arch/arm64/kvm/hyp/debug-sr.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 - ARM Ltd
   4  * Author: Marc Zyngier <marc.zyngier@arm.com>
   5  */
   6
   7 #include <linux/compiler.h>
   8 #include <linux/kvm_host.h>
   9
  10 #include <asm/debug-monitors.h>
  11 #include <asm/kvm_asm.h>
  12 #include <asm/kvm_hyp.h>
  13 #include <asm/kvm_mmu.h>
  14
  15 #define read_debug(r,n)         read_sysreg(r##n##_el1)
  16 #define write_debug(v,r,n)      write_sysreg(v, r##n##_el1)
  17
  18 #define save_debug(ptr,reg,nr)                                          \
  19         switch (nr) {                                                   \
  20         case 15:        ptr[15] = read_debug(reg, 15);                  \
  21                         /* Fall through */                              \
  22         case 14:        ptr[14] = read_debug(reg, 14);                  \
  23                         /* Fall through */                              \
  24         case 13:        ptr[13] = read_debug(reg, 13);                  \
  25                         /* Fall through */                              \
  26         case 12:        ptr[12] = read_debug(reg, 12);                  \
  27                         /* Fall through */                              \
  28         case 11:        ptr[11] = read_debug(reg, 11);                  \
  29                         /* Fall through */                              \
  30         case 10:        ptr[10] = read_debug(reg, 10);                  \
  31                         /* Fall through */                              \
  32         case 9:         ptr[9] = read_debug(reg, 9);                    \
  33                         /* Fall through */                              \
  34         case 8:         ptr[8] = read_debug(reg, 8);                    \
  35                         /* Fall through */                              \
  36         case 7:         ptr[7] = read_debug(reg, 7);                    \
  37                         /* Fall through */                              \
  38         case 6:         ptr[6] = read_debug(reg, 6);                    \
  39                         /* Fall through */                              \
  40         case 5:         ptr[5] = read_debug(reg, 5);                    \
  41                         /* Fall through */                              \
  42         case 4:         ptr[4] = read_debug(reg, 4);                    \
  43                         /* Fall through */                              \
  44         case 3:         ptr[3] = read_debug(reg, 3);                    \
  45                         /* Fall through */                              \
  46         case 2:         ptr[2] = read_debug(reg, 2);                    \
  47                         /* Fall through */                              \
  48         case 1:         ptr[1] = read_debug(reg, 1);                    \
  49                         /* Fall through */                              \
  50         default:        ptr[0] = read_debug(reg, 0);                    \
  51         }
  52
  53 #define restore_debug(ptr,reg,nr)                                       \
  54         switch (nr) {                                                   \
  55         case 15:        write_debug(ptr[15], reg, 15);                  \
  56                         /* Fall through */                              \
  57         case 14:        write_debug(ptr[14], reg, 14);                  \
  58                         /* Fall through */                              \
  59         case 13:        write_debug(ptr[13], reg, 13);                  \
  60                         /* Fall through */                              \
  61         case 12:        write_debug(ptr[12], reg, 12);                  \
  62                         /* Fall through */                              \
  63         case 11:        write_debug(ptr[11], reg, 11);                  \
  64                         /* Fall through */                              \
  65         case 10:        write_debug(ptr[10], reg, 10);                  \
  66                         /* Fall through */                              \
  67         case 9:         write_debug(ptr[9], reg, 9);                    \
  68                         /* Fall through */                              \
  69         case 8:         write_debug(ptr[8], reg, 8);                    \
  70                         /* Fall through */                              \
  71         case 7:         write_debug(ptr[7], reg, 7);                    \
  72                         /* Fall through */                              \
  73         case 6:         write_debug(ptr[6], reg, 6);                    \
  74                         /* Fall through */                              \
  75         case 5:         write_debug(ptr[5], reg, 5);                    \
  76                         /* Fall through */                              \
  77         case 4:         write_debug(ptr[4], reg, 4);                    \
  78                         /* Fall through */                              \
  79         case 3:         write_debug(ptr[3], reg, 3);                    \
  80                         /* Fall through */                              \
  81         case 2:         write_debug(ptr[2], reg, 2);                    \
  82                         /* Fall through */                              \
  83         case 1:         write_debug(ptr[1], reg, 1);                    \
  84                         /* Fall through */                              \
  85         default:        write_debug(ptr[0], reg, 0);                    \
  86         }
  87
  88 static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
  89 {
  90         u64 reg;
  91
  92         /* Clear pmscr in case of early return */
  93         *pmscr_el1 = 0;
  94
  95         /* SPE present on this CPU? */
  96         if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
  97                                                   ID_AA64DFR0_PMSVER_SHIFT))
  98                 return;
  99
 100         /* Yes; is it owned by EL3? */
 101         reg = read_sysreg_s(SYS_PMBIDR_EL1);
 102         if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
 103                 return;
 104
 105         /* No; is the host actually using the thing? */
 106         reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
 107         if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
 108                 return;
 109
 110         /* Yes; save the control register and disable data generation */
 111         *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
 112         write_sysreg_s(0, SYS_PMSCR_EL1);
 113         isb();
 114
 115         /* Now drain all buffered data to memory */
 116         psb_csync();
 117         dsb(nsh);
 118 }
 119
 120 static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
 121 {
 122         if (!pmscr_el1)
 123                 return;
 124
 125         /* The host page table is installed, but not yet synchronised */
 126         isb();
 127
 128         /* Re-enable data generation */
 129         write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
 130 }
 131
 132 static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
 133                                           struct kvm_guest_debug_arch *dbg,
 134                                           struct kvm_cpu_context *ctxt)
 135 {
 136         u64 aa64dfr0;
 137         int brps, wrps;
 138
 139         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 140         brps = (aa64dfr0 >> 12) & 0xf;
 141         wrps = (aa64dfr0 >> 20) & 0xf;
 142
 143         save_debug(dbg->dbg_bcr, dbgbcr, brps);
 144         save_debug(dbg->dbg_bvr, dbgbvr, brps);
 145         save_debug(dbg->dbg_wcr, dbgwcr, wrps);
 146         save_debug(dbg->dbg_wvr, dbgwvr, wrps);
 147
 148         ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
 149 }
 150
 151 static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
 152                                              struct kvm_guest_debug_arch *dbg,
 153                                              struct kvm_cpu_context *ctxt)
 154 {
 155         u64 aa64dfr0;
 156         int brps, wrps;
 157
 158         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 159
 160         brps = (aa64dfr0 >> 12) & 0xf;
 161         wrps = (aa64dfr0 >> 20) & 0xf;
 162
 163         restore_debug(dbg->dbg_bcr, dbgbcr, brps);
 164         restore_debug(dbg->dbg_bvr, dbgbvr, brps);
 165         restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
 166         restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
 167
 168         write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
 169 }
 170
 171 void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
 172 {
 173         struct kvm_cpu_context *host_ctxt;
 174         struct kvm_cpu_context *guest_ctxt;
 175         struct kvm_guest_debug_arch *host_dbg;
 176         struct kvm_guest_debug_arch *guest_dbg;
 177
 178         /*
 179          * Non-VHE: Disable and flush SPE data generation
 180          * VHE: The vcpu can run, but it can't hide.
 181          */
 182         if (!has_vhe())
 183                 __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
 184
 185         if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
 186                 return;
 187
 188         host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
 189         guest_ctxt = &vcpu->arch.ctxt;
 190         host_dbg = &vcpu->arch.host_debug_state.regs;
 191         guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 192
 193         __debug_save_state(vcpu, host_dbg, host_ctxt);
 194         __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
 195 }
 196
 197 void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
 198 {
 199         struct kvm_cpu_context *host_ctxt;
 200         struct kvm_cpu_context *guest_ctxt;
 201         struct kvm_guest_debug_arch *host_dbg;
 202         struct kvm_guest_debug_arch *guest_dbg;
 203
 204         if (!has_vhe())
 205                 __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
 206
 207         if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
 208                 return;
 209
 210         host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
 211         guest_ctxt = &vcpu->arch.ctxt;
 212         host_dbg = &vcpu->arch.host_debug_state.regs;
 213         guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 214
 215         __debug_save_state(vcpu, guest_dbg, guest_ctxt);
 216         __debug_restore_state(vcpu, host_dbg, host_ctxt);
 217
 218         vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
 219 }
 220
 221 u32 __hyp_text __kvm_get_mdcr_el2(void)
 222 {
 223         return read_sysreg(mdcr_el2);
 224 }