arch/arm64/kvm/sys_regs.h

   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__ */