xref: /linux/arch/arm64/kvm/sys_regs.h (revision 64dd3b6a79f0907d36de481b0f15fab323a53e5a)
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 struct sys_reg_desc {
53 	/* Sysreg string for debug */
54 	const char *name;
55 
56 	enum {
57 		AA32_DIRECT,
58 		AA32_LO,
59 		AA32_HI,
60 	} aarch32_map;
61 
62 	/* MRS/MSR instruction which accesses it. */
63 	u8	Op0;
64 	u8	Op1;
65 	u8	CRn;
66 	u8	CRm;
67 	u8	Op2;
68 
69 	/* Trapped access from guest, if non-NULL. */
70 	bool (*access)(struct kvm_vcpu *,
71 		       struct sys_reg_params *,
72 		       const struct sys_reg_desc *);
73 
74 	/*
75 	 * Initialization for vcpu. Return initialized value, or KVM
76 	 * sanitized value for ID registers.
77 	 */
78 	u64 (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
79 
80 	/* Index into sys_reg[], or 0 if we don't need to save it. */
81 	int reg;
82 
83 	/* Value (usually reset value), or write mask for idregs */
84 	u64 val;
85 
86 	/* Custom get/set_user functions, fallback to generic if NULL */
87 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
88 			u64 *val);
89 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
90 			u64 val);
91 
92 	/* Return mask of REG_* runtime visibility overrides */
93 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
94 				   const struct sys_reg_desc *rd);
95 };
96 
97 #define REG_HIDDEN		(1 << 0) /* hidden from userspace and guest */
98 #define REG_RAZ			(1 << 1) /* RAZ from userspace and guest */
99 #define REG_USER_WI		(1 << 2) /* WI from userspace only */
100 
101 static __printf(2, 3)
print_sys_reg_msg(const struct sys_reg_params * p,char * fmt,...)102 inline void print_sys_reg_msg(const struct sys_reg_params *p,
103 				       char *fmt, ...)
104 {
105 	va_list va;
106 
107 	va_start(va, fmt);
108 	/* Look, we even formatted it for you to paste into the table! */
109 	kvm_pr_unimpl("%pV { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
110 		      &(struct va_format){ fmt, &va },
111 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
112 	va_end(va);
113 }
114 
print_sys_reg_instr(const struct sys_reg_params * p)115 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
116 {
117 	/* GCC warns on an empty format string */
118 	print_sys_reg_msg(p, "%s", "");
119 }
120 
ignore_write(struct kvm_vcpu * vcpu,const struct sys_reg_params * p)121 static inline bool ignore_write(struct kvm_vcpu *vcpu,
122 				const struct sys_reg_params *p)
123 {
124 	return true;
125 }
126 
read_zero(struct kvm_vcpu * vcpu,struct sys_reg_params * p)127 static inline bool read_zero(struct kvm_vcpu *vcpu,
128 			     struct sys_reg_params *p)
129 {
130 	p->regval = 0;
131 	return true;
132 }
133 
134 /* Reset functions */
reset_unknown(struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)135 static inline u64 reset_unknown(struct kvm_vcpu *vcpu,
136 				 const struct sys_reg_desc *r)
137 {
138 	BUG_ON(!r->reg);
139 	BUG_ON(r->reg >= NR_SYS_REGS);
140 	__vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
141 	return __vcpu_sys_reg(vcpu, r->reg);
142 }
143 
reset_val(struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)144 static inline u64 reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
145 {
146 	BUG_ON(!r->reg);
147 	BUG_ON(r->reg >= NR_SYS_REGS);
148 	__vcpu_sys_reg(vcpu, r->reg) = r->val;
149 	return __vcpu_sys_reg(vcpu, r->reg);
150 }
151 
sysreg_visibility(const struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)152 static inline unsigned int sysreg_visibility(const struct kvm_vcpu *vcpu,
153 					     const struct sys_reg_desc *r)
154 {
155 	if (likely(!r->visibility))
156 		return 0;
157 
158 	return r->visibility(vcpu, r);
159 }
160 
sysreg_hidden(const struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)161 static inline bool sysreg_hidden(const struct kvm_vcpu *vcpu,
162 				 const struct sys_reg_desc *r)
163 {
164 	return sysreg_visibility(vcpu, r) & REG_HIDDEN;
165 }
166 
sysreg_visible_as_raz(const struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)167 static inline bool sysreg_visible_as_raz(const struct kvm_vcpu *vcpu,
168 					 const struct sys_reg_desc *r)
169 {
170 	return sysreg_visibility(vcpu, r) & REG_RAZ;
171 }
172 
sysreg_user_write_ignore(const struct kvm_vcpu * vcpu,const struct sys_reg_desc * r)173 static inline bool sysreg_user_write_ignore(const struct kvm_vcpu *vcpu,
174 					    const struct sys_reg_desc *r)
175 {
176 	return sysreg_visibility(vcpu, r) & REG_USER_WI;
177 }
178 
cmp_sys_reg(const struct sys_reg_desc * i1,const struct sys_reg_desc * i2)179 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
180 			      const struct sys_reg_desc *i2)
181 {
182 	BUG_ON(i1 == i2);
183 	if (!i1)
184 		return 1;
185 	else if (!i2)
186 		return -1;
187 	if (i1->Op0 != i2->Op0)
188 		return i1->Op0 - i2->Op0;
189 	if (i1->Op1 != i2->Op1)
190 		return i1->Op1 - i2->Op1;
191 	if (i1->CRn != i2->CRn)
192 		return i1->CRn - i2->CRn;
193 	if (i1->CRm != i2->CRm)
194 		return i1->CRm - i2->CRm;
195 	return i1->Op2 - i2->Op2;
196 }
197 
match_sys_reg(const void * key,const void * elt)198 static inline int match_sys_reg(const void *key, const void *elt)
199 {
200 	const unsigned long pval = (unsigned long)key;
201 	const struct sys_reg_desc *r = elt;
202 
203 	return pval - reg_to_encoding(r);
204 }
205 
206 static inline const struct sys_reg_desc *
find_reg(const struct sys_reg_params * params,const struct sys_reg_desc table[],unsigned int num)207 find_reg(const struct sys_reg_params *params, const struct sys_reg_desc table[],
208 	 unsigned int num)
209 {
210 	unsigned long pval = reg_to_encoding(params);
211 
212 	return __inline_bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
213 }
214 
215 const struct sys_reg_desc *get_reg_by_id(u64 id,
216 					 const struct sys_reg_desc table[],
217 					 unsigned int num);
218 
219 int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
220 int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
221 int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
222 			 const struct sys_reg_desc table[], unsigned int num);
223 int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
224 			 const struct sys_reg_desc table[], unsigned int num);
225 
226 bool triage_sysreg_trap(struct kvm_vcpu *vcpu, int *sr_index);
227 
228 int kvm_finalize_sys_regs(struct kvm_vcpu *vcpu);
229 
230 #define AA32(_x)	.aarch32_map = AA32_##_x
231 #define Op0(_x) 	.Op0 = _x
232 #define Op1(_x) 	.Op1 = _x
233 #define CRn(_x)		.CRn = _x
234 #define CRm(_x) 	.CRm = _x
235 #define Op2(_x) 	.Op2 = _x
236 
237 #define SYS_DESC(reg)					\
238 	.name = #reg,					\
239 	Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),	\
240 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
241 	Op2(sys_reg_Op2(reg))
242 
243 #define CP15_SYS_DESC(reg)				\
244 	.name = #reg,					\
245 	.aarch32_map = AA32_DIRECT,			\
246 	Op0(0), Op1(sys_reg_Op1(reg)),			\
247 	CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),	\
248 	Op2(sys_reg_Op2(reg))
249 
250 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
251