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_vhe(u64 *pmscr_el1)
  70 {
  71         /* The vcpu can run. but it can't hide. */
  72 }
  73
  74 static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
  75 {
  76         u64 reg;
  77
  78         /* Clear pmscr in case of early return */
  79         *pmscr_el1 = 0;
  80
  81         /* SPE present on this CPU? */
  82         if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
  83                                                   ID_AA64DFR0_PMSVER_SHIFT))
  84                 return;
  85
  86         /* Yes; is it owned by EL3? */
  87         reg = read_sysreg_s(SYS_PMBIDR_EL1);
  88         if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
  89                 return;
  90
  91         /* No; is the host actually using the thing? */
  92         reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
  93         if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
  94                 return;
  95
  96         /* Yes; save the control register and disable data generation */
  97         *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
  98         write_sysreg_s(0, SYS_PMSCR_EL1);
  99         isb();
 100
 101         /* Now drain all buffered data to memory */
 102         psb_csync();
 103         dsb(nsh);
 104 }
 105
 106 static hyp_alternate_select(__debug_save_spe,
 107                             __debug_save_spe_nvhe, __debug_save_spe_vhe,
 108                             ARM64_HAS_VIRT_HOST_EXTN);
 109
 110 static void __hyp_text __debug_restore_spe(u64 pmscr_el1)
 111 {
 112         if (!pmscr_el1)
 113                 return;
 114
 115         /* The host page table is installed, but not yet synchronised */
 116         isb();
 117
 118         /* Re-enable data generation */
 119         write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
 120 }
 121
 122 void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
 123                                    struct kvm_guest_debug_arch *dbg,
 124                                    struct kvm_cpu_context *ctxt)
 125 {
 126         u64 aa64dfr0;
 127         int brps, wrps;
 128
 129         if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
 130                 return;
 131
 132         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 133         brps = (aa64dfr0 >> 12) & 0xf;
 134         wrps = (aa64dfr0 >> 20) & 0xf;
 135
 136         save_debug(dbg->dbg_bcr, dbgbcr, brps);
 137         save_debug(dbg->dbg_bvr, dbgbvr, brps);
 138         save_debug(dbg->dbg_wcr, dbgwcr, wrps);
 139         save_debug(dbg->dbg_wvr, dbgwvr, wrps);
 140
 141         ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
 142 }
 143
 144 void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
 145                                       struct kvm_guest_debug_arch *dbg,
 146                                       struct kvm_cpu_context *ctxt)
 147 {
 148         u64 aa64dfr0;
 149         int brps, wrps;
 150
 151         if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
 152                 return;
 153
 154         aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
 155
 156         brps = (aa64dfr0 >> 12) & 0xf;
 157         wrps = (aa64dfr0 >> 20) & 0xf;
 158
 159         restore_debug(dbg->dbg_bcr, dbgbcr, brps);
 160         restore_debug(dbg->dbg_bvr, dbgbvr, brps);
 161         restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
 162         restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
 163
 164         write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
 165 }
 166
 167 void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu)
 168 {
 169         /* If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY is set, perform
 170          * a full save/restore cycle. */
 171         if ((vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE) ||
 172             (vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_MDE))
 173                 vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
 174
 175         __debug_save_state(vcpu, &vcpu->arch.host_debug_state.regs,
 176                            kern_hyp_va(vcpu->arch.host_cpu_context));
 177         __debug_save_spe()(&vcpu->arch.host_debug_state.pmscr_el1);
 178 }
 179
 180 void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu)
 181 {
 182         __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
 183         __debug_restore_state(vcpu, &vcpu->arch.host_debug_state.regs,
 184                               kern_hyp_va(vcpu->arch.host_cpu_context));
 185
 186         if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)
 187                 vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
 188 }
 189
 190 u32 __hyp_text __kvm_get_mdcr_el2(void)
 191 {
 192         return read_sysreg(mdcr_el2);
 193 }