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
  25 #define read_debug(r,n)         read_sysreg(r##n##_el1)
  26 #define write_debug(v,r,n)      write_sysreg(v, r##n##_el1)
  27
  28 #define save_debug(ptr,reg,nr)                                          \
  29         switch (nr) {                                                   \
  30         case 15:        ptr[15] = read_debug(reg, 15);                  \
  31         case 14:        ptr[14] = read_debug(reg, 14);                  \
  32         case 13:        ptr[13] = read_debug(reg, 13);                  \
  33         case 12:        ptr[12] = read_debug(reg, 12);                  \
  34         case 11:        ptr[11] = read_debug(reg, 11);                  \
  35         case 10:        ptr[10] = read_debug(reg, 10);                  \
  36         case 9:         ptr[9] = read_debug(reg, 9);                    \
  37         case 8:         ptr[8] = read_debug(reg, 8);                    \
  38         case 7:         ptr[7] = read_debug(reg, 7);                    \
  39         case 6:         ptr[6] = read_debug(reg, 6);                    \
  40         case 5:         ptr[5] = read_debug(reg, 5);                    \
  41         case 4:         ptr[4] = read_debug(reg, 4);                    \
  42         case 3:         ptr[3] = read_debug(reg, 3);                    \
  43         case 2:         ptr[2] = read_debug(reg, 2);                    \
  44         case 1:         ptr[1] = read_debug(reg, 1);                    \
  45         default:        ptr[0] = read_debug(reg, 0);                    \
  46         }
  47
  48 #define restore_debug(ptr,reg,nr)                                       \
  49         switch (nr) {                                                   \
  50         case 15:        write_debug(ptr[15], reg, 15);                  \
  51         case 14:        write_debug(ptr[14], reg, 14);                  \
  52         case 13:        write_debug(ptr[13], reg, 13);                  \
  53         case 12:        write_debug(ptr[12], reg, 12);                  \
  54         case 11:        write_debug(ptr[11], reg, 11);                  \
  55         case 10:        write_debug(ptr[10], reg, 10);                  \
  56         case 9:         write_debug(ptr[9], reg, 9);                    \
  57         case 8:         write_debug(ptr[8], reg, 8);                    \
  58         case 7:         write_debug(ptr[7], reg, 7);                    \
  59         case 6:         write_debug(ptr[6], reg, 6);                    \
  60         case 5:         write_debug(ptr[5], reg, 5);                    \
  61         case 4:         write_debug(ptr[4], reg, 4);                    \
  62         case 3:         write_debug(ptr[3], reg, 3);                    \
  63         case 2:         write_debug(ptr[2], reg, 2);                    \
  64         case 1:         write_debug(ptr[1], reg, 1);                    \
  65         default:        write_debug(ptr[0], reg, 0);                    \
  66         }
  67
  68 #define PMSCR_EL1               sys_reg(3, 0, 9, 9, 0)
  69
  70 #define PMBLIMITR_EL1           sys_reg(3, 0, 9, 10, 0)
  71 #define PMBLIMITR_EL1_E         BIT(0)
  72
  73 #define PMBIDR_EL1              sys_reg(3, 0, 9, 10, 7)
  74 #define PMBIDR_EL1_P            BIT(4)
  75
  76 #define psb_csync()             asm volatile("hint #17")
  77
  78 static void __hyp_text __debug_save_spe_vhe(u64 *pmscr_el1)
  79 {
  80         /* The vcpu can run. but it can't hide. */
  81 }
  82
  83 static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
  84 {
  85         u64 reg;
  86
  87         /* SPE present on this CPU? */
  88         if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
  89                                                   ID_AA64DFR0_PMSVER_SHIFT))
  90                 return;
  91
  92         /* Yes; is it owned by EL3? */
  93         reg = read_sysreg_s(PMBIDR_EL1);
  94         if (reg & PMBIDR_EL1_P)
  95                 return;
  96
  97         /* No; is the host actually using the thing? */
  98         reg = read_sysreg_s(PMBLIMITR_EL1);
  99         if (!(reg & PMBLIMITR_EL1_E))
 100                 return;
 101
 102         /* Yes; save the control register and disable data generation */
 103         *pmscr_el1 = read_sysreg_s(PMSCR_EL1);
 104         write_sysreg_s(0, PMSCR_EL1);
 105         isb();
 106
 107         /* Now drain all buffered data to memory */
 108         psb_csync();
 109         dsb(nsh);
 110 }
 111
 112 static hyp_alternate_select(__debug_save_spe,
 113                             __debug_save_spe_nvhe, __debug_save_spe_vhe,
 114                             ARM64_HAS_VIRT_HOST_EXTN);
 115
 116 static void __hyp_text __debug_restore_spe(u64 pmscr_el1)
 117 {
 118         if (!pmscr_el1)
 119                 return;
 120
 121         /* The host page table is installed, but not yet synchronised */
 122         isb();
 123
 124         /* Re-enable data generation */
 125         write_sysreg_s(pmscr_el1, PMSCR_EL1);
 126 }
 127
 128 void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
 129                                    struct kvm_guest_debug_arch *dbg,
 130                                    struct kvm_cpu_context *ctxt)
 131 {
 132         u64 aa64dfr0;
 133         int brps, wrps;
 134
 135         if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
 136                 return;
 137
 138         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 139         brps = (aa64dfr0 >> 12) & 0xf;
 140         wrps = (aa64dfr0 >> 20) & 0xf;
 141
 142         save_debug(dbg->dbg_bcr, dbgbcr, brps);
 143         save_debug(dbg->dbg_bvr, dbgbvr, brps);
 144         save_debug(dbg->dbg_wcr, dbgwcr, wrps);
 145         save_debug(dbg->dbg_wvr, dbgwvr, wrps);
 146
 147         ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
 148 }
 149
 150 void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
 151                                       struct kvm_guest_debug_arch *dbg,
 152                                       struct kvm_cpu_context *ctxt)
 153 {
 154         u64 aa64dfr0;
 155         int brps, wrps;
 156
 157         if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
 158                 return;
 159
 160         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 161
 162         brps = (aa64dfr0 >> 12) & 0xf;
 163         wrps = (aa64dfr0 >> 20) & 0xf;
 164
 165         restore_debug(dbg->dbg_bcr, dbgbcr, brps);
 166         restore_debug(dbg->dbg_bvr, dbgbvr, brps);
 167         restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
 168         restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
 169
 170         write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
 171 }
 172
 173 void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu)
 174 {
 175         /* If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY is set, perform
 176          * a full save/restore cycle. */
 177         if ((vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE) ||
 178             (vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_MDE))
 179                 vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
 180
 181         __debug_save_state(vcpu, &vcpu->arch.host_debug_state.regs,
 182                            kern_hyp_va(vcpu->arch.host_cpu_context));
 183         __debug_save_spe()(&vcpu->arch.host_debug_state.pmscr_el1);
 184 }
 185
 186 void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu)
 187 {
 188         __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
 189         __debug_restore_state(vcpu, &vcpu->arch.host_debug_state.regs,
 190                               kern_hyp_va(vcpu->arch.host_cpu_context));
 191
 192         if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)
 193                 vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
 194 }
 195
 196 u32 __hyp_text __kvm_get_mdcr_el2(void)
 197 {
 198         return read_sysreg(mdcr_el2);
 199 }