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 struct sys_reg_params {
  15         u8      Op0;
  16         u8      Op1;
  17         u8      CRn;
  18         u8      CRm;
  19         u8      Op2;
  20         u64     regval;
  21         bool    is_write;
  22         bool    is_aarch32;
  23         bool    is_32bit;       /* Only valid if is_aarch32 is true */
  24 };
  25
  26 struct sys_reg_desc {
  27         /* Sysreg string for debug */
  28         const char *name;
  29
  30         /* MRS/MSR instruction which accesses it. */
  31         u8      Op0;
  32         u8      Op1;
  33         u8      CRn;
  34         u8      CRm;
  35         u8      Op2;
  36
  37         /* Trapped access from guest, if non-NULL. */
  38         bool (*access)(struct kvm_vcpu *,
  39                        struct sys_reg_params *,
  40                        const struct sys_reg_desc *);
  41
  42         /* Initialization for vcpu. */
  43         void (*reset)(struct kvm_vcpu *, const struct sys_reg_desc *);
  44
  45         /* Index into sys_reg[], or 0 if we don't need to save it. */
  46         int reg;
  47
  48         /* Value (usually reset value) */
  49         u64 val;
  50
  51         /* Custom get/set_user functions, fallback to generic if NULL */
  52         int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
  53                         const struct kvm_one_reg *reg, void __user *uaddr);
  54         int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
  55                         const struct kvm_one_reg *reg, void __user *uaddr);
  56
  57         /* Return mask of REG_* runtime visibility overrides */
  58         unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
  59                                    const struct sys_reg_desc *rd);
  60 };
  61
  62 #define REG_HIDDEN_USER         (1 << 0) /* hidden from userspace ioctls */
  63 #define REG_HIDDEN_GUEST        (1 << 1) /* hidden from guest */
  64
  65 static inline void print_sys_reg_instr(const struct sys_reg_params *p)
  66 {
  67         /* Look, we even formatted it for you to paste into the table! */
  68         kvm_pr_unimpl(" { Op0(%2u), Op1(%2u), CRn(%2u), CRm(%2u), Op2(%2u), func_%s },\n",
  69                       p->Op0, p->Op1, p->CRn, p->CRm, p->Op2, p->is_write ? "write" : "read");
  70 }
  71
  72 static inline bool ignore_write(struct kvm_vcpu *vcpu,
  73                                 const struct sys_reg_params *p)
  74 {
  75         return true;
  76 }
  77
  78 static inline bool read_zero(struct kvm_vcpu *vcpu,
  79                              struct sys_reg_params *p)
  80 {
  81         p->regval = 0;
  82         return true;
  83 }
  84
  85 /* Reset functions */
  86 static inline void reset_unknown(struct kvm_vcpu *vcpu,
  87                                  const struct sys_reg_desc *r)
  88 {
  89         BUG_ON(!r->reg);
  90         BUG_ON(r->reg >= NR_SYS_REGS);
  91         __vcpu_sys_reg(vcpu, r->reg) = 0x1de7ec7edbadc0deULL;
  92 }
  93
  94 static inline void reset_val(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
  95 {
  96         BUG_ON(!r->reg);
  97         BUG_ON(r->reg >= NR_SYS_REGS);
  98         __vcpu_sys_reg(vcpu, r->reg) = r->val;
  99 }
 100
 101 static inline bool sysreg_hidden_from_guest(const struct kvm_vcpu *vcpu,
 102                                             const struct sys_reg_desc *r)
 103 {
 104         if (likely(!r->visibility))
 105                 return false;
 106
 107         return r->visibility(vcpu, r) & REG_HIDDEN_GUEST;
 108 }
 109
 110 static inline bool sysreg_hidden_from_user(const struct kvm_vcpu *vcpu,
 111                                            const struct sys_reg_desc *r)
 112 {
 113         if (likely(!r->visibility))
 114                 return false;
 115
 116         return r->visibility(vcpu, r) & REG_HIDDEN_USER;
 117 }
 118
 119 static inline int cmp_sys_reg(const struct sys_reg_desc *i1,
 120                               const struct sys_reg_desc *i2)
 121 {
 122         BUG_ON(i1 == i2);
 123         if (!i1)
 124                 return 1;
 125         else if (!i2)
 126                 return -1;
 127         if (i1->Op0 != i2->Op0)
 128                 return i1->Op0 - i2->Op0;
 129         if (i1->Op1 != i2->Op1)
 130                 return i1->Op1 - i2->Op1;
 131         if (i1->CRn != i2->CRn)
 132                 return i1->CRn - i2->CRn;
 133         if (i1->CRm != i2->CRm)
 134                 return i1->CRm - i2->CRm;
 135         return i1->Op2 - i2->Op2;
 136 }
 137
 138 const struct sys_reg_desc *find_reg_by_id(u64 id,
 139                                           struct sys_reg_params *params,
 140                                           const struct sys_reg_desc table[],
 141                                           unsigned int num);
 142
 143 #define Op0(_x)         .Op0 = _x
 144 #define Op1(_x)         .Op1 = _x
 145 #define CRn(_x)         .CRn = _x
 146 #define CRm(_x)         .CRm = _x
 147 #define Op2(_x)         .Op2 = _x
 148
 149 #define SYS_DESC(reg)                                   \
 150         .name = #reg,                                   \
 151         Op0(sys_reg_Op0(reg)), Op1(sys_reg_Op1(reg)),   \
 152         CRn(sys_reg_CRn(reg)), CRm(sys_reg_CRm(reg)),   \
 153         Op2(sys_reg_Op2(reg))
 154
 155 #endif /* __ARM64_KVM_SYS_REGS_LOCAL_H__ */