arch/arm64/kvm/sys_regs.h

   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)
 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
 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
 121 static inline bool ignore_write(struct kvm_vcpu *vcpu,
 122                                 const struct sys_reg_params *p)
 123 {
 124         return true;
 125 }
 126
 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 */
 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
 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
 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
 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
 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
 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
 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
 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 *
 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__ */