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

   1 /*
   2  * Copyright (C) 2015 - ARM Ltd
   3  * Author: Marc Zyngier <marc.zyngier@arm.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/compiler.h>
  19 #include <linux/kvm_host.h>
  20
  21 #include <asm/debug-monitors.h>
  22 #include <asm/kvm_asm.h>
  23 #include <asm/kvm_hyp.h>
  24 #include <asm/kvm_mmu.h>
  25
  26 #define read_debug(r,n)         read_sysreg(r##n##_el1)
  27 #define write_debug(v,r,n)      write_sysreg(v, r##n##_el1)
  28
  29 #define save_debug(ptr,reg,nr)                                          \
  30         switch (nr) {                                                   \
  31         case 15:        ptr[15] = read_debug(reg, 15);                  \
  32         case 14:        ptr[14] = read_debug(reg, 14);                  \
  33         case 13:        ptr[13] = read_debug(reg, 13);                  \
  34         case 12:        ptr[12] = read_debug(reg, 12);                  \
  35         case 11:        ptr[11] = read_debug(reg, 11);                  \
  36         case 10:        ptr[10] = read_debug(reg, 10);                  \
  37         case 9:         ptr[9] = read_debug(reg, 9);                    \
  38         case 8:         ptr[8] = read_debug(reg, 8);                    \
  39         case 7:         ptr[7] = read_debug(reg, 7);                    \
  40         case 6:         ptr[6] = read_debug(reg, 6);                    \
  41         case 5:         ptr[5] = read_debug(reg, 5);                    \
  42         case 4:         ptr[4] = read_debug(reg, 4);                    \
  43         case 3:         ptr[3] = read_debug(reg, 3);                    \
  44         case 2:         ptr[2] = read_debug(reg, 2);                    \
  45         case 1:         ptr[1] = read_debug(reg, 1);                    \
  46         default:        ptr[0] = read_debug(reg, 0);                    \
  47         }
  48
  49 #define restore_debug(ptr,reg,nr)                                       \
  50         switch (nr) {                                                   \
  51         case 15:        write_debug(ptr[15], reg, 15);                  \
  52         case 14:        write_debug(ptr[14], reg, 14);                  \
  53         case 13:        write_debug(ptr[13], reg, 13);                  \
  54         case 12:        write_debug(ptr[12], reg, 12);                  \
  55         case 11:        write_debug(ptr[11], reg, 11);                  \
  56         case 10:        write_debug(ptr[10], reg, 10);                  \
  57         case 9:         write_debug(ptr[9], reg, 9);                    \
  58         case 8:         write_debug(ptr[8], reg, 8);                    \
  59         case 7:         write_debug(ptr[7], reg, 7);                    \
  60         case 6:         write_debug(ptr[6], reg, 6);                    \
  61         case 5:         write_debug(ptr[5], reg, 5);                    \
  62         case 4:         write_debug(ptr[4], reg, 4);                    \
  63         case 3:         write_debug(ptr[3], reg, 3);                    \
  64         case 2:         write_debug(ptr[2], reg, 2);                    \
  65         case 1:         write_debug(ptr[1], reg, 1);                    \
  66         default:        write_debug(ptr[0], reg, 0);                    \
  67         }
  68
  69 static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
  70 {
  71         u64 reg;
  72
  73         /* Clear pmscr in case of early return */
  74         *pmscr_el1 = 0;
  75
  76         /* SPE present on this CPU? */
  77         if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
  78                                                   ID_AA64DFR0_PMSVER_SHIFT))
  79                 return;
  80
  81         /* Yes; is it owned by EL3? */
  82         reg = read_sysreg_s(SYS_PMBIDR_EL1);
  83         if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
  84                 return;
  85
  86         /* No; is the host actually using the thing? */
  87         reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
  88         if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
  89                 return;
  90
  91         /* Yes; save the control register and disable data generation */
  92         *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
  93         write_sysreg_s(0, SYS_PMSCR_EL1);
  94         isb();
  95
  96         /* Now drain all buffered data to memory */
  97         psb_csync();
  98         dsb(nsh);
  99 }
 100
 101 static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
 102 {
 103         if (!pmscr_el1)
 104                 return;
 105
 106         /* The host page table is installed, but not yet synchronised */
 107         isb();
 108
 109         /* Re-enable data generation */
 110         write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
 111 }
 112
 113 static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
 114                                           struct kvm_guest_debug_arch *dbg,
 115                                           struct kvm_cpu_context *ctxt)
 116 {
 117         u64 aa64dfr0;
 118         int brps, wrps;
 119
 120         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 121         brps = (aa64dfr0 >> 12) & 0xf;
 122         wrps = (aa64dfr0 >> 20) & 0xf;
 123
 124         save_debug(dbg->dbg_bcr, dbgbcr, brps);
 125         save_debug(dbg->dbg_bvr, dbgbvr, brps);
 126         save_debug(dbg->dbg_wcr, dbgwcr, wrps);
 127         save_debug(dbg->dbg_wvr, dbgwvr, wrps);
 128
 129         ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
 130 }
 131
 132 static void __hyp_text __debug_restore_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
 141         brps = (aa64dfr0 >> 12) & 0xf;
 142         wrps = (aa64dfr0 >> 20) & 0xf;
 143
 144         restore_debug(dbg->dbg_bcr, dbgbcr, brps);
 145         restore_debug(dbg->dbg_bvr, dbgbvr, brps);
 146         restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
 147         restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
 148
 149         write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
 150 }
 151
 152 void __hyp_text __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 153 {
 154         /*
 155          * Non-VHE: Disable and flush SPE data generation
 156          * VHE: The vcpu can run, but it can't hide.
 157          */
 158         __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
 159
 160 }
 161
 162 void __hyp_text __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 163 {
 164         __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
 165 }
 166
 167 void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
 168 {
 169         struct kvm_cpu_context *host_ctxt;
 170         struct kvm_cpu_context *guest_ctxt;
 171         struct kvm_guest_debug_arch *host_dbg;
 172         struct kvm_guest_debug_arch *guest_dbg;
 173
 174         if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
 175                 return;
 176
 177         host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
 178         guest_ctxt = &vcpu->arch.ctxt;
 179         host_dbg = &vcpu->arch.host_debug_state.regs;
 180         guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 181
 182         __debug_save_state(vcpu, host_dbg, host_ctxt);
 183         __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
 184 }
 185
 186 void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
 187 {
 188         struct kvm_cpu_context *host_ctxt;
 189         struct kvm_cpu_context *guest_ctxt;
 190         struct kvm_guest_debug_arch *host_dbg;
 191         struct kvm_guest_debug_arch *guest_dbg;
 192
 193
 194         if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
 195                 return;
 196
 197         host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
 198         guest_ctxt = &vcpu->arch.ctxt;
 199         host_dbg = &vcpu->arch.host_debug_state.regs;
 200         guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 201
 202         __debug_save_state(vcpu, guest_dbg, guest_ctxt);
 203         __debug_restore_state(vcpu, host_dbg, host_ctxt);
 204
 205         vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
 206 }
 207
 208 u32 __hyp_text __kvm_get_mdcr_el2(void)
 209 {
 210         return read_sysreg(mdcr_el2);
 211 }