xref: /linux/arch/arm64/kvm/sys_regs.h (revision d78a14decd494caf72ea0144624621e7e43ae451)
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 #include <linux/bsearch.h>
15 
16 #define reg_to_encoding(x)						\
17 	sys_reg((u32)(x)->Op0, (u32)(x)->Op1,				\
18 		(u32)(x)->CRn, (u32)(x)->CRm, (u32)(x)->Op2)
19 
20 struct sys_reg_params {
21 	u8	Op0;
22 	u8	Op1;
23 	u8	CRn;
24 	u8	CRm;
25 	u8	Op2;
26 	u64	regval;
27 	bool	is_write;
28 };
29 
30 #define encoding_to_params(reg)						\
31 	((struct sys_reg_params){ .Op0 = sys_reg_Op0(reg),		\
32 				  .Op1 = sys_reg_Op1(reg),		\
33 				  .CRn = sys_reg_CRn(reg),		\
34 				  .CRm = sys_reg_CRm(reg),		\
35 				  .Op2 = sys_reg_Op2(reg) })
36 
37 #define esr_sys64_to_params(esr)                                               \
38 	((struct sys_reg_params){ .Op0 = ((esr) >> 20) & 3,                    \
39 				  .Op1 = ((esr) >> 14) & 0x7,                  \
40 				  .CRn = ((esr) >> 10) & 0xf,                  \
41 				  .CRm = ((esr) >> 1) & 0xf,                   \
42 				  .Op2 = ((esr) >> 17) & 0x7,                  \
43 				  .is_write = !((esr) & 1) })
44 
45 #define esr_cp1x_32_to_params(esr)						\
46 	((struct sys_reg_params){ .Op1 = ((esr) >> 14) & 0x7,			\
47 				  .CRn = ((esr) >> 10) & 0xf,			\
48 				  .CRm = ((esr) >> 1) & 0xf,			\
49 				  .Op2 = ((esr) >> 17) & 0x7,			\
50 				  .is_write = !((esr) & 1) })
51 
52 /*
53  * The Feature ID space is defined as the System register space in AArch64
54  * with op0==3, op1=={0, 1, 3}, CRn==0, CRm=={0-7}, op2=={0-7}.
55  */
56 static inline bool in_feat_id_space(struct sys_reg_params *p)
57 {
58 	return (p->Op0 == 3 && !(p->Op1 & 0b100) && p->Op1 != 2 &&
59 		p->CRn == 0 && !(p->CRm & 0b1000));
60 }
61 
62 struct sys_reg_desc {
63 	/* Sysreg string for debug */
64 	const char *name;
65 
66 	enum {
67 		AA32_DIRECT,
68 		AA32_LO,
69 		AA32_HI,
70 	} aarch32_map;
71 
72 	/* MRS/MSR instruction which accesses it. */
73 	u8	Op0;
74 	u8	Op1;
75 	u8	CRn;
76 	u8	CRm;
77 	u8	Op2;
78 
79 	/* Trapped access from guest, if non-NULL. */
80 	bool (*access)(struct kvm_vcpu *,
81 		       struct sys_reg_params *,
82 		       const struct sys_reg_desc *);
83 
84 	/*
85 	 * Initialization for vcpu. Return initialized value, or KVM
86 	 * sanitized value for ID registers.
87 	 */
88 	u64 (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
89 
90 	/* Index into sys_reg[], or 0 if we don't need to save it. */
91 	int reg;
92 
93 	/* Value (usually reset value), or write mask for idregs */
94 	u64 val;
95 
96 	/* Custom get/set_user functions, fallback to generic if NULL */
97 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
98 			u64 *val);
99 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
100 			u64 val);
101 
102 	/* Return mask of REG_* runtime visibility overrides */
103 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
104 				   const struct sys_reg_desc *rd);
105 };
106 
107 #define REG_HIDDEN		(1 << 0) /* hidden from userspace and guest */
108 #define REG_RAZ			(1 << 1) /* RAZ from userspace and guest */
109 #define REG_USER_WI		(1 << 2) /* WI from userspace only */
110 
111 static __printf(2, 3)
112 inline void print_sys_reg_msg(const struct sys_reg_params *p,
113 				       char *fmt, ...)
114 {
115 	va_list va;
116 
117 	va_start(va, fmt);
118 	/* Look, we even formatted it for you to paste into the table! */
119 	kvm_pr_unimpl("%pV { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
120 		      &(struct va_format){ fmt, &va },
121 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, str_write_read(p->is_write));
122 	va_end(va);
123 }
124 
125 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
126 {
127 	/* GCC warns on an empty format string */
128 	print_sys_reg_msg(p, "%s", "");
129 }
130 
131 static inline bool ignore_write(struct kvm_vcpu *vcpu,
132 				const struct sys_reg_params *p)
133 {
134 	return true;
135 }
136 
137 static inline bool read_zero(struct kvm_vcpu *vcpu,
138 			     struct sys_reg_params *p)
139 {
140 	p->regval = 0;
141 	return true;
142 }
143 
144 /* Reset functions */
145 static inline u64 reset_unknown(struct kvm_vcpu *vcpu,
146 				 const struct sys_reg_desc *r)
147 {
148 	BUG_ON(!r->reg);
149 	BUG_ON(r->reg >= NR_SYS_REGS);
150 	__vcpu_assign_sys_reg(vcpu, r->reg, 0x1de7ec7edbadc0deULL);
151 	return __vcpu_sys_reg(vcpu, r->reg);
152 }
153 
154 static inline u64 reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
155 {
156 	BUG_ON(!r->reg);
157 	BUG_ON(r->reg >= NR_SYS_REGS);
158 	__vcpu_assign_sys_reg(vcpu, r->reg, r->val);
159 	return __vcpu_sys_reg(vcpu, r->reg);
160 }
161 
162 static inline unsigned int sysreg_visibility(const struct kvm_vcpu *vcpu,
163 					     const struct sys_reg_desc *r)
164 {
165 	if (likely(!r->visibility))
166 		return 0;
167 
168 	return r->visibility(vcpu, r);
169 }
170 
171 static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu,
172 				 const struct sys_reg_desc *r)
173 {
174 	return sysreg_visibility(vcpu, r) & REG_HIDDEN;
175 }
176 
177 static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu,
178 					 const struct sys_reg_desc *r)
179 {
180 	return sysreg_visibility(vcpu, r) & REG_RAZ;
181 }
182 
183 static inline bool sysreg_user_write_ignore(const struct kvm_vcpu *vcpu,
184 					    const struct sys_reg_desc *r)
185 {
186 	return sysreg_visibility(vcpu, r) & REG_USER_WI;
187 }
188 
189 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
190 			      const struct sys_reg_desc *i2)
191 {
192 	BUG_ON(i1 == i2);
193 	if (!i1)
194 		return 1;
195 	else if (!i2)
196 		return -1;
197 	if (i1->Op0 != i2->Op0)
198 		return i1->Op0 - i2->Op0;
199 	if (i1->Op1 != i2->Op1)
200 		return i1->Op1 - i2->Op1;
201 	if (i1->CRn != i2->CRn)
202 		return i1->CRn - i2->CRn;
203 	if (i1->CRm != i2->CRm)
204 		return i1->CRm - i2->CRm;
205 	return i1->Op2 - i2->Op2;
206 }
207 
208 static inline int match_sys_reg(const void *key, const void *elt)
209 {
210 	const unsigned long pval = (unsigned long)key;
211 	const struct sys_reg_desc *r = elt;
212 
213 	return pval - reg_to_encoding(r);
214 }
215 
216 static inline const struct sys_reg_desc *
217 find_reg(const struct sys_reg_params *params, const struct sys_reg_desc table[],
218 	 unsigned int num)
219 {
220 	unsigned long pval = reg_to_encoding(params);
221 
222 	return __inline_bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
223 }
224 
225 const struct sys_reg_desc *get_reg_by_id(u64 id,
226 					 const struct sys_reg_desc table[],
227 					 unsigned int num);
228 
229 int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
230 int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
231 int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
232 			 const struct sys_reg_desc table[], unsigned int num);
233 int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
234 			 const struct sys_reg_desc table[], unsigned int num);
235 
236 bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index);
237 
238 int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu);
239 
240 #define AA32(_x)	.aarch32_map = AA32_##_x
241 #define Op0(_x) 	.Op0 = _x
242 #define Op1(_x) 	.Op1 = _x
243 #define CRn(_x)		.CRn = _x
244 #define CRm(_x) 	.CRm = _x
245 #define Op2(_x) 	.Op2 = _x
246 
247 #define SYS_DESC(reg)					\
248 	.name = #reg,					\
249 	Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),	\
250 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
251 	Op2(sys_reg_Op2(reg))
252 
253 #define CP15_SYS_DESC(reg)				\
254 	.name = #reg,					\
255 	.aarch32_map = AA32_DIRECT,			\
256 	Op0(0), Op1(sys_reg_Op1(reg)),			\
257 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
258 	Op2(sys_reg_Op2(reg))
259 
260 #define ID_REG_LIMIT_FIELD_ENUM(val, reg, field, limit)			       \
261 ({									       \
262 	u64 __f_val = FIELD_GET(reg##_##field##_MASK, val);		       \
263 	(val) &= ~reg##_##field##_MASK;					       \
264 	(val) |= FIELD_PREP(reg##_##field##_MASK,			       \
265 			    min(__f_val,				       \
266 				(u64)SYS_FIELD_VALUE(reg, field, limit)));     \
267 	(val);								       \
268 })
269 
270 #define TO_ARM64_SYS_REG(r)	ARM64_SYS_REG(sys_reg_Op0(SYS_ ## r),	\
271 					      sys_reg_Op1(SYS_ ## r),	\
272 					      sys_reg_CRn(SYS_ ## r),	\
273 					      sys_reg_CRm(SYS_ ## r),	\
274 					      sys_reg_Op2(SYS_ ## r))
275 
276 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
277