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 <hyp/adjust_pc.h> 8 #include <hyp/switch.h> 9 #include <hyp/sysreg-sr.h> 10 11 #include <linux/arm-smccc.h> 12 #include <linux/kvm_host.h> 13 #include <linux/types.h> 14 #include <linux/jump_label.h> 15 #include <uapi/linux/psci.h> 16 17 #include <kvm/arm_psci.h> 18 19 #include <asm/barrier.h> 20 #include <asm/cpufeature.h> 21 #include <asm/kprobes.h> 22 #include <asm/kvm_asm.h> 23 #include <asm/kvm_emulate.h> 24 #include <asm/kvm_hyp.h> 25 #include <asm/kvm_mmu.h> 26 #include <asm/fpsimd.h> 27 #include <asm/debug-monitors.h> 28 #include <asm/processor.h> 29 #include <asm/thread_info.h> 30 31 /* Non-VHE specific context */ 32 DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); 33 DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); 34 DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); 35 36 static void __activate_traps(struct kvm_vcpu *vcpu) 37 { 38 u64 val; 39 40 ___activate_traps(vcpu); 41 __activate_traps_common(vcpu); 42 43 val = CPTR_EL2_DEFAULT; 44 val |= CPTR_EL2_TTA | CPTR_EL2_TZ | CPTR_EL2_TAM; 45 if (!update_fp_enabled(vcpu)) { 46 val |= CPTR_EL2_TFP; 47 __activate_traps_fpsimd32(vcpu); 48 } 49 50 write_sysreg(val, cptr_el2); 51 write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2); 52 53 if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { 54 struct kvm_cpu_context *ctxt = &vcpu->arch.ctxt; 55 56 isb(); 57 /* 58 * At this stage, and thanks to the above isb(), S2 is 59 * configured and enabled. We can now restore the guest's S1 60 * configuration: SCTLR, and only then TCR. 61 */ 62 write_sysreg_el1(ctxt_sys_reg(ctxt, SCTLR_EL1), SYS_SCTLR); 63 isb(); 64 write_sysreg_el1(ctxt_sys_reg(ctxt, TCR_EL1), SYS_TCR); 65 } 66 } 67 68 static void __deactivate_traps(struct kvm_vcpu *vcpu) 69 { 70 extern char __kvm_hyp_host_vector[]; 71 u64 mdcr_el2; 72 73 ___deactivate_traps(vcpu); 74 75 mdcr_el2 = read_sysreg(mdcr_el2); 76 77 if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { 78 u64 val; 79 80 /* 81 * Set the TCR and SCTLR registers in the exact opposite 82 * sequence as __activate_traps (first prevent walks, 83 * then force the MMU on). A generous sprinkling of isb() 84 * ensure that things happen in this exact order. 85 */ 86 val = read_sysreg_el1(SYS_TCR); 87 write_sysreg_el1(val | TCR_EPD1_MASK | TCR_EPD0_MASK, SYS_TCR); 88 isb(); 89 val = read_sysreg_el1(SYS_SCTLR); 90 write_sysreg_el1(val | SCTLR_ELx_M, SYS_SCTLR); 91 isb(); 92 } 93 94 __deactivate_traps_common(); 95 96 mdcr_el2 &= MDCR_EL2_HPMN_MASK; 97 mdcr_el2 |= MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT; 98 99 write_sysreg(mdcr_el2, mdcr_el2); 100 if (is_protected_kvm_enabled()) 101 write_sysreg(HCR_HOST_NVHE_PROTECTED_FLAGS, hcr_el2); 102 else 103 write_sysreg(HCR_HOST_NVHE_FLAGS, hcr_el2); 104 write_sysreg(CPTR_EL2_DEFAULT, cptr_el2); 105 write_sysreg(__kvm_hyp_host_vector, vbar_el2); 106 } 107 108 static void __load_host_stage2(void) 109 { 110 write_sysreg(0, vttbr_el2); 111 } 112 113 /* Save VGICv3 state on non-VHE systems */ 114 static void __hyp_vgic_save_state(struct kvm_vcpu *vcpu) 115 { 116 if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { 117 __vgic_v3_save_state(&vcpu->arch.vgic_cpu.vgic_v3); 118 __vgic_v3_deactivate_traps(&vcpu->arch.vgic_cpu.vgic_v3); 119 } 120 } 121 122 /* Restore VGICv3 state on non_VEH systems */ 123 static void __hyp_vgic_restore_state(struct kvm_vcpu *vcpu) 124 { 125 if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) { 126 __vgic_v3_activate_traps(&vcpu->arch.vgic_cpu.vgic_v3); 127 __vgic_v3_restore_state(&vcpu->arch.vgic_cpu.vgic_v3); 128 } 129 } 130 131 /** 132 * Disable host events, enable guest events 133 */ 134 static bool __pmu_switch_to_guest(struct kvm_cpu_context *host_ctxt) 135 { 136 struct kvm_host_data *host; 137 struct kvm_pmu_events *pmu; 138 139 host = container_of(host_ctxt, struct kvm_host_data, host_ctxt); 140 pmu = &host->pmu_events; 141 142 if (pmu->events_host) 143 write_sysreg(pmu->events_host, pmcntenclr_el0); 144 145 if (pmu->events_guest) 146 write_sysreg(pmu->events_guest, pmcntenset_el0); 147 148 return (pmu->events_host || pmu->events_guest); 149 } 150 151 /** 152 * Disable guest events, enable host events 153 */ 154 static void __pmu_switch_to_host(struct kvm_cpu_context *host_ctxt) 155 { 156 struct kvm_host_data *host; 157 struct kvm_pmu_events *pmu; 158 159 host = container_of(host_ctxt, struct kvm_host_data, host_ctxt); 160 pmu = &host->pmu_events; 161 162 if (pmu->events_guest) 163 write_sysreg(pmu->events_guest, pmcntenclr_el0); 164 165 if (pmu->events_host) 166 write_sysreg(pmu->events_host, pmcntenset_el0); 167 } 168 169 /* Switch to the guest for legacy non-VHE systems */ 170 int __kvm_vcpu_run(struct kvm_vcpu *vcpu) 171 { 172 struct kvm_cpu_context *host_ctxt; 173 struct kvm_cpu_context *guest_ctxt; 174 bool pmu_switch_needed; 175 u64 exit_code; 176 177 /* 178 * Having IRQs masked via PMR when entering the guest means the GIC 179 * will not signal the CPU of interrupts of lower priority, and the 180 * only way to get out will be via guest exceptions. 181 * Naturally, we want to avoid this. 182 */ 183 if (system_uses_irq_prio_masking()) { 184 gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); 185 pmr_sync(); 186 } 187 188 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; 189 host_ctxt->__hyp_running_vcpu = vcpu; 190 guest_ctxt = &vcpu->arch.ctxt; 191 192 pmu_switch_needed = __pmu_switch_to_guest(host_ctxt); 193 194 __sysreg_save_state_nvhe(host_ctxt); 195 /* 196 * We must flush and disable the SPE buffer for nVHE, as 197 * the translation regime(EL1&0) is going to be loaded with 198 * that of the guest. And we must do this before we change the 199 * translation regime to EL2 (via MDCR_EL2_E2PB == 0) and 200 * before we load guest Stage1. 201 */ 202 __debug_save_host_buffers_nvhe(vcpu); 203 204 __adjust_pc(vcpu); 205 206 /* 207 * We must restore the 32-bit state before the sysregs, thanks 208 * to erratum #852523 (Cortex-A57) or #853709 (Cortex-A72). 209 * 210 * Also, and in order to be able to deal with erratum #1319537 (A57) 211 * and #1319367 (A72), we must ensure that all VM-related sysreg are 212 * restored before we enable S2 translation. 213 */ 214 __sysreg32_restore_state(vcpu); 215 __sysreg_restore_state_nvhe(guest_ctxt); 216 217 __load_guest_stage2(kern_hyp_va(vcpu->arch.hw_mmu)); 218 __activate_traps(vcpu); 219 220 __hyp_vgic_restore_state(vcpu); 221 __timer_enable_traps(vcpu); 222 223 __debug_switch_to_guest(vcpu); 224 225 do { 226 /* Jump in the fire! */ 227 exit_code = __guest_enter(vcpu); 228 229 /* And we're baaack! */ 230 } while (fixup_guest_exit(vcpu, &exit_code)); 231 232 __sysreg_save_state_nvhe(guest_ctxt); 233 __sysreg32_save_state(vcpu); 234 __timer_disable_traps(vcpu); 235 __hyp_vgic_save_state(vcpu); 236 237 __deactivate_traps(vcpu); 238 __load_host_stage2(); 239 240 __sysreg_restore_state_nvhe(host_ctxt); 241 242 if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) 243 __fpsimd_save_fpexc32(vcpu); 244 245 __debug_switch_to_host(vcpu); 246 /* 247 * This must come after restoring the host sysregs, since a non-VHE 248 * system may enable SPE here and make use of the TTBRs. 249 */ 250 __debug_restore_host_buffers_nvhe(vcpu); 251 252 if (pmu_switch_needed) 253 __pmu_switch_to_host(host_ctxt); 254 255 /* Returning to host will clear PSR.I, remask PMR if needed */ 256 if (system_uses_irq_prio_masking()) 257 gic_write_pmr(GIC_PRIO_IRQOFF); 258 259 host_ctxt->__hyp_running_vcpu = NULL; 260 261 return exit_code; 262 } 263 264 void __noreturn hyp_panic(void) 265 { 266 u64 spsr = read_sysreg_el2(SYS_SPSR); 267 u64 elr = read_sysreg_el2(SYS_ELR); 268 u64 par = read_sysreg_par(); 269 struct kvm_cpu_context *host_ctxt; 270 struct kvm_vcpu *vcpu; 271 272 host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt; 273 vcpu = host_ctxt->__hyp_running_vcpu; 274 275 if (vcpu) { 276 __timer_disable_traps(vcpu); 277 __deactivate_traps(vcpu); 278 __load_host_stage2(); 279 __sysreg_restore_state_nvhe(host_ctxt); 280 } 281 282 __hyp_do_panic(host_ctxt, spsr, elr, par); 283 unreachable(); 284 } 285 286 asmlinkage void kvm_unexpected_el2_exception(void) 287 { 288 return __kvm_unexpected_el2_exception(); 289 } 290