xref: /openbmc/linux/arch/arm64/kvm/sys_regs.h (revision 7b6d864b)
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 	u8	Rt;
32 	bool	is_write;
33 };
34 
35 struct sys_reg_desc {
36 	/* MRS/MSR instruction which accesses it. */
37 	u8	Op0;
38 	u8	Op1;
39 	u8	CRn;
40 	u8	CRm;
41 	u8	Op2;
42 
43 	/* Trapped access from guest, if non-NULL. */
44 	bool (*access)(struct kvm_vcpu *,
45 		       const struct sys_reg_params *,
46 		       const struct sys_reg_desc *);
47 
48 	/* Initialization for vcpu. */
49 	void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
50 
51 	/* Index into sys_reg[], or 0 if we don't need to save it. */
52 	int reg;
53 
54 	/* Value (usually reset value) */
55 	u64 val;
56 };
57 
58 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
59 {
60 	/* Look, we even formatted it for you to paste into the table! */
61 	kvm_pr_unimpl(" { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
62 		      p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
63 }
64 
65 static inline bool ignore_write(struct kvm_vcpu *vcpu,
66 				const struct sys_reg_params *p)
67 {
68 	return true;
69 }
70 
71 static inline bool read_zero(struct kvm_vcpu *vcpu,
72 			     const struct sys_reg_params *p)
73 {
74 	*vcpu_reg(vcpu, p->Rt) = 0;
75 	return true;
76 }
77 
78 static inline bool write_to_read_only(struct kvm_vcpu *vcpu,
79 				      const struct sys_reg_params *params)
80 {
81 	kvm_debug("sys_reg write to read-only register at: %lx\n",
82 		  *vcpu_pc(vcpu));
83 	print_sys_reg_instr(params);
84 	return false;
85 }
86 
87 static inline bool read_from_write_only(struct kvm_vcpu *vcpu,
88 					const struct sys_reg_params *params)
89 {
90 	kvm_debug("sys_reg read to write-only register at: %lx\n",
91 		  *vcpu_pc(vcpu));
92 	print_sys_reg_instr(params);
93 	return false;
94 }
95 
96 /* Reset functions */
97 static inline void reset_unknown(struct kvm_vcpu *vcpu,
98 				 const struct sys_reg_desc *r)
99 {
100 	BUG_ON(!r->reg);
101 	BUG_ON(r->reg >= NR_SYS_REGS);
102 	vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
103 }
104 
105 static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
106 {
107 	BUG_ON(!r->reg);
108 	BUG_ON(r->reg >= NR_SYS_REGS);
109 	vcpu_sys_reg(vcpu, r->reg) = r->val;
110 }
111 
112 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
113 			      const struct sys_reg_desc *i2)
114 {
115 	BUG_ON(i1 == i2);
116 	if (!i1)
117 		return 1;
118 	else if (!i2)
119 		return -1;
120 	if (i1->Op0 != i2->Op0)
121 		return i1->Op0 - i2->Op0;
122 	if (i1->Op1 != i2->Op1)
123 		return i1->Op1 - i2->Op1;
124 	if (i1->CRn != i2->CRn)
125 		return i1->CRn - i2->CRn;
126 	if (i1->CRm != i2->CRm)
127 		return i1->CRm - i2->CRm;
128 	return i1->Op2 - i2->Op2;
129 }
130 
131 
132 #define Op0(_x) 	.Op0 = _x
133 #define Op1(_x) 	.Op1 = _x
134 #define CRn(_x)		.CRn = _x
135 #define CRm(_x) 	.CRm = _x
136 #define Op2(_x) 	.Op2 = _x
137 
138 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */
139