linux/arch/arm64/kvm/hyp/debug-sr.c
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   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
  88static 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
 120static 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
 132static 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
 151static 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
 171void __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
 197void __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
 221u32 __hyp_text __kvm_get_mdcr_el2(void)
 222{
 223        return read_sysreg(mdcr_el2);
 224}
 225
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