, if non-NULL. */
38 	bool (*access)(struct kvm_vcpu *,
39 		       struct sys_reg_params *,
40 		       const struct sys_reg_desc *);
41 
42 	/* Initialization for vcpu. */
43 	void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
44 
45 	/* Index into sys_reg[], or 0 if we don't need to save it. */
46 	int reg;
47 
48 	/* Value (usually reset value) */
49 	u64 val;
50 
51 	/* Custom get/set_user functions, fallback to generic if NULL */
52 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
53 			const struct kvm_one_reg *reg, void __user *uaddr);
54 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
55 			const struct kvm_one_reg *reg, void __user *uaddr);
56 
57 	/* Return mask of REG_* runtime visibility overrides */
58 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
59 				   const struct sys_reg_desc *rd);
60 };
61 
62 #define REG_HIDDEN_USER		(1 << 0) /* hidden from userspace ioctls */
63 #define REG_HIDDEN_GUEST	(1 << 1) /* hidden from guest */
64 
65 static __printf(2, 3)
66 inline void print_sys_reg_msg(const struct sys_reg_params *p,
67 				       char *fmt, ...)
68 {
69 	va_list va;
70 
71 	va_start(va, fmt);
72 	/* Look, we even formatted it for you to paste into the table! */
73 	kvm_pr_unimpl("%pV { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
74 		      &(struct va_format){ fmt, &va },
75 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
76 	va_end(va);
77 }
78 
79 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
80 {
81 	/* GCC warns on an empty format string */
82 	print_sys_reg_msg(p, "%s", "");
83 }
84 
85 static inline bool ignore_write(struct kvm_vcpu *vcpu,
86 				const struct sys_reg_params *p)
87 {
88 	return true;
89 }
90 
91 static inline bool read_zero(struct kvm_vcpu *vcpu,
92 			     struct sys_reg_params *p)
93 {
94 	p->regval = 0;
95 	return true;
96 }
97 
98 /* Reset functions */
99 static inline void reset_unknown(struct kvm_vcpu *vcpu,
100 				 const struct sys_reg_desc *r)
101 {
102 	BUG_ON(!r->reg);
103 	BUG_ON(r->reg >= NR_SYS_REGS);
104 	__vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
105 }
106 
107 static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
108 {
109 	BUG_ON(!r->reg);
110 	BUG_ON(r->reg >= NR_SYS_REGS);
111 	__vcpu_sys_reg(vcpu, r->reg) = r->val;
112 }
113 
114 static inline bool sysreg_hidden_from_guest(const struct kvm_vcpu *vcpu,
115 					    const struct sys_reg_desc *r)
116 {
117 	if (likely(!r->visibility))
118 		return false;
119 
120 	return r->visibility(vcpu, r) & REG_HIDDEN_GUEST;
121 }
122 
123 static inline bool sysreg_hidden_from_user(const struct kvm_vcpu *vcpu,
124 					   const struct sys_reg_desc *r)
125 {
126 	if (likely(!r->visibility))
127 		return false;
128 
129 	return r->visibility(vcpu, r) & REG_HIDDEN_USER;
130 }
131 
132 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
133 			      const struct sys_reg_desc *i2)
134 {
135 	BUG_ON(i1 == i2);
136 	if (!i1)
137 		return 1;
138 	else if (!i2)
139 		return -1;
140 	if (i1->Op0 != i2->Op0)
141 		return i1->Op0 - i2->Op0;
142 	if (i1->Op1 != i2->Op1)
143 		return i1->Op1 - i2->Op1;
144 	if (i1->CRn != i2->CRn)
145 		return i1->CRn - i2->CRn;
146 	if (i1->CRm != i2->CRm)
147 		return i1->CRm - i2->CRm;
148 	return i1->Op2 - i2->Op2;
149 }
150 
151 const struct sys_reg_desc *find_reg_by_id(u64 id,
152 					  struct sys_reg_params *params,
153 					  const struct sys_reg_desc table[],
154 					  unsigned int num);
155 
156 #define Op0(_x) 	.Op0 = _x
157 #define Op1(_x) 	.Op1 = _x
158 #define CRn(_x)		.CRn = _x
159 #define CRm(_x) 	.CRm = _x
160 #define Op2(_x) 	.Op2 = _x
161 
162 #define SYS_DESC(reg)					\
163 	.name = #reg,					\
164 	Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),	\
165 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
166 	Op2(sys_reg_Op2(reg))
167 
168 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
169