xref: /openbmc/linux/arch/arm64/kvm/sys_regs.h (revision 78700c0a)
1 /*
2  * Copyright (C) 2012,2013 - ARM Ltd
3  * Author: Marc Zyngier <marc.zyngier@arm.com>
4  *
5  * Derived from arch/arm/kvm/coproc.h
6  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
7  * Authors: Christoffer Dall <c.dall@virtualopensystems.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License, version 2, as
11  * published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #ifndef __ARM64_KVM_SYS_REGS_LOCAL_H__
23 #define __ARM64_KVM_SYS_REGS_LOCAL_H__
24 
25 struct sys_reg_params {
26 	u8	Op0;
27 	u8	Op1;
28 	u8	CRn;
29 	u8	CRm;
30 	u8	Op2;
31 	u64	regval;
32 	bool	is_write;
33 	bool	is_aarch32;
34 	bool	is_32bit;	/* Only valid if is_aarch32 is true */
35 };
36 
37 struct sys_reg_desc {
38 	/* MRS/MSR instruction which accesses it. */
39 	u8	Op0;
40 	u8	Op1;
41 	u8	CRn;
42 	u8	CRm;
43 	u8	Op2;
44 
45 	/* Trapped access from guest, if non-NULL. */
46 	bool (*access)(struct kvm_vcpu *,
47 		       struct sys_reg_params *,
48 		       const struct sys_reg_desc *);
49 
50 	/* Initialization for vcpu. */
51 	void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
52 
53 	/* Index into sys_reg[], or 0 if we don't need to save it. */
54 	int reg;
55 
56 	/* Value (usually reset value) */
57 	u64 val;
58 
59 	/* Custom get/set_user functions, fallback to generic if NULL */
60 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
61 			const struct kvm_one_reg *reg, void __user *uaddr);
62 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
63 			const struct kvm_one_reg *reg, void __user *uaddr);
64 };
65 
66 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
67 {
68 	/* Look, we even formatted it for you to paste into the table! */
69 	kvm_pr_unimpl(" { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
70 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
71 }
72 
73 static inline bool ignore_write(struct kvm_vcpu *vcpu,
74 				const struct sys_reg_params *p)
75 {
76 	return true;
77 }
78 
79 static inline bool read_zero(struct kvm_vcpu *vcpu,
80 			     struct sys_reg_params *p)
81 {
82 	p->regval = 0;
83 	return true;
84 }
85 
86 static inline bool write_to_read_only(struct kvm_vcpu *vcpu,
87 				      const struct sys_reg_params *params)
88 {
89 	kvm_debug("sys_reg write to read-only register at: %lx\n",
90 		  *vcpu_pc(vcpu));
91 	print_sys_reg_instr(params);
92 	return false;
93 }
94 
95 static inline bool read_from_write_only(struct kvm_vcpu *vcpu,
96 					const struct sys_reg_params *params)
97 {
98 	kvm_debug("sys_reg read to write-only register at: %lx\n",
99 		  *vcpu_pc(vcpu));
100 	print_sys_reg_instr(params);
101 	return false;
102 }
103 
104 /* Reset functions */
105 static inline void reset_unknown(struct kvm_vcpu *vcpu,
106 				 const struct sys_reg_desc *r)
107 {
108 	BUG_ON(!r->reg);
109 	BUG_ON(r->reg >= NR_SYS_REGS);
110 	vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
111 }
112 
113 static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
114 {
115 	BUG_ON(!r->reg);
116 	BUG_ON(r->reg >= NR_SYS_REGS);
117 	vcpu_sys_reg(vcpu, r->reg) = r->val;
118 }
119 
120 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
121 			      const struct sys_reg_desc *i2)
122 {
123 	BUG_ON(i1 == i2);
124 	if (!i1)
125 		return 1;
126 	else if (!i2)
127 		return -1;
128 	if (i1->Op0 != i2->Op0)
129 		return i1->Op0 - i2->Op0;
130 	if (i1->Op1 != i2->Op1)
131 		return i1->Op1 - i2->Op1;
132 	if (i1->CRn != i2->CRn)
133 		return i1->CRn - i2->CRn;
134 	if (i1->CRm != i2->CRm)
135 		return i1->CRm - i2->CRm;
136 	return i1->Op2 - i2->Op2;
137 }
138 
139 
140 #define Op0(_x) 	.Op0 = _x
141 #define Op1(_x) 	.Op1 = _x
142 #define CRn(_x)		.CRn = _x
143 #define CRm(_x) 	.CRm = _x
144 #define Op2(_x) 	.Op2 = _x
145 
146 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
147