xref: /linux/arch/arm64/kvm/sys_regs.h (revision ca853314e78b0a65c20b6a889a23c31f918d4aa2)
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 };
23 
24 struct sys_reg_desc {
25 	/* Sysreg string for debug */
26 	const char *name;
27 
28 	enum {
29 		AA32_ZEROHIGH,
30 		AA32_LO,
31 		AA32_HI,
32 	} aarch32_map;
33 
34 	/* MRS/MSR instruction which accesses it. */
35 	u8	Op0;
36 	u8	Op1;
37 	u8	CRn;
38 	u8	CRm;
39 	u8	Op2;
40 
41 	/* Trapped access from guest, if non-NULL. */
42 	bool (*access)(struct kvm_vcpu *,
43 		       struct sys_reg_params *,
44 		       const struct sys_reg_desc *);
45 
46 	/* Initialization for vcpu. */
47 	void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
48 
49 	/* Index into sys_reg[], or 0 if we don't need to save it. */
50 	int reg;
51 
52 	/* Value (usually reset value) */
53 	u64 val;
54 
55 	/* Custom get/set_user functions, fallback to generic if NULL */
56 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
57 			const struct kvm_one_reg *reg, void __user *uaddr);
58 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
59 			const struct kvm_one_reg *reg, void __user *uaddr);
60 
61 	/* Return mask of REG_* runtime visibility overrides */
62 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
63 				   const struct sys_reg_desc *rd);
64 };
65 
66 #define REG_HIDDEN		(1 << 0) /* hidden from userspace and guest */
67 #define REG_RAZ			(1 << 1) /* RAZ from userspace and guest */
68 
69 static __printf(2, 3)
70 inline void print_sys_reg_msg(const struct sys_reg_params *p,
71 				       char *fmt, ...)
72 {
73 	va_list va;
74 
75 	va_start(va, fmt);
76 	/* Look, we even formatted it for you to paste into the table! */
77 	kvm_pr_unimpl("%pV { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
78 		      &(struct va_format){ fmt, &va },
79 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
80 	va_end(va);
81 }
82 
83 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
84 {
85 	/* GCC warns on an empty format string */
86 	print_sys_reg_msg(p, "%s", "");
87 }
88 
89 static inline bool ignore_write(struct kvm_vcpu *vcpu,
90 				const struct sys_reg_params *p)
91 {
92 	return true;
93 }
94 
95 static inline bool read_zero(struct kvm_vcpu *vcpu,
96 			     struct sys_reg_params *p)
97 {
98 	p->regval = 0;
99 	return true;
100 }
101 
102 /* Reset functions */
103 static inline void reset_unknown(struct kvm_vcpu *vcpu,
104 				 const struct sys_reg_desc *r)
105 {
106 	BUG_ON(!r->reg);
107 	BUG_ON(r->reg >= NR_SYS_REGS);
108 	__vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
109 }
110 
111 static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
112 {
113 	BUG_ON(!r->reg);
114 	BUG_ON(r->reg >= NR_SYS_REGS);
115 	__vcpu_sys_reg(vcpu, r->reg) = r->val;
116 }
117 
118 static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu,
119 				 const struct sys_reg_desc *r)
120 {
121 	if (likely(!r->visibility))
122 		return false;
123 
124 	return r->visibility(vcpu, r) & REG_HIDDEN;
125 }
126 
127 static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu,
128 					 const struct sys_reg_desc *r)
129 {
130 	if (likely(!r->visibility))
131 		return false;
132 
133 	return r->visibility(vcpu, r) & REG_RAZ;
134 }
135 
136 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
137 			      const struct sys_reg_desc *i2)
138 {
139 	BUG_ON(i1 == i2);
140 	if (!i1)
141 		return 1;
142 	else if (!i2)
143 		return -1;
144 	if (i1->Op0 != i2->Op0)
145 		return i1->Op0 - i2->Op0;
146 	if (i1->Op1 != i2->Op1)
147 		return i1->Op1 - i2->Op1;
148 	if (i1->CRn != i2->CRn)
149 		return i1->CRn - i2->CRn;
150 	if (i1->CRm != i2->CRm)
151 		return i1->CRm - i2->CRm;
152 	return i1->Op2 - i2->Op2;
153 }
154 
155 const struct sys_reg_desc *find_reg_by_id(u64 id,
156 					  struct sys_reg_params *params,
157 					  const struct sys_reg_desc table[],
158 					  unsigned int num);
159 
160 #define AA32(_x)	.aarch32_map = AA32_##_x
161 #define Op0(_x) 	.Op0 = _x
162 #define Op1(_x) 	.Op1 = _x
163 #define CRn(_x)		.CRn = _x
164 #define CRm(_x) 	.CRm = _x
165 #define Op2(_x) 	.Op2 = _x
166 
167 #define SYS_DESC(reg)					\
168 	.name = #reg,					\
169 	Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),	\
170 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
171 	Op2(sys_reg_Op2(reg))
172 
173 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
174